AUdIoCoUrSeS
Joined: 31 Oct 2002
Posts: 2014
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| Week 9 - Midi And Recording |
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This is the biggest it gets and it's easier after this one, let me know if u need help.
Good luck
1. Describe the following equipment used by a DJ: Cartridge and stylus, Pickup arm, Turntables, Mixer.
2. Why cannot the output of the cartridge be connected directly to a mixing console?
3. Why is it convenient to DI a synthesizer?
4. Comment on the stereo output of many synthesizers?
5. Why might it be desirable to amplify and mic up a synthesizer, as you would an electric guitar?
6. Comment on the use of loops in recording.
7. Comment on tape loops.
8. Comment on looping using a sampler and sequencer.
9. Why is the sample looped using the sequencer in preference to looping it in the sampler?
10. Comment on the significance of synchronizing the sequencer to multitrack tape.
11. Comment on the suitability of audio sequencers for sample looping.
12. What is timecode?
13. Comment on LTC, VITC and MTC.
14. Comment on MIDI Clock.
15. Why is it desirable to synchronize two MIDI units via MIDI Clock?
16. How does MTC correspond to MIDI Clocks and Song Position Pointers?
17. Why is it desirable to synchronize a sequencer to multitrack tape?
18. Comment on the two stages of building up a recording on multitrack tape with the aid of a sequencer.
19. What is an audio sequencer?
20. Is an audio sequencer suitable as a replacement for a multitrack tape recorder (analog or digital)?
21. Comment on the suitability of an audio sequencer for sample and loop editing?
22. Why is it not straightforward to synchronize an audio sequencer to multitrack tape?
23. What parameters of effects can often be controlled via MIDI?
24. Why would you want to control effects parameters by MIDI?
25. Does MTC come in all the frame rates of SMPTE/EBU timecode?
26. Does MTC contain an address?
27. Does MTC contain a clock?
28. Is MTC useful for synchronizing a MIDI sequencer?
29. Is MTC useful for synchronizing digital audio?
30. Is MTC useful for synchronizing analogue audio?
31. Comment on the difference between standalone hard disk recorders and computer based hard disk recorders.
32. Why is it a problem to use hard disks for long term storage?
33. Onto what media does backup/archival storage take place?
34. What are the advantages of standalone hard disk recorders (compared to tape) for editing?
35. What are the advantages and disadvantages of computer based hard disk recorders compared to standalone hard disk recorders?
36. Comment on the use of Pro Tools as an accessory to multitrack tape.
37. List the common digital multitrack tape formats and describe their characteristics.
38. What is 'formatting'?
39. What are the advantages and disadvantages of digital multitrack compared to analogue multitrack?
40. Compare the maintenance and cleaning of an analogue recorder to that of a digital recorder?
41. Who carries out routine maintenance?
42. Describe how the heads and guides of an analogue machine are cleaned. Mention the materials used.
43. Describe how the pinch roller of an analogue machine is cleaned. Mention the materials used.
44. What are the effects of neglecting cleaning?
45. Why must an analogue machine be periodically demagnetised?
46. What happens if a machine is never demagnetised?
47. What might happen if the demagnetised is operated incorrectly?
48. Why do analogue tape recorders need to be lined up?
49. Do digital recorders ever need to be lined up?
50. Comment on the three elements of line up.
51. Explain the need for monitoring in sync.
52. Why is the sync signal inferior to the playback signal?
53. Why does this matter in track bouncing?
54. Is it possible to edit 2" analogue tape?
55. Is it possible to synchronise two 24-track recorders?
56. Why is it often considered better to use an integrated disk recording system rather than one that uses a personal computer as the user interface?
57. Comment on the presentation of some disk recorders as replacements for tape multitrack recorders.
58. If a tape recorder has 24 inputs and 24 outputs, how many tracks will it have?
59. How many inputs and outputs would a disk recorder need if it was to be a replacement for a 24-track tape recorder?
60. If a disk recording system had two inputs, two outputs, and was capable of twenty-four tracks, what would be its main limitations?
61. What information is stored in the session file?
62. Are session files usually transportable between different systems?
63. Comment briefly on the suitability of SCSI, ATA and Firewire disks for audio recording.
64. What is 'fragmentation'?
65. Comment on archiving to CD-ROM.
66. What are 'virtual tracks'?
67. What is meant by 'edit density'? What are the implications of high edit density?
68. Does the editing and trimming of regions delete audio data from the disk?
69. In editing, what is the difference between 'slip' and 'grid' modes?
70. When might it not be possible to create a crossfade?
71. What is 'bouncing', in the context of mixing?
72. What is meant by 'latency'? What is the difference between DSP processing and host-based processing?
_________________
It's all in the ears. - Learn the concepts not the software.
Audio Courses is a way into the music business for you
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Mon Oct 24, 2005 8:28 am |
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Polarman
Joined: 24 Jun 2005
Posts: 55
Location: Barbados |
| "Studio Recording Engineer" |
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Hi Ben or Chris,
I am reading about this reference software "Studio Recording Engineer" are we supposed to download it or is that something that is outdated/not used anymore?
Or is it something we get after the course?
Kris |
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Wed Oct 26, 2005 9:15 pm |
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AndyBarber
Joined: 09 Sep 2005
Posts: 18
Location: North Wales |
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Posted: Mon Oct 24, 2005 6:28 pm Post subject: Week 9 - Midi And Recording
ANDY BARBER
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1. Describe the following equipment used by a DJ: Cartridge and stylus, Pickup arm, Turntables, Mixer.
The cartridge houses a record players needle (stylus) which turns a record’s ridges into sound. They are designed to provide different levels of skip-resistance (different weights) and output. Dirty or worn down stylus can cause a lot of damage to a vinyl record. The cartridge is held in place by a pickup (tone) arm which allows it to move over a record as it plays. A counterweight is attached to the other end of the arm so there is not too much pressure placed on the stylus.
The turntables (decks) consists of a spinning platter on which the records are placed. There are two mechanisms for turning the platter, belt drive and direct drive. The speed (pitch) of the turntables are variable.
The mixer allows two audio signals to be blended into one output with a cross fader controlling which signal you hear more. Gain and EQ controls are usually available for each channel.
2. Why cannot the output of the cartridge be connected directly to a mixing console?
Cartridge turns information picked up by stylus into an electrical signal. A pre-amplifier and reverse RIAA filtering are required to turn the low level signal a cartridge delivers into one that matches other hifi line level devices (ie. Mixing console).
3. Why is it convenient to DI a synthesizer? (Direct Input/Injection)
If a synth has only one output a DI box can be used to turn it into a two output signal. Used to interface synth with standard balanced inputs of a mixer. (matching synth and mixer’s impedance to reduce interference and hum)
4. Comment on the stereo output of many synthesizers?
Stereo outputs are required to reflect the stereo nature of patches so effects like pan/autopan/delay
can be utilized. Most synths have more than one stereo pair output.
5. Why might it be desirable to amplify and mic up a synthesizer, as you would an electric guitar?
It would be desirable if the synth was being used in a live performance. Multiple mics can be used to capture the ambience of a room being recorded in, giving a live feel to the synth sounds. Amplifier and microphone characteristics will also be included in the signal.
6. Comment on the use of loops in recording.
Useful when recording vocal or instrument part for a track. Achieving a perfect reocrding first time is rare. With loop recording, multiple versions of the part can be recorded, then later selecting most successful parts.
7. Comment on tape loops.
Loops of pre-recorded magnetic tape which are used to create repetitive, rhythmic musical patterns. Tape is usually cut and spliced end to end creating loop which can be played on a reel to reel machine. There are also a number of effects (ie. Phase effects) created with this technique.
8. Comment on looping using a sampler and sequencer.
A sampled loop’s start and end points can be accurately located within a sampler. A sequencer can be used to trigger the sampled loop in a number of ways. The sampler can be made to;
- continuously loop the sample as long as a key is held down
- play the loop all the way through once when a key is pressed (one-shot)
9. Why is the sample looped using the sequencer in preference to looping it in the sampler?
If a sample is looped continuously in a sampler it will eventually start to playback out of sync. Triggering a sampled loop periodically with a sequencer using MIDI will keep the sample playing in time.
10. Comment on the significance of synchronizing the sequencer to multitrack tape.
Sequencers acts as a cross between multitrack tape recorder and a computer. The sequencer will act as a slave to the multitrack. This allows MIDI parts to be written in sequencer with acoustic parts (recorded instruments) on multitrack tape both working as one.
11. Comment on the suitability of audio sequencers for sample looping.
Programs like ‘ACID’ are a good alternative to hardware sampling but are probably not as reliable for live shows. Virtual tracks are used to play back samples (can have as many tracks as RAM and CPU can handle).
12. What is time code?
This is a digital code which is used to keep like minded equipment synchronised in real time. Timecode is a form of media metadata. Used to identify a specific point in time. Standard is SMPTE. Consists in representing addresses for events in a precise way using;
- Hours, Minutes, Seconds and Frames
13. Comment on LTC, VITC and MTC.
LTC (Linear/Longitudal Timecode)
Encodes SMPTE timecode data as a Manchester-Biphase encoded ‘audio’ signal.
VITC (Vertical Interval Timecode)
SMPTE timecode is embedded as black-and-white bars in a pair of the normally unseen vertical interval lines in a TV signal. SMPTE encoded in ‘video’ signal.
MTC (MIDI Timecode)
Digital conversion of SMPTE timecode. Embeds the same timing information as standard SMPTE time code but as a series of small 'quarter-frame' MIDI messages. MTC is a means of transferring timecode around a MIDI system. (there are 24 frames per second)
Quarter frame message is sent periodically to keep track of the running SMPTE time and is analogous to a MIDI clock message. By time slave has received 4 quarter frame messages a SMPTE Frame has passed, so Quarter Frame messages provide a sub frame clock reference. It takes 8 quarter frame messages to convey current SMPTE time.
14. Comment on MIDI Clock.
Timing message sent by master to keep slaves devices in sync with it. MIDI clock message are sent at regular intervals at a rate based upon master’s tempo. There are 24 MIDI clocks sent in every quarter note.
Clock sync = tempo based (relative time)
Timecode = time based (absolute time)
15. Why is it desirable to synchronize two MIDI units via MIDI Clock?
So that two units can play together in sync with each other at the ‘same temp’. Only one source clock can be used so one device has to act as master, the other slave.
16. How does MTC correspond to MIDI Clocks and Song Position Pointers?
MTC messages are an alternative way to keep 2 MIDI devices in sync instead of using MIDI Clocks and Song Position Pointer messages. MIDI clock is MTC’s more musical cousin
17. Why is it desirable to synchronize a sequencer to multitrack tape?
Allows sequencer to play live alongside tape recorder all the way to mix down. MIDI sounds aren’t as committed as sounds recorded to tape and can be arranged/changed more easily. Tape recorder can be used exclusively for acoustic recordings. Both have advantages and disadvantages so combination is best. Using both allows more tracks to be played at the same time.
18. Comment on the two stages of building up a recording on multitrack tape with the aid of a sequencer.
Firstly an SMPTE timecode is recorded as an audio signal onto one of the tape’s tracks using a time-code generator. (digital multitrack can generate SMPTE timecode electronically and don’t require a separate track).
An SMPTE converter is then required to convert SMPTE timecode from multitrack into MIDI timecode (MTC). MIDI interface reads MTC and sends it to the sequencer. Sequenced tracks can then be recorded to mutitrack
On analogue multitrack one tape track is required for timecode.
Its easier to control playback speed of sequencer than tape recorder. Best keep multitrack recorder as master in setup.
19. What is an audio sequencer?
A computer software package that can record, play back and edit audio data
Multi-Track Recording Software can record multiple sources simultaneously.
20. Is an audio sequencer suitable as a replacement for a multitrack tape recorder (analog or digital)?
Virtual tracks are used instead of separate analogue tracks on a tape. They are suitable but are limited by CPU power, amount of RAM, hard disk space and number of inputs/outputs available on audio interface.
21. Comment on the suitability of an audio sequencer for sample and loop editing?
Modern audio sequencers are excellent for sampling and loop editing. Some have built in facilities but there are many other programs designed specifically for manipulating and editing samples to be played back/looped. A graphical interface and cut, copy, paste facilities make audio editing easy on a computer.
22. Why is it not straightforward to synchronize an audio sequencer to multitrack tape?
Both use different time codes. Tape(LTC) with Sequencer(MTC)
Electronic box is required to interface the MTC signal with tape
23. What parameters of effects can often be controlled via MIDI?
MIDI is an electrical digital signal that conveys a hardware instruction. Parameters of external effects hardware can be controlled via MIDI provided a digital system is used by the effects unit with a MIDI port available.
If there are plugin effects available to audio sequencer virtually all of the parameters can be automated.
24. Why would you want to control effects parameters by MIDI?
So effects can be automated in real-time (creates time varying effects)
25. Does MTC come in all the frame rates of SMPTE/EBU timecode?
Yes, MTC is a digital conversion of SMPTE and both are used to represent absolute time.
All SMPTE variants have a MTC equivalent.
Every frame of SMPTE timecode is broken down into 4 frames of MIDI time code
MIDI device must read two frames of code before it knows
26. Does MTC contain an address?
Yes a MTC message contains address information
(MTC is a continuous message and is a form of frame accurate sync)
The time code address is given in hours, minutes, seconds and frames
27. Does MTC contain a clock?
NO, MTC works with absolute time and is independent of musical tempo.
Clocks are based upon musical beats from the start of a song.
28. Is MTC useful for synchronizing a MIDI sequencer?
Yes, MTC allows MIDI devices to lock to SMPTE Time code in real time. This would allow a sequencer to be in sync (as a slave) with a multi-track recorder or video player. All current MIDI sequencing software is compatible with MTC.
29. Is MTC useful for synchronizing digital audio?
Yes, MTC can be used to sync a sequencer with other digital audio systems provided they have a MIDI port. The clock for sequencer’s internal digital audio is provided by audio card/interface. MIDI and audio are slaved to the same clock.
30. Is MTC useful for synchronizing analogue audio?
MTC is a digital message system and can’t be used to sync analogue audio like a multitrack tape recorder. A standard SMPTE code would be used.
31. Comment on the difference between standalone hard disk recorders and computer based hard disk recorders.
Computer based HDs are permanently wired to a computer, whereas stand alone HDs can be wired to multiple systems.
32. Why is it a problem to use hard disks for long term storage?
Long-term data is data that needs to be accessible for more than three years. Magnetic Hard disks have breakable moving parts and a usable life of around 3 - 5 years.
33. Onto what media does backup/archival storage take place?
Digital data is generally stored on Hard drives, tape library, RAID array, Optical Devices.
34. What are the advantages of standalone hard disk recorders (compared to tape) for editing?
Tape and Disk storage systems currently run with similar access time, storage density and price. However disks have a wider market in consumer products. Editing audio with hard disks is easier as it takes place in a virtual environment where mistakes can be easily undone (non-destructive editing).
35. What are the advantages and disadvantages of computer based hard disk recorders compared to standalone hard disk recorders?
Computer based HDs are usually connected with an IDE cable meaning only a maximum of two can be used. However they are cheaper than stand alone models.
Stand alone recorders are free standing and are connected by USB or Firewire. Stand alone HDs are more flexible as they offer a portable storage system. (great for laptops). USB and Firewire allows multiple drives to be used together.
36. Comment on the use of Pro Tools as an accessory to multitrack tape.
Pro Tools is simply a multi-track tape recorder without the tape (virtual tape recorder)
Doesn’t host soft synths or MIDI. Modelled on traditional paradigm of multitrack tape recorder, mixer and external effects. Editing in Pro tools is more flexible than working with tape.
37. List the common digital multitrack tape formats and describe their characteristics.
DAT (digital Audio Tape)(Sony)
4mm magnetic tape
Offering sample rates of 32/44.1/48KHz with 16-bit quantization
ADAT (Alesis Digital Audio Tape)
Uses S VHS video tape offering 8 tracks of 16/20-bit audio recorded at 44.1KHz
DASH (Digital Audio Stationary Head)
Uses ½ inch tape offering 2 to 48 tracks to be recorded
Sample frequencies of 44.1, 48KHz are available with up to 24-bit sample rate
DTRS (Digital Tape Recording System)
Uses a Hi8 cassette format offering 8 tracks of 16/24-bit audio recorded at 44.1/48KHz
38. What is 'formatting'?
Formatting is a process which prepares a hard disk (or other storage medium) for use with the file system of an operating system.
39. What are the advantages and disadvantages of digital multitrack compared to analogue multitrack?
Analogue
- needs constant vigilance to sound good
- tape can’t be copied easily
- capacity limited by length of tape
- has warm sound
Digital
- has artificial edge as its highly accurate
- latency problems
- data can be backed up and copied easily with no loss of sound quality
- can record much longer than analogue
- more portable system
- no tape hiss
- non destructive editing
40. Compare the maintenance and cleaning of an analogue recorder to that of a digital recorder?
Analogue recorders are mechanical by nature and need a good deal of attention to perform their best. Heads on recorder acquire build up of tape oxide (fine dust shed from tape) after constant use.
Maintenance for digital recorder is just software updates, no real moving parts with digital.
DAT cleaning cartridges are available but digital systems should be cleaned by an expert.
41. Who carries out routine maintenance?
Routine maintenance for analogue equipment should be carried out by sound engineer. Some digital systems may require a specialist.
42. Describe how the heads and guides of an analogue machine are cleaned. Mention the materials used.
Tape must have a very intimate contact with head to get a good recording. Heads and tape guides must be clean for good results. Heads are cleaned with a cotton swab dipped in a largely Isopropyl alcohol solution.
43. Describe how the pinch roller of an analogue machine is cleaned. Mention the materials used.
Job easily done by yourself. To start remove lid of tape and locate pinch roller. Best to remove it before cleaning. Wash under tap with washing up liquid to clean and make rubber stickier (Isopropyl alcohol can erode the rubber). Play back tape with lid up to check tape is being pulled correctly past the roller.
44. What are the effects of neglecting cleaning?
Unclean recording equipment results in poor sound quality and tape damage (noisier, duller recordings)
45. Why must an analogue machine be periodically demagnetised?
Cleaning and demagnetising should be done on a regular basis.
Cleaning must be done before demagnetising.
Need to ensure that nothing the tape comes into contact with is magnetised in any way. Magnetised heads can cause a recording to have more background noise with partial erasure of higher frequencies.
46. What happens if a machine is never demagnetised?
Tape machines will gradually become magnetised while playing or recording. Without demagnetising, tape would pickup unwanted magnetic interference creating audio anomalies or even complete deletion of audio on tape.
47. What might happen if the demagnetiser is operated incorrectly?
Incorrect operation can leave heads and guides strongly magnetised. This can be caused by turning demagnetiser on or off too close to machine. This creates a sudden creation or collapse of magnetic field which can magnetize a number of things.
48. Why do analogue tape recorders need to be lined up?
Machines environment changes with humidity, temperature and age
Perfect head alignment is the optimum orientation of the tape that provides the most information to the head available from the tape. Makes sure tape will play on other analogue recorders.
49. Do digital recorders ever need to be lined up?
Yes, best done by specialist.
50. Comment on the three elements of line up. ????
There are three types of head in an analogue tape recorder, record, play and erase all of which have to be fine adjusted with regard to their physical alignment. The right Azimuth angle means a head needs to be absolutely vertical with respect to the tape (zenith, wrap and height not as important)
Bias Level - optimises maximum output level, distortion and noise levels
Playback level - should be checked with a calibration tape (1KHz tone) so level aligned to studios electrical standard level
51. Explain the need for monitoring in sync.
When tape is played there is a Delay between playback and recording head due their physical separation.
Monitoring in sync is required when overdubbing onto a multitrack recorder.
With an analogue recorder the monitoring signal has to come from the recording head so that overdubbed tracks are in time with other tracks on the tape.
52. Why is the sync signal inferior to the playback signal?
Record head is optimised for recording, not play back (no special equalisation provided)
53. Why does this matter in track bouncing?
Again track bouncing must be done in sync mode so that any bounced tracks are kept in time with all other tracks. Again there will be a slight loss in signal quality.
54. Is it possible to edit 2" analogue tape?
Originally 2” analogue tape was edited by physically cutting and splicing the tape, in a manner similar to film editing.
55. Is it possible to synchronise two 24-track recorders?
Synchronisation of digital 24-track recorders is easily done. Synching two analogue 24-track recorders is difficult. They both need there own recorded channel of SMPTE time code and can’t be slaved.
Questions 56 - 72
See Questions 1 - 15
RT WEEK6
http://www.iaekm.org/article42.htm
http://arts.ucsc.edu/ems/music/equipment/analog_recorders/Analog_Recorders.html#Cleaning
http://www.audiomidi.com/classroom/proaudio/sync_wordclock.cfm
http://www.soundonsound.com/sos/1995_articles/may95/homestudio3.html
http://www.alesis.com/support/cc/sync.html
http://en.wikipedia.org/wiki/Disk_formatting
http://pages.ebay.com/buy/guides/dj-gear-equipment-buying-guide/#1
http://www.harddisk.com/
http://www.soundonsound.com/sos/1997_articles/may97/tapemaintenance.html
http://www.soundonsound.com/sos/1996_articles/jun96/miditimecode.html
http://www.soundonsound.com/sos/1996_articles/oct96/sampleloops.html
http://www.borg.com/~jglatt/tech/midispec/clock.htm
http://www.music.mcgill.ca/~meyers/multimedia/senior_project/MTC.html
http://music.northwestern.edu/links/projects/midi/pages/miditmcn.html
http://linux.tu-varna.acad.bg/~lig/MIDI/xplained/mx2.htm#sync
http://www.sfu.ca/sca/Manuals/147/ProTools/PT-Advanced.html
http://www.storagesearch.com/view51.html
http://www.saecollege.de/reference_material/pages/Recorders.htm
http://www.mtsu.edu/~dsmitche/rim419/midi/HTMLs/USEMID~1.HTM
Sound Recording, An Introduction, Francis Rumsey, Tim Mccormick |
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Thu Oct 27, 2005 5:13 pm |
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Polarman
Joined: 24 Jun 2005
Posts: 55
Location: Barbados |
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1. Describe the following equipment used by a DJ: Cartridge and stylus, Pickup arm, Turntables, Mixer.
Cartridge and Stylus
Stylus is the needle used to read the grooves in the record. Vibrations are sent from the stylus and picked up from the vinyl to the cartridge. This is where they are transformed into electrical impulses and allows the sound to be produced. Today the most commonly used cartridge is the Stanton 500AL, the reason being its overall durability and sound quality.
Pickup arm
The part of the turntable that reaches over to the vinyl is called the tome arm. At one end of the tone arm is the stylus and at the other is the counter weight. An electrical signal from the cartridge is passed along the tone arm and into the turntable which takes the signal into the mixer. The tone arm height can be adjusted on the high quality in order to change the pressure of the stylus on the vinyl. Also, there are other ways for the pressure to be adjusted just in case the turntable does not have the facility to change the pressure if the stylus on the vinyl.
Turntables
Belt Drive
The platter on a belt drive turntable is driven by a large rubber band. There is a small motor inside the turntable that gives the driving force and the band links this to the actual platter. The time it takes for a belt driven turntable to get up to the required speed is one of the main disadvantages. This problem is known as the torque and different decks have different torque values. The higher the value the better, because it allows the turntable to get up to top speed much faster. Belt drive turntables tend to have low torque values. Another drawback with the belt drives can be found when making slight adjustments to the pitch during beat matching. The response of the turntable tends to be sluggish, meaning that when the change in pitch is made, the platter doesn’t respond right away. This creates problems for the mix.
Direct Drive
A motor is fixed directly under the platter on direct drive turntables. The platter is driven by the motor and there is no need for a belt. Therefore it is called 'direct' drive. The decrease in time taken for the platter to get up to speed (pick up time) is the main advantage of direct drive. The pick up time is important when using skills such as scratching. Another advantage is the higher response when the pitch is changed. This is necessary when beat matching.
Mixer
The audio out sockets are used to connect the turntable to a controller, normally an amplifier or hi-fi of some kind but in the case of a DJ, it will connect to a mixer. By doing this, the DJ now has volume control over individual channels where the turntable will plug into.
http://www.djsource.co.uk/tutorials/dj-equipment/the-turntable-a-dj-equipment-tutorial/
2. Why cannot the output of the cartridge be connected directly to a mixing console?
There are mainly three reasons why the output of the cartridge cannot be connected directly to a mixing console:
- The Line level of the mixer is usually around 0.775 V and the output level of the cartridge is usually much around 5 mV.
- The input impedance of a mic input is around 2 kilo ohms which is too low for the cartridge which have a required input around 47 kilo ohm.
- RIAA EQ is used in the cutting process of vinyl to achieve satisfactory playback duration. This reduces LF and is compensated by reverse RIAA EQ in the cartridge input stage. Normal mic and line inputs do not have this (http://www.dmxl.net/qdl/mtandrecordingqdl.html)
3. Why is it convenient to DI a synthesizer?
It is convenient to DI a synthesizer because you don’t have to use mics and you get a synthesisers pure sound without any room ambience.
4. Comment on the stereo output of many synthesizers?
Many out puts of synthesizers stereo outputs is not a “real stereo signal” it are a simulation done with a chorus effect.
5. Why might it be desirable to amplify and mic up a synthesizer, as you would an electric guitar?
Some engineer finds the direct out of a synth very cold and unnatural. Using an amplifier or tap out the recorded signal into a echo chambers adds natural warmth and feeling to the sound (Owsinski, 1999)
6. Comment on the use of loops in recording.
Sections that are played over and over again in a song can be looped instead of recorded all way through. Examples of sections could be a kick drum in dance music or a chorus. Normally looping is used when a monotonic sound is what one looks for. The loops part can be either recorded audio or MIDI data. One thing that is close to looping is to only record the background vocals once and then paste the actual sections out into each chorus.
7. Comment on tape loops.
Tape loops are loops of prerecorded magnetic tape used to create repetitive, rhythmic musical patterns. A measure of recorded magnetic tape is cut and spliced end to end, creating a circle or loop which can be played continuously, usually on a reel to reel machine. Tape loop effects are often combined with glissando, a technique wherein the playback speed of the loop is increased or decreased over time.
Simultaneous playing of tape loops to create phase patterns and rhythms was developed and initially used by musique concrète and tape music composers, and was utilized by Steve Reich for his "phasing" pieces, and by Karlheinz Stockhausen.
Beginning in the late 1950s the BBC Radiophonic Workshop began using tape loops for to add special effects to some BBC programming.
Pop musicians, most notably The Beatles, Can, and Pink Floyd, have used tape loops on their albums.
In the early 1970s, musicians Brian Eno and Robert Fripp created Frippertronics, a system for creating tape loops during a live performance. Digital sampling -- which can generally provide similar results with less effort -- overtook much tape loop use, beginning in the mid 1980s. Some musicians and composers, however, continue to use tape loops for various reasons.
http://en.wikipedia.org/wiki/Tape_loop.
8. Comment on looping using a sampler and sequencer.
When one uses a sampler in combination there is no need to set the loops inside the sampler. The sequencer I s used to set the loop timings with duration of midi notes.
9.Why is the sample looped using the sequencer in preference to looping it in the sampler?
When the sample is triggered using the sequencer the loop will be retriggered with an interval, in this way the tempo/start of the sample will not glide in time. When the sample is looped in the sampler slight timing problem can occur according to the set tempo.
10. Comment on the significance of synchronizing the sequencer to multitrack tape.
When using a sequencer together with a multi track tape it is very important that the synchronisation is correct. Even slight different in milliseconds will spoil the results. Here it is important to set the multitrack tape as master and let the sequencer follow the tape since the tape is less stable.
11. Comment on the suitability of audio sequencers for sample looping.
Audio sequencers are very suitable for sample looping. Once the sound is recorded it is easy to edit the part and cut and paste it out for repetition. Of course this is different among different sequencers and if it is hardware or a software sequencer. Looping is though regarded as a basic feature.
12. What is timecode?
Time code is the standard method of interlocking audio, video and film transports. The code was developed by Society Motion Picture and Television Engineers (SMPTE). The address code cannot slip and keeps it accuracy from 1/24th to 1/30th of a second.
13. Comment on LTC, VITC and MTC.
LTC
LTC stand for Longitudinal Time Code and is a time code recorded on analog or video cue track. LTC encodes biphase time code signal onto analog audio or cue track in the form of a modulated square wave at a bit rate of 2400 bits/second. It can be difficult to record a perfect square wave on a magnetic audio track so SMPTE has an allowable rise time of 25 plus minus 5 microseconds for the recording and the reproduction of valid code. LTC can be read 1/10th slower and 1/20th speed higher than normal speed (Huber & Runstein, 2005).
VITC
VITC (Vertical Interval Time Code) is used by major video production houses. VITC has the same address and user code as LTC but one difference is that VITC is encoded onto video tape with the time code encoded into the video signal by itself inside a field located outside the visible picture. Because of that helical video recorders are able to read time code at very slow or even still frame rate (Huber & Runstein, 2005).
MTC
MTC (MIDI Time Code) translates time code into messages that can be transmitted via MIDI. MTC allows production environments to easily translate time code into to time-stamped messages that can be transmitted via MIDI. This allows MIDI devices to be locked and triggered to SMPTE time code. MTCs second purpose or part is to make it possible to inform MIDI devices of an upcoming event that has to be performed at a specific time such as load, play, stop, Punch in/out, reset). MTC is made up of three message types: quarter frame messages, full messages and MIDI cuing messages (Rumsey, 2004).
- Quarter frame
This is transmitted when the system is running in real or variable speed time in either forward or reverse direction. Four quarter frame messages a generated for each time code frame. A full SMPTE address needs 8 quarter frame messages the, SMPTE address is updated every two frames. That means that 25fr/sec is 100 quarter frame messages would be transmitted every second. Each quarter frame contains 2 bytes (the common header and the message number with the encoding of the time filed digit) (Rumsey, 2004).
- Full messages
Quarter frame messages can’t be sent in fast forward/reverse/locate because it would clog the MIDI data line. When in one of these modes a full message is sent to encode a complete time code address within a single message. Once playback again MTC will send quarter frame messages (Rumsey, 2004)
- MIDI cueing messages
These messages are used to address individual devices or program within a system. It’s a thirteen bit message that could instruct play, punch in, load, stop etc. (Huber & Runstein, 2005)
14. Comment on MIDI Clock.
The timing clock is a single status byte and it is issued by the controlling device six times per MIDI beat which is equivalent to a sixteenth note. The timing clock byte can temporarily interrupt other MIDI messages which are necessary since it is a synchronising message. The time clocks synchronising byte can appear between two data bytes of a note message. The receiving device increments its internal clock by the amount sent by the sending device (Rumsey, 2004)
15. Why is it desirable to synchronize two MIDI units via MIDI Clock?
MIDI Clock is a simple and easy way to keep two MIDI devices in sync.
16. How does MTC correspond to MIDI Clocks and Song Position Pointers?
MTC is used instead of MIDI Clocks and Song Position Pointers when real time synchronisation is important and not beats or note values. This can be for example when synchronising for video. With timecode the locations will be remained in the same place even if the musical tempo is changed. That is not the case with MIDI Clocks and song position pointers (Rumsey, 2004).
17. Why is it desirable to synchronize a sequencer to multitrack tape?
When using a sequencer together with a multi track tape it is very important that the synchronisation is correct. It’s very hard and costly to sync the multitrack recorder to the sequencer since the tape will fluctuate in speed. Therefore is desirable to synchronise the sequencer to the multitrack.
18. Comment on the two stages of building up a recording on multitrack tape with the aid of a sequencer.
The first stage is to stripe the highest track on the tape with ascending code from the tapes beginning to the end. Then the code can be routed to the SMPTE interface. Or a box that converts SMPTE to MTC which then can be plugged into a MIDI in to the DAW or sequencer. It’s always cheaper to let the sequencer or the DAW act a slave and the tape act as master (Rumsey, 2004).
19. What is an audio sequencer?
An audio sequencer (hardware or software) is sequencer capable recording and playback audio information like a multitrack tape. An audio sequencer can edit and manipulate audio information with use of tools and plugins.
20. Is an audio sequencer suitable as a replacement for a multitrack tape recorder (analog or digital)?
Yes an audio sequencer could a suitable replacement for a multitrack recorder but there are some points that need to be raised.
The audio sequencer must be able to record with high sampling rate and high quantisation like 48 KHz and 24 bit resolution. The DA must be of a high quality. If it is a software sequencer the computer has to have a suitable amount of RAM and a fast CPU.
If these criteria are fulfilled there are only advantages with using an audio sequencer instead of a multitrack tape recorder. This discussion is not about analogue contra digital since the question was about tape both analogue and digital) contra sequencer. The analogue/digital debate is another story.
21. Comment on the suitability of an audio sequencer for sample and loop editing?
An audio sequencer is very suitable for sampling and loop editing. Some audio sequencers have better functions then others. Most sequencers today has all tools needed like cut, stretch, paste, reverse etc. The sequencer must also have a good window letting you see the wav for editing.
22. Why is it not straightforward to synchronize an audio sequencer to multitrack tape?
To be able to have the multitrack as the slave costly hardware is needed since the tape machines speed regulator must be connected to a special feedback control loop which allows it to continuously adjust its speed to the master. Therefore it is much cheaper and easier to let the tape machine act as master and the other devices like a DAW to act as a slave (Huber & Runstein, 2005).
23. What parameters of effects can often be controlled via MIDI?
Normally all parameters of effects can be controlled via MIDI.
24. Why would you want to control effects parameters by MIDI?
Controlling effects via MIDI lets you control and record effect parameters in real time. One way to do this is to assign specific parameters to an external MIDI device with knobs or faders.
25. Does MTC come in all the frame rates of SMPTE/EBU timecode?
Yes the frame rate is coded in the Hour part of the time code value as follows:
00 = 24 fps
01 = 25 fps
10 = 30 fps drop fram (29.97 fps NTSC)
11 = 30 fps non drop frame
(Rumsey, 2004)
26. Does MTC contain an address?
Yes MTC converts SMPTE addresses to binary code. Since MTC needs 8 quarter frame messages to encode a full SMPTE address the complete frame address is updated every second frame. So in a 30fps setting the address is only updated 15 times / sec. (Huber & Runstein, 2005).
27. Does MTC contain a clock?
No, MTC does not contain a clock. MTC converts addresses and sync according to these addresses.
28. Is MTC useful for synchronizing a MIDI sequencer?
Yes is a cheap way to synchronise a MIDI sequencer.
29. Is MTC useful for synchronizing digital audio?
MTC is suitable to synchronise digital audio since it tied to absolute time (hours, minutes, seconds, frames).
30. Is MTC useful for synchronizing analogue audio?
MTC is suitable to synchronise analogue audio since it tied to absolute time (hours, minutes, seconds, frames). MTC can translate the recorded SMPTE code recorded on the tape. It’s important to have the analogue tape as master.
31. Comment on the difference between standalone hard disk recorders and computer based hard disk recorders.
Advantages of a standalone hard disk recording system over computer based hard disk recorders are that the integrated disk system is designed for recording only. It has been built, tested and tweaked for the purpose. If problems or questions arise there is one point of contact since the whole system has been designed by one company. A computer is built for other purposes then audio. The hardware can be manufactured from many different companies and sometimes a specific hardware doesn’t work with the rest of the computers hardware, some software doesn’t work with a specific hardware etc. Some people also have the view that an integrated disk recording system lets you concentrate on your music rather then loose time on upgrading, installing plug-ins, debugging etc.
32. Why is it a problem to use hard disks for long term storage?
The most reliable long-term storage is the magneto-optical disk. The removable magnetic hard disk is unreliable and unpredictable when it comes to long-term storage. Hard disks are mechanical and at some point will fail. When they do fail, it can be costly and time consuming to retrieve the information on them (http://www.minidisc.org/dat_archiving.html)
33. Onto what media does backup/archival storage take place?
Optical storage such as CD-R, DVD should be used for long term storage of digital information. Long term storage should however not be done on any rewritable optical storage.
34. What are the advantages of standalone hard disk recorders (compared to tape) for editing?
Advantages of editing with standalone hard disk recorders compared to tape are first of all non-destructive editing. This means that you can easily listen to your edit directly and regret the edit and undo it. With tape this is not easy that’s why you have to be brave editing tape…
With hard disk recorders you can copy a whole verse or single tracks and paste it out easily while with tape this is almost impossible.
35. What are the advantages and disadvantages of computer based hard disk recorders compared to standalone hard disk recorders?
Advantages
- You can upgrade your system with new hard ware and software letting you to follow the evolution of technology.
- You can make the system more suitable for your likening. Its easy to expand and implement new functions.
- Good visual overview of everything you do (can be a disadvantage feeding your eyes instead of your ears…
- Cheaper then a standalone hard disk recorders, normally you even have a computer already.
Disadvantages
- Since the computer is not primarily built for music recording its not tested and tweaked for this purpose. If you have chosen wrong hard ware contra software the system can be unstable.
- Hard to know the source of a problem, hardware or software.
- Many points of contacts, hardware manufactures and software manufactures etc.
- Not easy to carry around from place to place if not a lap top system.
- A computer based system demands a certain technical knowledge to setup and run.
36. Comment on the use of Pro Tools as an accessory to multitrack tape.
Pro Tools can be used as a post production tool. If the sound of analogue tapes is preferred the tracks can be transferred over to the digital domain after recording. When the tracks are converted to the digital domain Pro tools can be used to processing and adding of effects.
37. List the common digital multitrack tape formats and describe their characteristics.
The common digital multitrack tape formats are DASH, ADAT, and DTRS.
DASH
The width of the tape used for both 24-track and 48-track DASH is ½ inch (12.55 mm) open reel
The 24-track is totally two-way compatible with 48-track. They are both forward and reverse compatible. If you record your project on a 24-track and feel that you don’t have enough tracks you can just change to a 48-track and get 24 extra tracks. If you start on a 48-track and only use 24-track you can change to a 24 track and do you mix. DASH was designed to be a cut-and-splice editing format like on a analogue tape but the most used way to edit on DASH is by copying between two machines synchronized together with an offset. The playback head on a DASH comes before the record head because digital operations take time while analog processes take place instantaneously. Since you have a delay processing the signal to put it on the tape, when overdubbing the delay is avoided with having the playback head before the record head.
A DASH should be cleaned by an expert. To clean a DASH you need special tools and a DASH should not be cleaned with cotton like an analogue tape recorder.
ADAT
ADAT is used in pro-, semipro- and budget music recording studios. ADAT was created by Alesis Corporation. It uses a rotary head, records 8- tracks and uses S-VHS. Two or more systems can be connected via light pipe cable.
DTRS
DTRS is used in broadcast and film post-production. It uses a rotary head and was created by Tascam. It has 8 –tracks and can record up to 108 minutes on to a standard 120 min Hi-8-mm video tape. It can be combined with other DTRS recorders. Digital I/O is made with TDIF connection.
38. What is 'formatting'?
It is necessary to format all digital recording mediums before use. The formatting on DAT is carried out during recording. However, it is often better to format in advance on DASH. In Advance Record mode the machine can format while recording. This is however best done when the whole tape will be recorded without stopping. The tape can be `pre-formatted´ but this is time consuming. It can however be done in one quarter of real time, and the machine will lay down timecode simultaneously.
(http://www.dmxl.net/coursenotes/digitaltaperecording.html)
39. What are the advantages and disadvantages of digital multitrack compared to analogue multitrack?
Advantages
Both machines and tapes are cheaper.
Needs less maintenance
Disadvantages
The different standards are not compatible between each other.
Since its digital it needs professional people to locate problems.
40. Compare the maintenance and cleaning of an analogue recorder to that of a digital recorder?
Normally in a studio, an analog recorder should be cleaned by a recording engineer. To avoid damage to a DASH machine, it should only be cleaned by an expert. A special chamois-leather cleaning tool should be used to clean the heads. This should only be done in a wiping horizontal motion. Cotton buds, as used for analog records will clog a DASH head with their fibers. Similarly, an analog record can be aligned by a knowledgeable engineer, but alignment of a DASH machine should be done every six months by a suitably qualified engineer. Using a portable PC and a special test jig, the engineer runs special service software on the portable PC which can interrogate every aspect of the DASH machine. It checks head hours, error rates, remote ports, sampler card etc. Even the heads and tape tension can be aligned.(http://www.midi-sequencer.com/technology_sound_digital%20recording_dash_maintenance.html)
41. Who carries out routine maintenance?
Analog recorder – a knowledgeable recording engineer
Digital recorder – a qualified engineer
42. Describe how the heads and guides of an analogue machine are cleaned. Mention the materials used.
Cleaning the heads is a simple process. You should use a safe tape head cleaner containing trichlorotriflouroethane, or pure (97% 99%) isopropyl alcohol. Do NOT use rubbing alcohol-it contains water. Dampen a soft cotton swab with the cleaner and rub it up and down the heads. This isn't a dainty process-don't rub the heads hard enough to push them out of alignment, but press hard enough to ensure a complete cleansing. Clean everything in the tape path, but be careful with the pinch roller. The tape head cleaner mentioned is considered safe for use on rubber, but alcohol can damage it. If you want to be safe, clean it with a lint free cloth dampened with water
Be careful when cleaning the capstan that you don't use too much fluid. The capstan is literally the shaft of the capstan motor, and the cleaning fluid or even water dripping down into the motor can dry out the bearings and wreck the motor over time.
A convenient way to clean the capstan is to trick the machine into thinking it has tape in the tape sensor, which will cause the capstan to start spinning. Now you can dampen your cotton swab with the head cleaner you're using and run the swab up and down the capstan slowly, which will clean the surface all the way around it (http://www.churchsoundcheck.com/tra.html)
43. Describe how the pinch roller of an analogue machine is cleaned. Mention the materials used.
To clean the pinch roller, once again fool the machine into thinking that tape is one the transport, and put the machine into PLAY mode. This will shove the pinch roller up against the capstan, causing it to spin along with the capstan. Clean the pinch roller as discussed above. If the pinch roller is really dirty, and it can easily be removed, undo the cap that holds it in place and hold it in your hands or in your lint free cloth as you clean it. This will allow you to scrub harder. Many engineers rely on a household cleaning product called Formula 409 to clean the pinch roller (and only the pinch roller). It does a good job of cleaning off the oxide and leaves the rubber soft and supple. Not knowing for sure if 409 will leave any residue on the roller, I typically follow that up with the trichlorotriflouroethane or a water dampened lint free cloth.
44. What are the effects of neglecting cleaning?
Bad performance: Dust and magnetic build up increases in noise level and causes clicks and splices and some high frequency erasure.
45. Why must an analogue machine be periodically demagnetised?
Analogue tape heads are temporary magnets. But even so some slight magnetic build-up over the passage of time is however inevitable. This causes clicks at splices, increases recorded noise level, and produces some high end frequency erasure. The heads are routinely cleaned with a head demagnetiser (a wand-like instrument which produces a strong magnetic field) in order to remove the effects of the magnetic build up (Recording Engineer 2.0).
46. What happens if a machine is never demagnetised?
Also known as 'degaussing' the heads: After a while, the metal parts will collect a residual magnetism that will partially erase any tape that is played on the machine. A special demagnetizer is used for which proper training is necessary; otherwise the condition can be made even worse (http://www.churchsoundcheck.com/tra.html).
47. What might happen if the demagnetised is operated incorrectly?
The bad operation can get worse then it was before demagnetising.
48. Why do analogue tape recorders need to be lined up?
The reason analogue tape recorders need to be lined up, or aligned is first to get the best out of the machine and the tape and the other is to make sure that a tape played on one recorder will play properly on any other recorder (http://www.audiomasterclass.com/units/body/10analogrecordingbody.html)
49. Do digital recorders ever need to be lined up?
Yes but is has to be done by a certified engineer.
50. Comment on the three elements of line up.
The erase, record and playback heads will often have five adjustments, three of them are:
Azimuth
– the most critical, to avoid cancellation of HF the heads need to be absolutely vertical with respect to the tape.
Wrap
– refers to the angle the tape bends around the head. This also determines sensitivity to drop-outs since it also determines the degree of tape-to –head contact.
Zenith
– refers to the heads tilt towards or away from the tape. Zenith must be adjusted so there is the same force on the top and the bottom of the tape. Bad zenith adjustment results in skewing which results when tape rides down, up or out of its guide (Huber & Runstein, 2005; http://www.audiomasterclass.com/units/body/10analogrecordingbody.html)
51. Explain the need for monitoring in sync.
To be able to do overdubs (listening to recorded material while recording new) the channels that needs to be monitored must be set to sync mode. Otherwise the there would be between the monitored tracks and the newly recorded tracks. The sync mode means that the tracks are played back with their respective record head tracks instead of the playback head (Huber & Runstein, 2005).
52. Why is the sync signal inferior to the playback signal?
Since the record head is optimized for recording not playback the signal is of less quality then it would be when played back with playback head, nevertheless it is good enough for monitoring. The playback head is used for final mixdown (http://www.audiomasterclass.com/units/body/10analogrecordingbody.html)
53. Why does this matter in track bouncing?
Since bouncing has to be done in time with other tracks bouncing has to be done using the sync output of the record head, otherwise. The slight loss of quality has to be tolerated (http://www.audiomasterclass.com/units/body/10analogrecordingbody.html)
54. Is it possible to edit 2" analogue tape?
It is possible to edit two inch tape. It is normal to record three or four takes of the backing tracks of a song, and splice together the best sections. The way it is done is to place the tape in a special precision-machined aluminum editing block. A single-sided razor blade guided by an angled slot is used to cut the tape. Splicing tape is available with exactly the right degree of stickiness to join the tape back together. The editing will be impossible to hear when it is done in the right place (usually just before a loud sound). Nevertheless it takes courage to cut through a twenty-four track two-inch tape.
(http://www.audiomasterclass.com/units/body/10analogrecordingbody.htmlrder)
55. Is it possible to synchronise two 24-track recorders?
Yes if you record SMPTE code on one of the tracks and synchronize them together.
56. Why is it often considered better to use an integrated disk recording system rather than one that uses a personal computer as the user interface?
Advantages of an integrated disk recording system over a personal computer are that the integrated disk system is designed for recording only. It has been built, tested and tweaked for the purpose. If problems or questions arise there is one point of contact since the whole system has been designed by one company. A computer is built for other purposes then audio. The hardware can be manufactured from many different companies and sometimes a specific hardware doesn’t work with the rest of the computers hardware, some software doesn’t work with a specific hardware etc. Some people also have the view that an integrated disk recording system lets you concentrate on your music rather then loose time on upgrading, installing plug-ins, debugging etc.
57. Comment on the presentation of some disk recorders as replacements for tape multitrack recorders.
The presentation gives many reasons for replacing tape multitrack recorders with disk recorders. One is the price and that expensive tape is not needed any more, less maintenance and easier to use. What the advertisers often miss is the amount of inputs/outputs needed to replace a multitrack see questions below.
58. If a tape recorder has 24 inputs and 24 outputs, how many tracks will it have?
A tape recorder with 24 inputs and 24 outputs would have 24 tracks.
59. How many inputs and outputs would a disk recorder need if it was to be a replacement for a 24-track tape recorder?
A disk recorder would need (at least) 24 inputs and outputs to replace a 24-track tape recorder.
60. If a disk recording system had two inputs, two outputs, and was capable of twenty-four tracks, what would be its main limitations?
The main limitation would be that you are only able to record two tracks at a time. There are also limitations when it comes to adding effects since you only have two inputs/outputs if there are no additional sends or returns.
61. What information is stored in the session file?
The information stored in a session file is the track assignments, mixer settings, the edits, the audio files used, project title, VST and plug-in information.
62. Are session files usually transportable between different systems?
No usually not since different systems uses different structures to save the data. Open Media Framework Interchange (OMFI) is a platform independent file format intended for transfer of digital media between different applications. Cubase SX can import and export OMF files (file extension .omf), allowing you to use Cubase SX in conjunction with other audio and video applications.
The exported OMF file will contain (or make reference to) all audio files that are played in the project (including fade and edit files). It will not include unused audio files referenced in the Pool, or any MIDI data. Video files are not included, but Cubase SX stores the start positions of Video Events in the OMF file, allowing you to manually import video files in another application that can import omf format like Protools (as usual it cost extra in Protools to be able to do that…). (Cubase SX3 Operation Manual, 2004).
63. Comment briefly on the suitability of SCSI, ATA and Firewire disks for audio recording.
In audio production its important with high sustain rates. The difference between these three alternatives is not so much the physical hardware as the difference in controllers and possible bandwith these can tolerate. SCSI is an old standard but is still suitable for audio recording. Firewire is better then ATA.
64. What is 'fragmentation'?
Fragmentation is when files gets divided into pieces scattered around the disk. Fragmentation occurs naturally when you use a disk frequently, creating, deleting, and modifying files. At some point, the operating system needs to store parts of a file in non-contiguous clusters. This is slows down the speed at which data is accessed because the disk drive must search through different parts of the disk to put together a single file.
This is why it is important to always defragment you audio disk after each session.
65. Comment on archiving to CD-ROM.
According to the technical pages of several CD manufacturers estimates vary widely as to the expected longevity of CD-ROMs are estimated to last anywhere from 30 to 200 years.
How the discs are handled and stored can greatly affect their life period. There are many things that the user does that can shorten a disc’s life. Fingerprints and scratches are the most common. It is especially important that writable CDs not have fingerprints on them before they are written, as the fingerprint can scatter the laser beam from the recorder. In this case, the data can be jumbled or not be recorded at all which can result in an unusable disc.
Stickers should be used only with the greatest of care. Labels that are applied off-center or with air bubbles and creases can cause the disc to spin out-of-balance. This is especially harmful in high-speed recorders and readers. Removing a label can also damage the disc’s surface, rendering it useless.
It’s also important what format you back up your work since standards changes during time. Maybe a good if you want to save a multitrack is to save the tracks as separate wav files instead of session file.
66. What are 'virtual tracks'?
Soundcards provide real tracks whose number is dictated by hardware limitations, just like stand-alone recorders, but software can offer virtual tracks. Virtual tracks are streams of audio read from the hard drive and mixed with others by the audio sequencer, quite often emerging as just a single stereo pair of real tracks from hardware sockets during mixdown. All the mixing, as well as EQ manipulation and effects, is carried out internally by the PC processor. The huge difference between a hardware recorder and the virtual tracks used by a modern MIDI + Audio sequencer is that the sequencer doesn't have the same restrictions when it comes to adding more tracks. If your PC can manage 50 simultaneous tracks of audio playback you can write arrangement with up to arrangement with 100 tracks of different instruments, as long as you never exceed 50 tracks at any single moment.
In the domain of MIDI production virtual tracks refer to tracks that exist only in MIDI
67. What is meant by 'edit density'? What are the implications of high edit density?
Edit density is the amount of edits you have in your project and the most significant factor in track counts. If your edit density is to high you will get dropouts and timing problems caused by to much workload for the PCU and your hard drive.
When an audio file is recorded it is recorded in long contiguous sections on the disk. The disk does not have to work hard to retrieve the data therefore many tracks can be replayed simultaneously. When material is edited, then the regions that are to be replayed are probably not continuous on the disk, so the heads have to move more often to retrieve the data. Ultimately, there can come a point where this affects the number of simultaneous tracks. The term 'edit density' is used to mean the number of regions, their length and proximity to each other (shorter, more densely packed, regions make the disk work harder) and how far they are physically separated on the disk. The greater the edit density, the fewer tracks will play. If high edit density is causing a problem, two or more disks should be used so that tracks can be shared among them.
68. Does the editing and trimming of regions delete audio data from the disk?
When an audio file is recorded it is recorded in long contiguous sections on the disk. If you have a non–destructive edit system on your sequencer this file will be the same even if you’re are trimming and editing. It’s only the order how the contiguous file will be played back that changes.
69. In editing, what is the difference between 'slip' and 'grid' modes?
Slip and grid modes refer to how different regions or tracks can be moved in a sequencer. In slip mode the regions or track can be moved and dragged anywhere in the project. In grid mode the region or track will always snap to the grid that has been setup. The grid can be setup according time or note values.
70. When might it not be possible to create a crossfade?
To be able to create a crossfade there has to be audio on the disk that extends beyond the region boundaries. It is this material that is used to create the crossfade. If there is no material beyond the region boundaries, or insufficient for the desired duration of the crossfade, then the crossfade cannot be created.
71. What is 'bouncing', in the context of mixing?
The term 'bouncing' in multitrack recording can mean two things:
a) mixing together similar tracks, such as backing vocals, onto fewer tracks to free up the original tracks for further recording. This is only necessary if there are limited amount of tracks or if the recording system can’t handle more simultaneous tracks.
b) It can also mean save your mix since there no need to record a mix to a separate medium such as DAT or CD; it can simply be bounced to disk as a stereo file. In some systems, bouncing can take place faster than real time, although real time bouncing is better for the proper functioning of mix automation and plug-in effects, and real time bouncing offers the chance of listening to the mix, just to make sure that it is correct.
72. What is meant by 'latency'? What is the difference between DSP processing and host-based processing?
Latency means the delay that occurs between one event and another. In workstations latency normally means the delay between outputs and inputs of the audio hardware. Low latency is very important when using a workstation channels as foldback when overdubbing.
In a host-based processing system all calculations are done by the computer (CPU), all effects, processing, mixing etc. Audio signals are different in structure from standard computer data. This can give problems with latency and disk performance.
The alternative to host-based processing is DSP, or digital signal processing where using DSP chips specially designed for the purpose. Digidesign's Pro Tools, for example, uses DSP cards to perform mixing and plug-in effects. The latency of a DSP-based system is very low, of the order of 3 to 4 milliseconds. The cost of a DSP-based system is higher then a host-based system.
SOURCES
Audiocourses Software. Recording Engineer 2.0
DJ Source (Undated). Available: http://www.djsource.co.uk/tutorials/dj-equipment/the-turntable-a-dj-equipment-tutorial/.
Huber, D.M., & Runstein, R.E. (2005). Modern Recording Techniques, 6th ed. Focal Press: Burlington
Nordmark, A.(2004) Cubase SX3 Operation Manual- Music Creation and Production System. Steinberg:
Oswinski, B. (1999). The Mixing Engineer’s Handbook. Mix Books: Valejo.
Rumsey, F. (2004). Desktop Audio Technology: digital audio and MIDI principles. Focal Press:Oxford.
Wikipedia - The Free Encyclopedia (2005). Available: http://en.wikipedia.org/wiki/Tape_loop
http://www.audiomasterclass.com/units/body/10analogrecordingbody.html
http://www.dmxl.net/qdl/mtandrecordingqdl.html
http://www.minidisc.org/dat_archiving.html
http://www.dmxl.net/coursenotes/digitaltaperecording.html
http://www.midi-sequencer.com/technology_sound_digital%20recording_dash_maintenance.html
http://www.churchsoundcheck.com/tra.html |
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Sun Oct 30, 2005 6:48 pm |
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Joined: 12 Apr 2005
Posts: 10
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1. Describe the following equipment used by a DJ: Cartridge and stylus, Pickup arm, Turntables, Mixer.
ANSWER: cartrige : the head of the arm where the niddle fitts in to . styles : the niddle . pickup arm : arm that lys the record , that in info goes thue . turntable : the deck its self , wat the record goes on to . mixer : for mixing 2 record players together
2. Why cannot the output of the cartridge be connected directly to a mixing console?
ANSWER:this can not be done becaused the line level from the cartridge will be to low . so the level has to be boosted the with use of a phono lead
3. Why is it convenient to DI a synthesizer?
ANSWER: to get the right line level for the mixing desk
4. Comment on the stereo output of many synthesizers?
ANSWER: ther are used for effects . the left output is mono
5. Why might it be desirable to amplify and mic up a synthesizer, as you would an electric guitar?
ANSWER: it would add tone and quility , and you would have more control of the sound because of the amps preamp
6. Comment on the use of loops in recording.
ANSWER: loops can be used for using the best part of a take as the bassist for a song . ie , a bass verse loop and a bass chours loop will give scrucher to the song for the overdubs
7. Comment on tape loops.
ANSWER:loops that are on pre recorded magnetic tape , are cut using the splice method and then stuck bacm together to create a repetitive musical pettern
8. Comment on looping using a sampler and sequencer.
ANSWER: a sampler is used to find the loop and to do any processinf required , ie pitch shift , time strech , start /end points , loop points . a sequencer is then used to trigger these samples
9. Why is the sample looped using the sequencer in preference to looping it in the sampler?
ANSWER: baecuse its the graphic interface thaat makes it easyer to loop basuse you can see where yoour start and end points are
10. Comment on the significance of synchronizing the sequencer to multitrack tape.
ANSWER: so that everything plays in time ans can be changed in squences
11. Comment on the suitability of audio sequencers for sample looping.
ANSWER: audio sequencers are vey suitabil for sample looping , once the sound it recorded , you can cut it up to fing your perfect loop and then paste where ever you like . ie .acid
12. What is timecode?
ANSWER: time cod it striped along the side of a magnetic tape usely on the last track , so it you were using a 24 track tape the time cod would be sriped on the 24th track . time code is a digital code used to keep the tape and equipment synchronised , this is a form og metadata used to identify a specific point on the tape , the standered time code is SMPTE
13. Comment on LTC, VITC and MTC.
ANSWER: LTC : longatudenal time code - it increases signal on to an audio track as a square wave . VITC: vertical interval time code - this encodes the information int he video signal , it is used on magnetic tape for broadcast and production use . MTC : midi time code - midi time code is used to keep everything in time , it traslats SMPTE thru a midi chain
14. Comment on MIDI Clock.
ANSWER: is how midi converts . a message send to all devices in midi system at rate of 24 times per quarto note ( 24ppq)
15. Why is it desirable to synchronize two MIDI units via MIDI Clock?
ANSWER:becuse it keeps it in time better
16. How does MTC correspond to MIDI Clocks and Song Position Pointers?
ANSWER: it corisponds by keeping tempo to the meter and and goes abck to the start and finish of the song
17. Why is it desirable to synchronize a sequencer to multitrack tape?
ANSWER: so that evrything would play in time with the loops
18. Comment on the two stages of building up a recording on multitrack tape with the aid of a sequencer.
ANSWER: thing is send time code so its all linked , pepare loops and record loops in to multi track tape
19. What is an audio sequencer?
ANSWER:a program that allows you to record audio and edit it and play it back . recording audio in sequnces
20. Is an audio sequencer suitable as a replacement for a multitrack tape recorder (analog or digital)?
ANSWER: yes , with the processinf powere available now a days by the rise of protools , cubase , etc
21. Comment on the suitability of an audio sequencer for sample and loop editing?
ANSWER: some audio sequencers (eg, acid) are based on loop editing where as others are just playing the samples , both are aquiley in depth and suitable
22. Why is it not straightforward to synchronize an audio sequencer to multitrack tape?
ANSWER: they both use diffrent time code , tape uses LTC . sequncer uses MTC . to have the tape as a slave , expersive hardware will have to be used as the tape machines speed regulator must be connected to a control loop
23. What parameters of effects can often be controlled via MIDI?
ANSWER: 127 diffrent parameters can be controlled via midi , general purpose content , filltter , pan , volume , tempo , phaser , chours , etc
24. Why would you want to control effects parameters by MIDI?
ANSWER: you would want to control effects parameters by midi because it can control the effects more acquitetly ans in sync with the song
25. Does MTC come in all the frame rates of SMPTE/EBU timecode?
ASNWER: MTC only comes in 24 , 25 or 30 frame rates . it locks to each one
26. Does MTC contain an address?
ANSWER: yea MTC conrains address information
27. Does MTC contain a clock?
ANSWER: no it does it . MTC contants address and sync acording to these address
28. Is MTC useful for synchronizing a MIDI sequencer?
ANSWER: yes this can be done
29. Is MTC useful for synchronizing digital audio?
ANSWER: yea beacuse it keeps everything in time
30. Is MTC useful for synchronizing analogue audio?
ANSWER: no MTC is a digital message which can not be used to sync udio like a multi track tape
31. Comment on the difference between standalone hard disk recorders and computer based hard disk recorders.
ANSWER: computer based hard disk recorders have a graphic interface thats why computers are becoming more popular for recording , allso because being able to see and hear the wave makes it at lot easyer to edit
32. Why is it a problem to use hard disks for long term storage?
ANSWER: this is a problem because information might be lost true acsadent or movement
33. Onto what media does backup/archival storage take place?
ANSWER: cd or dvd are the most comman
34. What are the advantages of standalone hard disk recorders (compared to tape) for editing?
ANSWER: stantalone hard disk recorders use non distrucktive editing method , with tape recorders if a mistake is made can not be rectafided
35. What are the advantages and disadvantages of computer based hard disk recorders compared to standalone hard disk recorders?
ANSWER: the advantages of a computer based hard disk recoder would be that it has a graphic interface and that you can see and liten to the wave at the same time ,a computer also has more memory , disadvantages would be that a computer is not just built for recording , it has other programs on it , such as word processers , games , internet ,etc . this might cause the computer to crash resulting it the lose of data
36. Comment on the use of Pro Tools as an accessory to multitrack tape.
ANSWER: the data on multi track tape can to ransfered to pro tools which it can be edited and mixed on rather that using a dirtucktive method to edit the tape
37. List the common digital multitrack tape formats and describe their characteristics.
ANSWER: DAT (digital Audio Tape)4mm magnetic tape Offering sample rates of 32/44.1/48KHz with 16-bit quantization
, ADAT(Alesis Digital Audio Tape) Uses S VHS video tape offering 8 tracks of 16/20-bit audio recorded at 44.1KH
, DASH (Digital Audio Stationary Head) Uses ½ inch tape offering 2 to 48 tracks to be recorded Sample frequencies of 44.1, 48KHz are available with up to 24-bit sample rate
DTRS (Digital Tape Recording System) Uses a Hi8 cassette format offering 8 tracks of 16/24-bit audio recorded at 44.1/48KHz
38. What is 'formatting'?
ANSWER: fromating is preparing the tape for a priticular use , preparing midi for use to play on a record system
39. What are the advantages and disadvantages of digital multitrack compared to analogue multitrack?
ANSWER: advantages : non distrucktive edits , vertial tracks , subjectively better sound , quility . disadvantages : lack of anolog warmth
40. Compare the maintenance and cleaning of an analogue recorder to that of a digital recorder?
ANSWER: clean heads after every session , demagnitise heads . digital reocders do not need to be cleaned , make sure dives have space and back ups are doin regulary
41. Who carries out routine maintenance?
ANSWER: the engineer
42. Describe how the heads and guides of an analogue machine are cleaned. Mention the materials used.
ANSWER: to clean the heads and guides of an analogue machine you wold use d-natured alcohol or isoproprl alcohol , a magitic head degauser is allso used
43. Describe how the pinch roller of an analogue machine is cleaned. Mention the materials used.
ANSWER: first remove the lid and find the pinch roller, the move it , wash under tape with washing up liquid , ( isoproprl alcohol can erode the rubber). then play tape with lip on to check that the tape is being pulled correctly
44. What are the effects of neglecting cleaning?
ANSWER: quiltity decreases in reocrds made to tape bacause of oxoid shed , if this builts up on the heads this means that there is a bit of seperation
45. Why must an analogue machine be periodically demagnetised?
ANSWER: this must be donw because a built of of magnetisim o nthe head can lead to posible loss of high frequneces on tape . an analogue machine should be demagnitised after 10 hours of operartion
46. What happens if a machine is never demagnetised?
ANSWER: causes high frequnces on tape to be lost
47. What might happen if the demagnetised is operated incorrectly?
ANSWER: some of the sound on the tape will apear missing , so all of the audio will not be hear , this can get worse over if the machine is still not demagnetised
48. Why do analogue tape recorders need to be lined up?
ANSWER: they need to be lined up because there is diffrent heads . if the heads are not alined properly the tape heads will wear out . set up hige of head . if a track is recorded and reproduced on heads with diffrent hights all the signal will not be reproduced . results in increase talk between multi track channels
49. Do digital recorders ever need to be lined up?
ANSWER: no
50. Comment on the three elements of line up.
ANSWER: high : where the tracks vertical positions will be along the with of the magnetic tape. azimuth : refers to tilt of the head in the plain paralel to the tape. zenith : the tilt of the head tawards or away from the tape , bottom and top should have pressure
51. Explain the need for monitoring in sync.
ANSWER: to prefrom correctly when recording you need to be able to listen back with no delay
52. Why is the sync signal inferior to the playback signal?
ANSWER:
53. Why does this matter in track bouncing?
ANSWER:
54. Is it possible to edit 2" analogue tape?
ANSWER: no
55. Is it possible to synchronise two 24-track recorders?
ANSWER: yes
56. Why is it often considered better to use an integrated disk recording system rather than one that uses a personal computer as the user interface?
ANSWER: it is concidered better because an intergrated hard disk recording system bacuase a hard disk recorder is just built fo recording , it has no other purpose , only to record and play back . a computer has lots of other programs , like word processers , games , the internet , etc , which could result in the computer crashing and the lose of data
57. Comment on the presentation of some disk recorders as replacements for tape multitrack recorders.
ANSWER:
58. If a tape recorder has 24 inputs and 24 outputs, how many tracks will it have?
ANSWER: 24
59. How many inputs and outputs would a disk recorder need if it was to be a replacement for a 24-track tape recorder?
ANSWER: 24 , ins and outs . in can have a little as 4 if not similtanies recording , if similtanies it need s 24 ins and outs
60. If a disk recording system had two inputs, two outputs, and was capable of twenty-four tracks, what would be its main limitations?
ANSWER: its main limitions would be that it can olny send in sterio signal and that it can only record 2 tracks at once
61. What information is stored in the session file?
ANSWER: session file stores all your recording information , like sound files , effects , processing done . these files can be found on a computer , or an intergrated hard disk recorder
62. Are session files usually transportable between different systems?
ANSWER: yes they are
63. Comment briefly on the suitability of SCSI, ATA and Firewire disks for audio recording.
ANSWER:
64. What is 'fragmentation'?
ANSWER: fragmention is when the files on your computer get stored in more that one location on the computer from lots of use , there fore your computer will get cloged up , so that is why we defragment
65. Comment on archiving to CD-ROM.
ANSWER: archiving to cd- rom is backing up your computers data to the a cd- rom , to free the computers space or to keep the information safe incase your computer crashes . archiving to dvd-rom is allso commanly used because dvd-rom's can hold a lot more memory
66. What are 'virtual tracks'?
ANSWER: virtual tracks are tracks in tracks . for example , if you had a digital 8 track recording system , each of the 8 tracks on the recording system will have its own 8 tracks built in to it , so each of the 8 tracks contans its 8 vitral tracks . so alltogether you will have 64 tracks but you can only play 8 tracks back at once
67. What is meant by 'edit density'? What are the implications of high edit density?
ANSWER: the amount of editing done in editing a song is messered in edit density
68. Does the editing and trimming of regions delete audio data from the disk?
ANSWER: no it only changes it for the arrangment
69. In editing, what is the difference between 'slip' and 'grid' modes?
ANSWER : slip mode is where you can move the the piece of audio work around where ever you want , grid mode is where it will snap to the gris or beat or second etc , so in grid mode you can move the piece of audio where ever you want
70. When might it not be possible to create a crossfade?
ANSWER: if the 2 tracks you wish to cross fade to not over lap
71. What is 'bouncing', in the context of mixing?
ANSWER: bounching is for example you you were mixing say 6 drum tracks , if you where happy with there level and sound you could bouch the 6 drum tracks to 1 seperate track , and you would be able to free up some of the tracks
72. What is meant by 'latency'? What is the difference between DSP processing and host-based processing?
ANSWER: latency is like a delay , eg . if a midi keybaord is connected to a computer and the keys on the keyboard are triggering a soft synth , the time it takes from when you press the key on the keyboard untill your ears can hear in is latency , how long it take for your ears to hear it |
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