AUdIoCoUrSeS
Joined: 31 Oct 2002
Posts: 2014
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| Week 6 - Equipment 3 |
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Hi all.
Here are your questions. Not quite so many this week as I want you all to have a good crack at the practical task this week, which should take some time if you do it correctly! Answer all questions this week.
I'm looking for short answers again though slightly more expanded than last week.
Links to help: (I've not read all of these in detail so use your own judgement)
http://www.ultimate-guitar.com/column/396.htm
http://www.dorrough.com/About_Us/Dorrough_Vision/dorrough_vision.html
http://www.sospubs.co.uk/sos/jan00/articles/mix.htm
http://www.dolby.com/company/is.ot.0009.History.02.html
http://lmbpc.lincoln.ac.uk/audio/noise.htm
1. What is the function of automation?
2. Why would faders have to be moved during the mix?
3. What aspects of mixing are normally automated on an analogue console?
4. Comment on VCA vs. Moving Fader automation.
5. Describe write/update/read.
6. How does an automated mix session start?
8. How would a section of automation data be re-recorded?
9. How are automation 'punch-ins' blended smoothly with existing data?
10. How could a complex series of moves be increased in level by say 3dB?
11. Describe fader grouping.
12. How could EQ, for instance, be automated using an analogue mixing console?
14. How would EQ be automated using a digital mixing console?
15. What is 'recall'?
16. Why is recall necessary?
17. What advantages does a digital console have over an analogue console regarding recall?
18. Describe how you would use a compressor with a side chain input as a de-esser.
19. Describe how you could use a two-channel compressor with a stereo link switch as a de-esser without using the side chain inputs.
20. Explain why a noise gate would not be used when recording Scottish bagpipes.
21. What noise is often heard from an orchestral harp, besides the sound of the strings?
22. Describe how you would use a noise gate to impose a rhythm onto a sustained synth string sound.
23. Describe why the two channels of a stereo compressor must be linked when processing a stereo signal.
24. When mixing a popular music recording using an automated console. If the console is neither digital nor digitally controlled analogue, what facilities would you expect to be able to automate? 25. Often a multitrack recording contains unwanted sounds when instruments are not meant to be playing. State how this can be rectified.
26. On a VCA automated mixing console a number of level changes have been made to the vocal. The producer wishes to keep these changes but increase theoverall vocal level by 3dB. Explain how this is achieved. 27. Is it possible to have an automation system which has moving faders yet the gain is altered by VCAs?
28. Describe the Decca tree system of miking.
29. Describe why `update' or `trim' mode is desirable in a mixing console automation system.
30. State the meaning of EACH of the following sets of initials
i) VU ii) PPM. Briefly describe the difference between VU and PPM meters.
31. With reference to an analogue multi-track recorder briefly explain a) the term `sync' output b) why the `sync' output is required when overdubbing.
32. Describe how a noise gate can be used to create gated reverb on a snare drum, using two microphones and the natural reverberation of the studio.
33. Briefly explain, in terms of quality, the effect of mixing a signal with a version of the same signal delayed by 1 millisecond.
34. State the effect that would be achieved by continuously modulating the delay time up and down. In reference to question 33.
35. Comment on the use of walking surfaces in audio drama production.
36. Why is it not suitable to connect the output of a record player pickup cartridge directly to a studio mixing console? Give two reasons.
37. If it is desired to equalise or compress an entire stereo mix, to which inputs/outputs of the console should the equaliser or compressor be connected? Assume a fully specified mixing console.
38. Describe the function of the stereo link switch in a compressor.
39. What is VCA Grouping?
40. Explain flanging.
41. Exlain chorusing.
42. How can chorus be created with two tape machines.
43. Where does the term flanging come from?
44. What is noise reduction?
46. List some milestones in noise reduction technology.
47. Describe what is meant by plate reverb and spring reverb.
48. Explain the term "in-phase".
Good luck.
Last edited by AUdIoCoUrSeS on Mon Apr 07, 2003 10:53 am; edited 1 time in total |
Sun Jan 12, 2003 9:39 pm |
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Aidan
Joined: 08 Jan 2003
Posts: 38
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Chris
Question 7 doesnt make much sense to me-is it the answer to Question 6?
Also there appears to be no question at 13.
Regards
Aidan |
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Mon Apr 07, 2003 10:25 am |
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AUdIoCoUrSeS
Joined: 31 Oct 2002
Posts: 2014
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Aidan well spotted, didn't make much sense to me either. All edited now. No number 7 or 13.
Good luck.
Chrish |
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Mon Apr 07, 2003 10:54 am |
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resol69
Joined: 31 Dec 2002
Posts: 69
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| Nancy's thoughts |
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1. What is the function of automation?
Automation controls the functions on a console so the engineer does not have keep moving settings during playback.
2. Why would faders have to be moved during the mix?
To make one part louder at a certain part in the song, like during a guitar solo. You would turn up the guitar any possible turn down other instruments.
3. What aspects of mixing are normally automated on an analogue console?
Faders, fader grouping, panning.
4. Comment on VCA vs. Moving Fader automation.
Flying Fader: Faders are motorized and move during playback after automation has been recorded.
VCA (Voltage Controlled Amplifier): Volume is changed by changing the voltage going to the fader, but the fader does not move.
5. Describe write/update/read.
When you are in write mode you are recording automation
In update mode you are changing automation that was previously recorded (only new info is recorded. If you don’t change a certain part, the old automation stays in place)
In read mode the automation is played back, you cannot write or update the automation.
6. How does an automated mix session start?
You would put the console automation is write mode and start the playback.
8. How would a section of automation data be re-recorded?
Put the console is write mode and re-record the automation during playback.
9. How are automation 'punch-ins' blended smoothly with existing data?
When you perform the punch-in, the fader has to be set to the same place as originally programmed - otherwise there will be a level jump at the punch-in point. Moving fader systems always keep the faders in the correct position for a punch-in because the fader position always determines the channel gain.
10. How could a complex series of moves be increased in level by say 3dB?
Group the faders together and use automation to increase the level of the group.
11. Describe fader grouping.
A number of faders are assigned to a group, the entire group is then controlled by one fader.
12. How could EQ, for instance, be automated using an analogue mixing console?
You can bounce the instrument to different tracks, set the different EQ settings you need and mute the tracks during the song when they are not in use. So you’d have say 2 or 3 tracks of the same instrument and turn them on and off using the mute button during the song. This uses up valuable tracks, though.
14. How would EQ be automated using a digital mixing console?
You could write the automation during playback or use presets.
15. What is 'recall'?
Recall is the process where the automation brings up the settings that you stored earlier.
16. Why is recall necessary?
You need to store the automation settings so the console knows what changes to make.
17. What advantages does a digital console have over an analogue console regarding recall?
You can store more settings on different functions and switches on a digital console. They can be totally automated, including the patch bay. On an analogue console, you’ll need to write down your settings for functions that are not automated, or take a photo of them, to bring up the same mix.
18. Describe how you would use a compressor with a side chain input as a de-esser.
You need to isolate the bad part of your signal to send into the side-chain, you need to first split your main signal. You can use patch bay if you have one or use a splitter cable. Often the best place to split the signal is directly from the tape machine. If you have a digital studio then you'll need to get the signal post converter. Once you split your signal then you need to send that to the parametric EQ. This will allow you to isolate and boost the nasty part of your signal to send into the side-chain. The output of the EQ then goes into the side-chain input on the compressor and dead ends there. The other split of your main signal goes into the main input of the compressor.
To pinpoint the nasty S sound you need to listen to what's going into the side-chain. You can do this two ways: If your compressor has a "side-chain listen" button you can switch the side-chain input to the main output and hear exactly what's going on. Otherwise you need to temporarily plug the EQ's output into a free channel on your console and listen that way. Once you can hear the side-chain you can then narrow the frequency band with the Q control, then boost the signal and use the frequency control to narrow in on the tone. Once this is accomplished you can boost this narrow band more and the compressor will react to that sound first.
19. Describe how you could use a two-channel compressor with a stereo link switch as a de-esser without using the side chain inputs.
You could use one channel for compression, the second channel for de-essing and use the stereo link to ensure that both channels have the same output level. (? Guessing here.)
20. Explain why a noise gate would not be used when recording Scottish bagpipes.
There is rarely silence coming from the bagpipes, you need silence for a noise gate to work.
21. What noise is often heard from an orchestral harp, besides the sound of the strings?
The sound of the fingers plucking or strumming the strings.
22. Describe how you would use a noise gate to impose a rhythm onto a sustained synth string sound
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You could use the external key function. Put the sustained signal through the gate, and then use the external key to chop it up into a rhythm. Like this:
Connect a drum machine, or other rhythmic source synchronized to the track, to the external key input.
Switch the gate to external key.
Set the threshold so that the gate triggers on a signal from the external key.
Adjust the attack, hold and release controls to achieve the desired envelope to create a rhythm.
23. Describe why the two channels of a stereo compressor must be linked when processing a stereo signal.
The stereo link has to be activated so that both channels provide the same amount of gain reduction. If this is not done, a loud signal in one channel will cause that channel to be lowered in level while the other stays the same. Any signal that is panned center in the mix will swing in the stereo image towards the unaltered channel. With stereo link selected, the stereo image is maintained.
24. When mixing a popular music recording using an automated console. If the console is neither digital nor digitally controlled analogue, what facilities would you expect to be able to automate?
Faders and panning.
25. Often a multitrack recording contains unwanted sounds when instruments are not meant to be playing. State how this can be rectified.
You could try some EQ, or use a noise gate on that track.
26. On a VCA automated mixing console a number of level changes have been made to the vocal. The producer wishes to keep these changes but increase the overall vocal level by 3dB. Explain how this is achieved.
You could make the changes, them bounce to another track, raise the new track level by 3dB. All the original changes in level will be there.
27. Is it possible to have an automation system which has moving faders yet the gain is altered by VCAs?
Yes the console could have VCA fader grouping. On a console with VCA grouping, all the channel faders have a small switch that can select one of (usually) eight VCA masters. When a VCA master is selected, that controls the overall level of all channels set to that group. So, the level of the those faders is controlled by one fader. With conventional subgrouping, the audio is mixed through the group fader(s). With VCA grouping, the VCA fader simply sends out a control voltage to the channel faders.
28. Describe the Decca tree system of miking.
A triangle of microphones is placed roughly ten to twelve feet above the stage level, just behind the conductor. There are usually two additional flanking microphones used as well, anywhere from either edge of the orchestra, to about one third of the hall's width in. Spacing of the three mikes themselves, this varies with the venue used and with the size of the ensemble. (soloists are spot-miked).The mixer is adjusted so that the center mike goes equally to both channels of a two track recorder, with the right tree mike and right outrigger going to the right channel, and both left mikes to the left.
29. Describe why `update' or `trim' mode is desirable in a mixing console automation system.
So you don’t have to re-record all of your automation, you can just update the automation you already have.
30. State the meaning of EACH of the following sets of initials
i) VU ii) PPM. Briefly describe the difference between VU and PPM meters.
VU= Volume Unit, PPM =Peak Program Meters. Both display signal levels, however a VU meter displays the average volume level of an audio signal and PPM displays the peak volume level of an audio signal.
31. With reference to an analogue multi-track recorder briefly explain a) the term `sync' output b) why the `sync' output is required when overdubbing.
Sync means that the new tracks you are recording match up with the tracks already on the tape. Since the playback head is a few inches away from the record head, you would hear a delay if you didn’t have sync output on the machine.
32. Describe how a noise gate can be used to create gated reverb on a snare drum, using two microphones and the natural reverberation of the studio.
Put one mic on the snare and one a few feet away in the room. Add the noise gate to the room mic input.
33. Briefly explain, in terms of quality, the effect of mixing a signal with a version of the same signal delayed by 1 millisecond.
You ear won’t hear the delay, but when the signals are mixed, you’ll get phase cancellation or a comb filer as we discussed last week. The sound will sound hollow and spacey, like flanging.
34. State the effect that would be achieved by continuously modulating the delay time up and down. In reference to question 33.
I think this would make the sound pulsate, in a science fiction sort of way.
35. Comment on the use of walking surfaces in audio drama production.
Walking surfaces can be used to create sounds not picked up by on-stage mics. Say you have person walking across a room. If you put a mic on the floor to pick that up it may be too loud, or not sound right. Someone using a walking surface backstage with a mic can control the type and level of the sound, or continue to make the sound as the person walks off stage, so the audience hears the actor walking to and from the stage.
36. Why is it not suitable to connect the output of a record player pickup cartridge directly to a studio mixing console? Give two reasons.
You need to connect the player to a mic-pre-amp then have the pre-amp connected to a line input channel on the board. You need a pre-amp for two reasons:
1. The signal from such a cartridge is too low to record (typically <5mV for moving magnet, <0.5mV for moving coil) so must be boosted to about 100mV needed to drive line level inputs.
2. The signal is RIAA equalized (applied when the LP is mastered to get around mechanical limitations of the LP system) which must be reversed so as to provide a flat frequency response for the line input.
37. If it is desired to equalise or compress an entire stereo mix, to which inputs/outputs of the console should the equaliser or compressor be connected? Assume a fully specified mixing console.
You should connect the EQ or compressor to the consoles stereo bus sends and returns.
38. Describe the function of the stereo link switch in a compressor.
The stereo link has to be activated so that both channels provide the same amount of gain reduction. If this is not done, a loud signal in one channel will cause that channel to be lowered in level while the other stays the same. Any signal that is panned center in the mix wiill swing in the stereo image towards the unaltered channel. With stereo link selected, the stereo image is maintained.
39. What is VCA Grouping?
On a console with VCA grouping, all the channel faders have a small switch that can select one of (usually) eight VCA masters. When a VCA master is selected, that controls the overall level of all channels set to that group. So, the level of the those faders is controlled by one fader. With conventional subgrouping, the audio is mixed through the group fader(s). With VCA grouping, the VCA fader simply sends out a control voltage to the channel faders.
40. Explain flanging.
Flanging is mixing the signal with a copy of the same signal that’d delayed between 0-20 ms. This creates a hollow, spacey sounding effect.
41. Exlain chorusing.
Chorusing is used to ‘fatten’ a sound. The sound is delayed around 15-35 ms. The delay is repeated.
42. How can chorus be created with two tape machines.
Feed the signal into both machines. Send both to the same output, but start playback at different times.
43. Where does the term flanging come from?
Flanging gets its name from the way it was first produced. Playback was delayed by applying pressure to the flange of the supply wheel and “flanging” was born!
44. What is noise reduction?
Noise reduction is a means to get rid of tape hiss and other noise found in audio and video tape and film. To improve dynamic range and reduces noise, the signal must be processed before it is encoded on the tape and after it is decoded from the tape. This is called double-ended noise reduction. Noise reduction that occurs at only one end or the other is – you guessed it - single-ended noise reduction.
The most commonly used double-ended noise reduction systems are Dolby and dbx. We’ve seen Dolby on our home stereo equipment. Both Dolby and dbx can be readily seen in movie credits. The first systems were stereo, but they have now expanded into surround sound.
46. List some milestones in noise reduction technology.
1966: Dolby introduces Dolby A-type noise reduction. It used audio compression and expansion that dramatically reduced the background hiss inherent in professional tape recording without noticeable side effects on the material being recorded. Only one channel of noise reduction was provided.
1968: Dolby introduced Dolby B-type noise reduction, a consumer version. Like A-type NR, is a complementary compression/expansion system, requiring encoding when a recording is made, and decoding when the recording is played back. While Dolby produced A-Type NR, it licensed the consumer version to other production companies.
1960s Dolby starts researching how to use NR in films, The 364, the first Dolby cinema sound product, decoded mono optical soundtracks recorded with Dolby A-type NR does not come out until 1972. The out is mono.
1970: First consumer cassette decks with Dolby B appeared.
1970: Dolby began to promote the idea of releasing prerecorded cassettes encoded with the Dolby B-type characteristic, so that they would have low noise when played on players equipped with Dolby B-type noise reduction. Within a few years, virtually all prerecorded cassettes would be encoded with Dolby B-type NR, which remains true today. Dolby developed a trademark and quality-control license for record companies to use the Dolby trademarks on prerecorded tapes. To help establish Dolby B as the standard consumer tape noise reduction system and to promote sales of Dolby B equipped cassette recorders, the license was made royalty-free. This policy has remained in effect for all media recorded with Dolby technologies, which today encompasses not only virtually all audio cassette releases, but also thousands of videocassette, laser disc, video game, and DVD releases encoded with Dolby Surround and/or Dolby Digital.
1972: Still A-Type for professional use, but since multitracks were becoming popular, 16 channels of noise reduction were now possible from the same NR unit.
1973: Signetics' B-type IC made it far easier to incorporate Dolby B in consumer products . Each new Dolby consumer technology since has been made available to licensees in dedicated IC form.
1975: 1975: Dolby creates a highly practical 35 mm stereo optical release print format originally identified as Dolby Stereo for film.
1976: The CP50 sound processor provided cinemas a convenient, cost-effective means for decoding Dolby Stereo optical soundtracks .
1977, with the release of two immensely popular films that were recorded with the new Dolby technology: Star Wars and Close Encounters of the Third Kind. These blockbusters were exhibited in enough theatres that had the new Dolby equipment for audiences and industry alike to sit up and take notice.
Today: In addition to analog noise reduction and home theater surround sound technology, licensed technologies today include many digital technologies, such as Dolby Digital, the multichannel digital surround sound format adopted for use with DVD, digital broadcast TV, digital cable, and direct satellite broadcast (DSB).
1982 Dolby Surround encodes the two tracks of any stereo program source with four-channel surround sound, in much the same way as movie soundtracks.
1986 Dolby SR, the most powerful Dolby technology for analog recording, dramatically increased the dynamic range of such formats as film soundtracks and professional analog tape recording.
1987 Home theater, now enjoyed by millions of consumers worldwide, was made possible by the inclusion of four-channel Dolby Surround Pro Logic decoding in products such as A/V receivers .
1992 Dolby Digital (AC-3) is a multichannel digital audio coding technology first used for cinema sound (1992). Today it is also used to bring multichannel sound into the home via a wide variety of digital formats, including DVD, DTV, digital cable, and DBS.
Today:The Dolby Digital technology that makes it possible to place a multichannel digital soundtrack on 35 mm release prints also brings multichannel sound into the home via consumer digital formats.
47. Describe what is meant by plate reverb and spring reverb.
The plate reverb consists of a thin metal plate suspended in a sound proofed enclosure. A transducer similar to the motor of a moving coil loudspeaker drive unit is mounted on the plate to cause it to vibrate. Multiple reflections from the edges of the plates are detected by two (for stereo) microphone-like transducers. Reverb time is varied by a damping pad which can be pressed against the plate thus absorbing its energy more quickly. The plate would typically be mounted outside of the control room, with a remote control for reverberation time.
The spring reverb is an electromechanical device very much like the plate. Instead of a metal plate however it uses long springs in which the signal is allowed to vibrate and reflect. A good spring reverb can give a very good sound on strings, but is hopeless on anything percussive as the springs tend to twang. Spring reverbs are now hardly ever used.
48. Explain the term "in-phase".
In-phase means equipment is wired with the matching polarity. Sometimes phase is reversed purposely, like when you are trying to reduce leakage from mics that are near each other, or when creating effects. |
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Wed Apr 09, 2003 11:09 pm |
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Dani
Joined: 28 Jan 2003
Posts: 35
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1. What is the function of automation?
The function of automation is to reduce the number of things the engineer has to do at mixdown. It also lets the engineer be more accurate at the mix stage because a) They can take their time getting the mix right and any mistakes in level can be rectified. b) There can be more fader slides/mute's than would be possible with a single engineer at the desk.
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. Why would faders have to be moved during the mix?
Even with fantastic multiband compression, there are still quiet parts and loud parts of music. Faders would be moved, for instance, to raise the level of a vocal during the intro to a song, while it is being sung quietly and then lowered as the vocal becomes more powerfull. Or it can be raised to prevent being overpowered by the main thrust of music.
3. What aspects of mixing are normally automated on an analogue console?
It is mostly automated muting.
4. Comment on VCA vs. Moving Fader automation.
VCA's or Voltage Controlled can sometimes add noise to a system. Every VCA the signal passes through adds a little distortion. Moving Fader automation has the advantage of being visually correct, as in fader position/level output. Newer systems make the editing of fader changes extremely easy, with computer software that offers nonm destructive mix editing.
5. Describe write/update/read.
Write = record the automation data track. Update+ Make small changes to the data track. Read= Play the mix with the automation changes.
6. How does an automated mix session start?
By setting up the track faders in the best position for the mix, therefore you will have to make less fader moves to complete it. Then the tape is synced to the automation device. The mode used at this stage is "absoloute" mode.
8. How would a section of automation data be re-recorded?
You would overdob the mix settind like you wouls an audio track.
9. How are automation 'punch-ins' blended smoothly with existing data?
By using the software to "line up" the faders.
10. How could a complex series of moves be increased in level by say 3dB?
By using a sub group and adjusting the level of that rather than individual tracks.
11. Describe fader grouping.
The ability to set levels and move all faders using an allocated master fader.
12. How could EQ, for instance, be automated using an analogue mixing console?
By setting different eq's between two tracks and muting one at a time.
14. How would EQ be automated using a digital mixing console?
EQ can be automated by tweaking the pots and having the computer record the changes.
15. What is 'recall'?
Recall sets the faders to their origional position.
16. Why is recall necessary?
In case you need to re-set the desk. Or when a session is resumed.
17. What advantages does a digital console have over an analogue console regarding recall?
Digital desks can recall more settings, such as EQ, Pan and Fader.
18. Describe how you would use a compressor with a side chain input as a de-esser.
By using an EQ and boosting the offending frequiencies, this would in effect makew the compressor compress the high frequencies.
19. Describe how you could use a two-channel compressor with a stereo link switch as a de-esser without using the side chain inputs.
Route the high frequencies through one side and the nrmal signal from the other side and set the threshold on the offending frequencies lower. This would compress more when the offending frequencies were present.
20. Explain why a noise gate would not be used when recording Scottish bagpipes.
A noise gate would not be used to record bagpipes as they produce one long uninterupted tone with no gaps in between the signal.
21. What noise is often heard from an orchestral harp, besides the sound of the strings?
The sound of the "pluck".
22. Describe how you would use a noise gate to impose a rhythm onto a sustained synth string sound.
You could input a high hat track into the gate and set it only to open when the high hat nade a sound, this would then give a rythmic quality to the sound being gated.
23. Describe why the two channels of a stereo compressor must be linked when processing a stereo signal.
Because different levels on each side of the stereo field would affect the compressor differently.
24. When mixing a popular music recording using an automated console. If the console is neither digital nor digitally controlled analogue, what facilities would you expect to be able to automate?
Mute settings.
25. Often a multitrack recording contains unwanted sounds when instruments are not meant to be playing. State how this can be rectified
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You can either cut the waveform, if using a DAW, another method would be to use noise gates, you could also use automated mutes and as a last resort yo could pull the fader back.
26. On a VCA automated mixing console a number of level changes have been made to the vocal. The producer wishes to keep these changes but increase theoverall vocal level by 3dB. Explain how this is achieved.
By either using a sub group and upping the fader on that, or by upping the gain on a compressor.
27. Is it possible to have an automation system which has moving faders yet the gain is altered by VCAs?
You can combine Moving fader automation with systems that contain VCA's.
28. Describe the Decca tree system of miking.
The decca tree system uses a triangle of microphones. It was developed for recording classical music and opera in the 1960's.
29. Describe why `update' or `trim' mode is desirable in a mixing console automation system.
It can make minor subtle changes in levels, without affecting the automated faders.
30. State the meaning of EACH of the following sets of initials
i) VU ii) PPM. Briefly describe the difference between VU and PPM meters.
VU-Volume Unit meters come in the form of the Moving-coil Meter - the traditional 'needle' type of meter - or as a bar-graph of LEDs. They measure the average of the audio signal.
'PPM' - Peak Program Meters. A PPM displays the peak volume level of an audio signal.
31. With reference to an analogue multi-track recorder briefly explain a) the term `sync' output b) why the `sync' output is required when overdubbing.
a)sync refers to the syncronisation signal or "stripe" that tells external equipment such as sequencers or even another multitrack machines, where in time the tape is. SMTPE and Tape Sync (as on the wonderfull MMT- are two such syncronisation methods.
b) When using overdubs the sync track will make sure any synthesizers or drum machines will be heard by the performer.
32. Describe how a noise gate can be used to create gated reverb on a snare drum, using two microphones and the natural reverberation of the studio.
One mike is used near the drum to open the gate and the other is placed in the room and only lets sound through when the gate is triggered.
33. Briefly explain, in terms of quality, the effect of mixing a signal with a version of the same signal delayed by 1 millisecond.
This would cause phase problems and could even result in phase cancellation in some cases.
34. State the effect that would be achieved by continuously modulating the delay time up and down. In reference to question 33.
The signal would "flange" i.e. go in and out of phase.
35. Comment on the use of walking surfaces in audio drama production.
Walking surfaces are used in radio drama to simulate the actor/actress walking on different surfaces because a) they wouldn't be available in the studio and b) it would mean the actor would have to move off mic.
36. Why is it not suitable to connect the output of a record player pickup cartridge directly to a studio mixing console? Give two reasons.
Because the output of the deck would not be sufficient to register on the desk and because of RIAA equalisation. Since the RIAA correction boosts the bass frequencies (up to 20 dB)and reduces the treble frequencies, it is absolutely necessary the record your music at minus 20dB or else the low frequencies will be saturated and distorted.
37. If it is desired to equalise or compress an entire stereo mix, to which inputs/outputs of the console should the equaliser or compressor be connected? Assume a fully specified mixing console.
It should be connected to the Master Effects Bus.
38. Describe the function of the stereo link switch in a compressor.
The stereo link switch provides the facility to link the left and right channels of an output to prevent the compressor working at different
times.
39. What is VCA Grouping?
The simultaneous fade control over other faders by one master fader. It is a different approach to using sub groups.
40. Explain flanging.
Flanging is created by mixing a signal with a slightly delayed copy of itself, where the length of the delay is constantly changing.
41. Explain chorusing.
Chorusing occurs when a signal is delayed and played back onto itself, an LFO can be used to simulate a shimmering effect. It is a more complex version of "doubling". It is generally used to thicken a sound.
42. How can chorus be created with two tape machines.
Start one machine slightly before the other, this will not only double the sound but also because of phase differences will cause chorus.
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3. Where does the term flanging come from?
It comes from the way flange was origionaly produced using two tape recorders, where the secong tape was varied in speed by rubbing a finger on the "flange" or edge of the tape real.
44. What is noise reduction?
Noise reduction is the method of reducing tape his on analogue tape machines. Dolby NR and Yamaha's DBX are two such types.
46. List some milestones in noise reduction technology.
47. Describe what is meant by plate reverb and spring reverb.
Plate reverb had a small speaker on placed on a metal plate.
Spring reverb has an electric current passed through a coil.
48. Explain the term "in-phase".
Two periodic waves reaching peaks and going through zero at the same instant are said to be "in phase". |
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Thu Apr 10, 2003 3:35 pm |
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Aidan
Joined: 08 Jan 2003
Posts: 38
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1.What is the function of automation?
The function of automation is to have the ability to record and recall mix settings and to avoid using manual methods which are cumbersome and prone to error-one wrong move on a mix and you might have to start over again.
2.Why would faders have to be moved during the mix?
To adjust volume level of various signals to enable you place them in context,balance and position to give you the overall mix of sound required.
3.What aspects of mixing are normally automated on an analogue console?
Faders and fader grouping
4.Comment on VCA vs Moving Fader automation
These are two methods of memorising and controlling the gain of a channel-one method stores the position of the fader and uses this data to control the gain of a Voltage Controlled Amplifier,VCA.The other method also stores fader movements but uses the data to drive the faders position using a motor to move the fader.
5.Describe write/read/update.
In write mode you are recording the automation and in update mode you are changing or adding new data while keeping old data.In read mode you play back the automation.
6.How does an automated session start?
By setting faders to 0 and entering update mode.
8.How would a section of automated data be re-recorded?
You would go into update mode and make your changes referring to previous data and if happy you would confirm changes.
9.How are automations punch in blended smoothly with existing data.?
The faders will be kept in correct position -as they were when punch in required.Thus the punch in will be made into stored position.
10.How could a complex series of moves be increased by say 3Db?
Assemble the required faders into a fader group and then use one fader to increase level.
11.Describe fader grouping.
Instead of bussing signals to a pair of stereo busses to facilitate ease of mixing you could organise the channels into fader groups which are the moved with one fader.
12.How could Eq,for instance,be automated using an analogue mixing console?
By bouncing the signal to different tracks applying different Eq and then putting the track back into mix by muting.
14.How would EQ be automated using a digital console?
By using write or update mode to store settings.
15.What is recall?
This is where you bring back up previous settings used.
16.Why is recall necessary?
To enable you compare and make changes to settings.
17.What advantages does a digital console have over an analoge console regarding recall?
The digital system will generally have abilty to recall more settings than an analoge console.
18.Describe how you would use a compressor with a side chain input as a de-esser
A side chain allows a signal to be sent to an outside processor.The frequencies which are causing trouble,are sent to the processor which in this case would be an equaliser and the offending signals isolated by listening and a clean signal returned.
19.Describe how you would use a 2channel compressor with a stereo link switch as a de-esser without using side chain inputs.
I would imagine by using the 2 channels to isolate band requiring de-essing and putting that in say channel 1 and muting this signal.. The stereo link switch would be used to ensure signal is even to both channels.
20.Explain why a noise gate would not be used when recording Scottish bagpipes?
Bagpipes use a drone or constant air flow system, and there is never any pauses or breaks in sound thus the noise gate would not have a chance to be effective.
21.What noise is often heard from an orchestral harp besides sound of strings?
Possibly the clicking on nails on the strings which are generally steel.
22.Describe how you would use a noise gate to impose a rhythm onto a sustained synth string sound.
You would use the side chain or external key inputs to send the signal out to the gate to be chopped up by say a drum part sent to noise gate key.This key signal makes the gate open & close to the drum rhythm and when the two signals collide it chops the synth part into a rhythmic outpt.
23.Describe why the two channels of a stereo compressor must be linked when processing a stereo signal
The link switch allows the signal to be split equally between both channels thus ensuring that a loud signal in one channel will not cause that channel to lower more than other channel.
24.When mixing a popular music recording using an automated console.If the console is neither digital oir digitally controlled analogue what facilities would you expect to be able to automate?
Faders and fader grouping.
25.Often a mulititrack recording contains unwanted sounds when instruments are not meant to be playing.State how this can be rectified
Use a noise gate set to close off noise when no signal is present.
26.On a VCA automated mixing console a number of level changes have been made to the vocal.The producer wishes to keep these changes but increase overall vocal level by 3Db.Explain how this is achieved.
You colud make changes then bounce to another track and raise new track as required.
27.Is it possible to have an automation system which has moving faders yet the gain is altered by VCAs?
Possibly but Im afraid Im not sure how it works.
28Describe Decca tree system of miking
This method is used for orchestral recording with a trangle of mics placed ten feet or so from orchestra with the cetre mike going equally to both channels of a two track recorder and the right mic to right channel anf left mic to left channel.In addition two mics are placed left and right some distance into hall and fed to left and right of two track.
29.Describe why update or trim mode is desirable in a mixing console automation system
If you dont have update mode you will be unable to change or alter settings but instead will have to re record.
30.State the meaning of each of the following sets of initials:i) VU ii) PPM.Explain difference between VU and PPM meters. |
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Thu Apr 10, 2003 9:16 pm |
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Aidan
Joined: 08 Jan 2003
Posts: 38
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30.continued
VU is a Volume Unit meter usually a needle type meter and it measures the average volume levels while a PPM or Peak Program meter measures peak volume level.One measures the average while the other reflects peaks.
31.With reference to a multitrack recorder briefly explain a) the term sync output and b) why the sync output is required when overdubbing
Sync output in this case refers to the output taken from the record head of a multitrack recorder.On the Multitrack there are two heads :record and playback.They are spaced apart and therefore give rise to a slight delay.When overdubbing this slight delay would be noticeable if the playback head was used to monitor signal so a sync output is taken from the record head facilitating clean overdubs.
32.Describe how a noise gate can be used to create gated reverb on a snare drum,using two mics and the natural reverberation of the room
You would use two mics to mic snare drum up close and at end of room to capture reverberation.You would gate the mic capturing reverb and combine this with close mic of snare.
33.Briefly explain in terms of quality the effect of mixing a signal with a version of the same signal delayed by 1 millisecond
The delay is minimal and probably would bbe hard to pick up but it would colour the sound and give a slight flange effect.
34.State the effect that would be achieved by continuously modulating the delay time up and down-with reference to Q33
I think this would give a hollow sci-fi,Dr Who type of sound.
35.Comment on the use of wlalking surfaces in audio drama productions
I would imagine this is used to simulate the noise of actors walking as they couldnt move while recording/speaking their parts to mic.
36.Why is it not suitable to connect the output of a record player cartridge directly to a studio mixing console.Give two reasons.
Firstly because the output of a cartridge is too low and a pre gain would be required to get a decent signal and secondly because LPs are mastered using a RIAA equalisation process to overcome LP limitations and you would need to reverse the process to hear signal properly.
37.If it is desired to equalise or compress an entire stereo mix ,to which inputs/outputs of the console should the equaliser /compressor be connected?Assume a fully specified console.
The master Insert point.
38.Describe the function of the stereo link switch in a compressor.
This insures that the input to each channel is the same and that a loud signal in one channel will not effect or dragdown the level in that channel without having same effect in the other channel.
39.What is VCA grouping?
This is where one fader can take control of a group of specified faders using a Voltage controlled amplifier.
40.Explain flanging
This is where a signal is mixed with a delayed copy of the signal.Delay times will vary on level of effect required.Its not unlike the sound of a jet and can be wearying if overused.
41.Explain chorusing.
This is where a signal is delayed and played back onto itself.It gives a doubling effect which can fatten a sound.Its used to good effect on bass particularly fretless bass.
42.How can chourus be created with two tape machines
You could send signals to both machines and then send them back but delay slightly one signal.a
43.Where does the term flanging come from?
It was first produced on analogue tape machines by putting pressure on flange or outer core of the supply wheel in order to produce a delay.
44.What is noise reduction?
This is the means of reducing noise levels on tape analogue machines.
46.List some milestones in noise reduction.
Dolby was a company who pioneered the noise reduction process and introduced Dolby A in early 60s.This was their patented noise reduction system which worked by compression on tthe recorded sound and reveresed this on playback.It meant if the process was used on recording it had to be used on playback. This was superseded by Dolby B followed by Dolby Surround used in motion pictures and to Dolby SR which is the industry standard.Other systems developed by rivals are Dbx which is used on some multitrack tape machines.Again the use of these processes in recording meant they had to be used in playback.
47.Describe what is meant by plate reverb and spring reverb.
The plate reverb is a metal plate suspended in a hollow chamber with two pickups attached at each end to capture vibrations.Theses vibrations were started and controlled by a small motor and a damper used to vary times of reverb.The spring reverb works on same principle but springs used instead of metal plate.
48.Explain the term in phase.
When equipment is wired with same polarity it is said to be in phase.Also when two signals share the same wave length and pattern they are said to be in phase. |
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Fri Apr 11, 2003 9:06 pm |
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MIKE_NOSTRADAMUS
Joined: 08 Jan 2003
Posts: 163
Location: Northfork Recording Studios |
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Sorry about delay!!!the net a wonderful thing when it works!!!
this week it did'nt work so well.I got all kinds of funny stuff and garbage coming from all over.lucky my virus scanner caught all.
1. What is the function of automation?
The function of automation is to make things simpler for the engineer’s recording.
2. Why would faders have to be moved during the mix?
To make the complete mix sound better and to make certain tracks sound louderor softer.
3. What aspects of mixing are normally automated on an analogue console?
Faders and subgroup faders and pan .
4. Comment on VCA vs. Moving Fader automation.
5. Describe write/update/read.
6. How does an automated mix session start?
By the setting the track faders in the best position for the mix.
8. How would a section of automation data be re-recorded?
Put the console in write mode and re-record the automation during playback.
9. How are automation 'punch-ins' blended smoothly with existing data?
10. How could a complex series of moves be increased in level by say 3dB?
Use your subgroups and use the group single fader to increase the level of the group.
11. Describe fader grouping.
You assign a group of faders together and the group is then controlled by a single fader.
12. How could EQ, for instance, be automated using an analogue mixing console?
14. How would EQ be automated using a digital mixing console?
15. What is 'recall'?
Recall is when automation brings up settings that you stored earlier.
16. Why is recall necessary?
In case you need to reset.
17. What advantages does a digital console have over an analogue console regarding recall?
Digital can store more settings
18. Describe how you would use a compressor with a side chain input as a de-esser.
19. Describe how you could use a two-channel compressor with a stereo link switch as a de-esser without using the side chain inputs.
20. Explain why a noise gate would not be used when recording Scottish bagpipes.
I cannot see the need for expansion in dynamics for bagpipes. There is not much of a range.
21. What noise is often heard from an orchestral harp, besides the sound of the strings?
The sound of the fingers and nails, also the back of the nails.
22. Describe how you would use a noise gate to impose a rhythm onto a sustained synth string sound.
23. Describe why the two channels of a stereo compressor must be linked when processing a stereo signal.
You want both channels to have the same amount of gain reduction
24. When mixing a popular music recording using an automated console. If the console is neither digital nor digitally controlled analogue, what facilities would you expect to be able to automate?
Faders and panning and groups of mixed faders
25. Often a multitrack recording contains unwanted sounds when instruments are not meant to be playing. State how this can be rectified.
.
26. On a VCA automated mixing console a number of level changes have been made to the vocal. The producer wishes to keep these changes but increase theoverall vocal level by 3dB. Explain how this is achieved.
27. Is it possible to have an automation system which has moving faders yet the gain is altered by VCAs?
28. Describe the Decca tree system of miking.
It’s a system that uses three microphones in a triangle and each session is a different mixture and positioning of the microphones.
29. Describe why `update' or `trim' mode is desirable in a mixing console automation system.
30. State the meaning of EACH of the following sets of initials
i) VU ii) PPM. Briefly describe the difference between VU and PPM meters.
VU = Volume Unit These are possibly needle meters
PPM = Peak Program Meters These are possibly LED meters
31. With reference to an analogue multi-track recorder briefly explain a) the term `sync' output b) why the `sync' output is required when overdubbing.
a) sync means
32. Describe how a noise gate can be used to create gated reverb on a snare drum, using two microphones and the natural reverberation of the studio.
Put one mike on the snare and the other in the room. Add noise gate to the room mike.
33. Briefly explain, in terms of quality, the effect of mixing a signal with a version of the same signal delayed by 1 millisecond.
34. State the effect that would be achieved by continuously modulating the delay time up and down. In reference to question 33.
This could possibly make the sound pump. Amplitude going up and down.
35. Comment on the use of walking surfaces in audio drama production.
Walking surfaces would be sounds created back stage related to what is happening on stage.
36. Why is it not suitable to connect the output of a record player pickup cartridge directly to a studio mixing console? Give two reasons.
First of all you would need a pre-amp for the pickup cartridge to match the impedence of the mixing desk
37. If it is desired to equalise or compress an entire stereo mix, to which inputs/outputs of the console should the equaliser or compressor be connected? Assume a fully specified mixing console.
Connect the equalizer or the compressor to the mixing desk stereo bus sends and returns.
38. Describe the function of the stereo link switch in a compressor.
The stereo link has to be activated so that both channels provide the same amount of gain reduction.
39. What is VCA Grouping?
40. Explain flanging.
41. Exlain chorusing.
42. How can chorus be created with two tape machines.
You need a signal introduced into both machines. Once recorded start playback at different delayed times.
43. Where does the term flanging come from?
44. What is noise reduction?
Noise reduction comes in many forms. It’s the high end hiss on tape and other noises found on audio and video tape. Some noise reduction is made for vinyl disc ie: 222 dbx encoded albums. Noise reduction systems are dolby,dbx,jvc,anrs.
46. List some milestones in noise reduction technology.
Dolby, dbx, jvc, anrs, Dolby A, Dolby B and Dolby Surround Sound. Dolby seems to be the company that has achieved the most in noise reduction.
47. Describe what is meant by plate reverb and spring reverb.
I’ve never seen one but I understand it is a metal plate with a loudspeaker. The spring reverb is a bunch of springs interlocked with an electronic circuit used quite extensively in the sixties and seventies.
48. Explain the term "in-phase".
To me it means positives match positives and negatives match negatives ie: speakers
Another way of explaining is the output polarity would match the input polarity. |
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Sat Apr 12, 2003 1:50 am |
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