Spill (audio)
Spill (also known as bleed
Occurrence
Spill occurs when sound is detected by a microphone not intended to pick it up (for example, the vocals being detected by the microphone for the guitar).
Spill can also introduce sounds which are not desired as part of the recording or live sound mix, such as the sound of a squeaking piano pedal, the clacking of keys on a bassoon, or the rustling of papers on a public speaker's podium.
Spill is sometimes accepted or even desirable, particularly in
This is also true for drum recording and productions that need a "live" feel.[5][8] Whereas pop songs are often recorded one track at a time, for jazz and blues and other improvisation-based music, it is often desirable to have the band perform together, because this creates a better "feel" and more "swing", and because the musicians typically "feed" off each other's ideas in real time. For example, in a jazz tune, the "comping" musicians will alter their improvised accompaniment in response to the solo lines played by the saxophone player; as well, in some cases, the comping musicians will introduce melodic or rhythmic ideas which are picked up by the solo improviser.
In Jamaican reggae and dub, mic bleed is purposely used in recordings.[9]
Spill is often experienced with vocal recording, when the accompaniment is monitored through speakers or open-backed headphones.[10] It may also be a problem in studios without talkback facilities.[11]
Avoiding spill
Recording engineers and live sound engineers aim to avoid spill by:
- Placing microphones closer to the sound source[12]
- Using acoustic barriers (known as gobos);[12] for live sound, plexiglass screens are sometimes used for drums and brass.
- Reducing sound reflection in the recording room (e.g., by draping blankets on walls and windows)
- Having the different instruments and amplifiers set up in different isolation booths or rooms (particularly with loud electric guitar amplifiers)
- Recording every instrument and vocal one at a time using a multi-track recordingsystem.
- Using directional microphones[12]
- Maximising the distance between sound sources[12]
- Using DI units rather than microphones[13]
- Using piezoelectric pickups (e.g., with an upright bass)
- For vocalists, using closed shell headphones
- Cutting frequencies with an equalizer that are not present in the intended microphones's instrument or vocals (e.g., for a bass drum mic, all of the high frequencies could safely be cut; for a piccolo, all of the bass frequencies could be cut)
- Align tracks whenever possible, taking into account that there is audio sources more pollutants than others. For that, it is better to use a plug-in tool for "finding similarities and time differences".
Spill is also avoided by using a 3:1 distance rule of thumb,[14] which states that for each unit of distance between a sound source and its microphone, other microphones should be placed at least three times as far.[12]
Other methods of minimising spill include the use of noise gates.[8]
Examples
Spill is evident on
The effect can also be observed when operating a
See also
Footnotes
- ^ Senior (2009)
- ^ a b Huber (2005, p. 139)
- ^ Nisbett (2003, p. 373)
- ^ a b Eargle (2005, p. 303)
- ^ a b Robjohns (2004)
- ^ “Orchestral Recording Techniques’ by Christopher L. Stone. Available online at http://cdn.audioimpressions.com/OrchestralRecordingTechniques_R4.pdf Accessed on April 29, 2011.
- ^ "NAMM: Divide and Conquer with DVZ for "That Film Score Sound"". createdigitalmusic.com. Archived from the original on 2010-12-25.
- ^ a b White (2007)
- ^ Michael E. Veal. Dub: soundscapes and shattered songs in Jamaican reggae.Wesleyan University Press, 2007. p.74
- ^ Recording Microphones (2010)
- ^ Brice (2001, p. 355)
- ^ a b c d e Huber (2005, p. 140)
- ^ Crich (2005, p. 36)
- ^ Wellington College (2011)
- ^ a b Lewisohn (1989, p. 60)
- ^ a b McKinney (2007)
Sources
- Brice, Richard (2001), Music Engineering, Oxford: Newnes, ISBN 0-7506-5040-0
- Crich, Tim (2005), Recording tips for engineers: for cleaner, brighter tracks, Kidlington, Oxfordshire: Focal Press, ISBN 0-240-51974-4
- ISBN 0-387-28470-2
- Huber, David Miles (2005), Modern Recording Techniques (6th ed.), Kidlington, Oxfordshire: Focal Press, ISBN 0-240-80625-5
- Lewisohn, Mark (1989), The Beatles Recording Sessions, New York, NY: Harmony, ISBN 0-517-57066-1
- Nisbett, Alec (2003), The Sound Studio: Audio Techniques for Radio, Television, Film and Recording, Kidlington, Oxfordshire: Focal Press, ISBN 0-240-51911-6
- Recording Microphones (2010), Achieving Good Lead Vocal Recordings, Nottingham, Nottinghamshire: Recording Microphone, retrieved 12 April 2011
- McKinney, Des (2007), 10 Recording Bloopers That Made the Album, Toronto: Hometracked, retrieved 12 April 2011
- Robjohns, Hugh (2004), "Q. Can I use acoustic screens to effectively prevent drum spill?", Sound on Sound, Cambridge: SOS Publications, retrieved 12 April 2011
- Senior, Mike (2009), "Q. What is the best way to reduce bleed on a drum recording?", Sound on Sound, Cambridge: SOS Publications, retrieved 12 April 2011
- Wellington College (2011), Close-Mic Techniques, Crowthorne, Berkshire: Wellington College, retrieved 12 April 2011
- White, Paul (2007), "Recording Loud Bands In The Studio", Sound on Sound, Cambridge: SOS Publications, retrieved 12 April 2011