Microphone Placement

Rules of Microphone Placement

• There are no rules, only guidelines - use your ears!!

• The overall sound of an audio signal is no better than the weakest link in the signal chain.

The GOOD RuleGOOD Musician +

GOOD instrument +

GOOD performance +

GOOD acoustics +

GOOD microphone +

GOOD placement =

GOOD SOUND!!

Stating the Obvious• Make sure you know where the front of the mic is (usually the makers logo)

• Make sure it is the right type of mic for the job.

• Don’t place the mic so that it annoys the musician as they play.

• Make sure the musician isn’t going to hit the mic.

• Keep the mic leads tidy.

• Hand tighten the mic stand.

Close Mic’ing• Helps to avoid ‘leakage’ from other instruments. More separation.

• Gives a ‘tight’, clear, direct sound.

• Less feedback in live situations.

• Excludes the acoustic space.

• The recording can be easily edited to simulate different acoustic environments.

• Don’t record TOO close - most instruments need some space for the sound to develop.

Distant Mic’ing• It can pick up a large portion of a musical instrument or ensemble, whilst

preserving the overall tone balance.

• “Live” feel.

• Allows the room’s acoustics to ‘colour’ the direct sound signal.

• Often used with large orchestral ensembles.

• Can’t do overdubs.

• Distant mic’ing = about 1 metre or more from the sound source.

Inverse Square Law• Sound that is radiated from a point source drops

in level at 6dB per doubling of distance.

• Ie the further from the sound, the less the volume.

Ambient Micing• Mic’s placed at such a distance that the room acoustics are more

prominent than the ‘direct’ signal.

• In a studio, often used to add a sense of space or natural acoustics.

• Great if you have a good sounding room

Ambience

• Generally thought of as the character or quality of some environment.

• In audio, we specifically mean the acoustical (sonic) characteristics of a space, including everything from the size of the space to what type of sounds are a normal part of it.

• ie the Ambience of Vector Arena will be different to the ambience of a large cathedral.

2:1 Rule of Ambience

To capture an equal amount of room ambience, a cardioid microphone must be placed twice as far from a source as an omnidirectional pattern microphone.

3:1 Rule

When using two microphones to record a source, place the second mic three times the distance from the first mic that the first mic is from the source.

Proximity Effect• An increase in bass or low frequency response

when a sound source is close to a microphone.

• Vocalists tend to like proximity effect since it fattens up their voice. But a constantly varying bass boost can wreak havoc on carefully set levels.

• So don’t mic too close to the sound source.

Proximity Effect - Guitar

Leakage/Spill

• From other instruments

• From headphones

• Uniquely, sound can reconstruct itself after it bends around an object.

Huber, D.M. (2001). Modern Recording Techniques. 6th Ed. Focal Press. p40

Leakage/Spill

• Barriers can be used to help control reflection from the room, and bleed from other instruments.

• Impossible to remove sound of another instrument which bleeds onto a vocal track.

Reflections

• Hard shiny surfaces, walls, floors, windows, ceilings.

• Can all cause phase problems.

Standing Waves• Attenuation or cancellation of sound waves caused

by reflections from parallel surfaces.

• This is why most recording studios try to limit the amount of parallel reflective surfaces.

• Occur when half the wavelength of a sound is equal to one of the dimensions of the room. In such a case the reflected wave from the two surfaces involved is in phase with the incident wave and a pattern of sums and cancellations will occur.

Standing Wave

Rumble

• Low frequency sound caused by passing cars or air-conditioning etc.

Always remember the GOOD rule!

GOOD Musician +

GOOD instrument +

GOOD performance +

GOOD acoustics +

GOOD microphone +

GOOD placement =

GOOD SOUND!!

Acoustic Guitar• A balanced sound can be achieved by placing a

mic (or an X/Y stereo pair) slightly off-axis and below the sound hole at a distance of between 10 - 20cms.

• Two cardioid mic’s are placed with their grills as close to each other as possible without touching and facing at angles to each other between 90° and 135°.

• Mic’s to use? Condensers, because of their sensitive frequency tranduction.

Recording Acoustic Guitar

Acoustic Guitar cont.

• The sound hole serves as a bass port which resonates at lower frequencies.

• Miking too close to the front of this port will result in a boomy / bassy sound.

• You can use EQ to roll of 5-10dB at around 100Hz.

Voice• Usually use a large diaphragm condenser mic.

• Loud rock singers sometimes work best with dynamic mics.

• Mick Jagger and Phil Collins are reputed to prefer dynamic mics to get a more puncchy, mid sound. (Quote from Soundonsound. Microphone types & characteristics.)

Vocals - common considerations

• The voice is prone to excessive sibilance (s, sh, f) between 4 - 8 kHz.

• Plosives (bursts of air) can occur with p, b and k lyrics.

• Excessive bass boost due to proximity effect. The solution is to increase the distance from the mic or use a ‘wider’ polar pattern such as ‘omni’.

Voice• The human voice has a large dynamic range.

Good mic technique can help.

• Place the mic slightly above the mouth of the performer. This helps open the throat.

• If the headphone level is too high or too low it can be off-putting for the singer and can also create pitching problems.

• Having one headphone off can help.

Voice

• Some singers like a little reverb on their voice in their headphones.

• This can help with pitching and make them feel more comfortable with their performance.

Use your ears!!!

• Whatever miking position you use - small changes in position can make a huge difference to the sound.

• When miking - close your eyes and LISTEN to the sound you are getting.

• Use your ears to judge what sounds best.