Maximising the acoustics of your meeting room

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Maximising the acoustics of your meeting room

• Glyn Chapman
• Acoustic Arrangements

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Room Acoustics

• Reverberation
• Intelligibility
• Feedback
• Sound System Equalisation

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Reflections
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Shapes of room

• Worst possible room shape is a cube.
• The next worst is a room where all dimensions are
  multiples of the height. A pretty horrible
  example is a room 6m high, 12m wide, and 18m
  long.
• A good shape would be, say,
• 6m high, 10m wide and 14m long

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Building Construction

• Sound Absorption Coefficient
• Example
• Painted Brick 0.02 _at_ 1khz
• Drape (18oz) 0.48 _at_ 1khz
• Pleated Drape 0.75 _at_ 1khz
• Full absorption 1.0 Full reflection 0.0

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Acoustic Treatments

• If it soaks up water, it soaks up sound!
• Carpets, Drapes, Soft Furnishings
• Acoustic Panels
• You cant fix it in the mix!

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Graphic Equalizers

• Removes rooms resonant frequencies
• Increases headroom
• Improves tonality
• Increases intelligibility

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How to set your graphic eq

• Pink Noise and RTA
• Auto EQ products dbx Driverack
• Ringing Out
• Sensitive flat response microphone.
• Flat EQ on mic channel and graphic.
• Set gain level just below feedback.
• Increase each band until feedback and reduce
  by inverse amount.
• or
• Increase gain until feedback and reduce
  offending frequency.

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Mid Sweep EQ
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Loudspeakers

• Placement
• Dispersion
• Point Source v Distributed

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Other Tools

• Notch Filters
• Feedback Suppressors

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