The design specification for the control room was set to achieve a highly accurate monitoring environment.  The requirements for this were:

1. Low Frequency control.  Frequencies with wavelengths approaching the size of the room require special treatment.
2. Short, diffuse sound field.
3. No early lateral reflections within 20ms with a level greater than -10dB (ref signal)

The low frequency control is contained in the room dimension proportions so that the modal distribution of the low frequency support is well balanced.

The short diffuse sound field is obtained by incorporating a highly absorbent front end with a highly diffuse live end.

Designing the monitoring into the front end of the control room ensures that the sound sources are positioned so that they do not product early lateral reflections which smear the sonic image. | top |

RECORDING ROOM

The design specification for the recording room included:

1. High sound isolation
2. Multiple isolated recording booths
3. Variable reverberation time
4. Essentially diffuse sound field except for specific sounds

Sound isolation was obtained through dual shell design, rubber isolation of sub-structure, door seals, lead lining critical sound paths, double glazed windows and air lock doors.  | top |

Isolation booths were constructed with angled walls to obtain non-symmetrical pressure waves.  Variable reverberation time was obtained by constructing hinged panels that were highly reflective on one side and highly absorbent on the other side.  Sound field diffusion was obtained by the use of poly-cylindrical diffusers, angled isolation booth walls, ceiling angles and multi-radius array ceiling diffusers. 

The ceiling design is a multi-radius diffuser array.  This system was developed specifically for this room when simulations showed that there would be a notable late reflection wave series caused from mirrored parallel surfaces.  IE, the sound wave would reflect off one ceiling panel, then the floor and then the other angled ceiling panel and repeat this process producing what is commonly called “flutter echo.”  The radii and lengths of the array were designed to affect a frequencies above room mode resonance so that it would not degrade the low frequency response if the room.

The side wall convex baffles are called a poly-cylindrical diffusers.  These baffles are broadband frequency devices.  Their main benefits are low frequency sympathetic resonation and mid/high frequency diffusion.  These devices were chosen for their ability to smooth out the low/mid frequency response of the room as well as providing extra diffusion. 

Diffusion is possibly the most important aspect of recording room design.  It is the factor that gives a room ‘space’ and makes you feel relaxed.  If a room has constant repeated wave reflections it will sound cluttered and cramped.  When recording, is it most common to need an open type of sound, and in reality, this is the hardest to get.  The main recording area was designed exclusively to attain this goal.  | top |

The isolation booths were designed to produce sounds that could be tailored anywhere from intense to dry to intimate.  This gives recording engineers all the tools they need to cut any sound they may require. 

Source: Ben Hall (BMus (Music Technology), AMusA), Matrix Audio