Most room environments are not designed with the acoustical properties in mind, but rather other aesthetic or practical objectives are of primary importance - until it becomes necessary to either work with sound or enjoy the listening experience without the room's signature detracting from the ability to distinguish detail, proper spectral balance or spatial cues. The answer is to either design the room from the beginning taking into consideration the acoustical properties, or to correct the problems later using any of several techniques.
RR Audio provides acoustical analysis and design services for
If you are planning a new room design or want to correct the one you have, give us a call.
Acoustical problems in critical listening environments can be a real nightmare. In the case of a project studio in the home, what normally would make for a comfortable den or bedroom can be a disaster when you are trying to evaluate
your latest recording. In the case of a working recording studio, anomalies in the room acoustics can be inadvertently compensated for when mixing the recording, causing the mix to be incorrectly balanced when taken out of the original environment. In the home listening environment, although acoustical problems are not threatening your livelihood, they can be extremely annoying in that they interfere with the ability to "get inside of the music", creating the illusion that
you are "there".
Acoustical analysis is accomplished by generating a series of impulses (similar to handclaps) which contain all frequencies up to ½ the sampling rate used and feeding the signal into the room via the playback system. Several different signals with different sampling rates are used to allow for the maximum detail in the data to be acquired (tests
are done with data to 23kHz, then another test is done with data to 4kHz, then again with data to 500Hz). The reason for this is it allows for more data points to be available at the lower frequencies, so that when zooming in on the lower frequencies there is enough data (without large gaps between data points) to evaluate the problems without having to interpolate data. Microphone placement in the listening position is tested first, then additional tests are done with the
microphone in specific problem areas to confirm that the problem data is correct.
Once the data has been acquired and transformed into the various plot types, the information is evaluated and design work is begun to correct the problems. Many different solutions are available to correct the various kinds of problems which may exist — some methods being more costly than others. After determining which are the primary causes of the problems, several methods of correction are outlined and the required materials and devices for correcting the problems are listed in ways which allow choice as to method vs. budget. The client is then consulted as to which method is preferable, at which point design of the final system is begun.
Computer-aided design of devices, layout of the room, and plans for building the various devices are completed and final approval is gained from the client before construction is begun. Some of the devices used in the correction of
typical acoustical problems include:
Parabolic Reflectors — these are curved devices which are generally placed on walls (a different type is used on ceilings) to spray the soundwave on paths which tend to break up standing wave modes. When used on ceilings (generally over a larger area than the wall-types) these devices not only break up the standing wave between parallel ceiling and floor, but reflect the soundwave towards the walls, where absorption by the wall treatment and any acoustical panels can occur.