SynAudCon IR Exchange

By Pat Brown

The SynAudCon IR Exchange was formed to provide a simple, efficient means of allowing audio people to share their impulse response data.

SynAudCon is pleased to announce a new resource for our members – The SynAudCon IR Exchange.

We have written much in the past about the collection and use of impulse response measurements in testing rooms and sound systems. The IR is the “signature” that the sound system and room place on sounds that pass through them. It makes perfect sense, then, for the IR to be used as a “language” to describe what the listener is hearing at a position in a room.

The SynAudCon IR Exchange was formed to provide a simple, efficient means of allowing audio people to share their impulse response data. SynAudCon is dedicated to promoting the use of IR data as a means of collaboration between audio colleagues and advancement of the trade in general. This library of responses can serve many purposes:

  • 1. Acoustical problems can be effectively demonstrated. For instance, the IR for a room without acoustical treatment can be used to demonstrate to a client what can happen if they cut the budget for acoustical panels.
  • 2. Sound system responses, either good or bad, can be shared to allow further discussion on the SynAudCon Listserv.
  • 3. Microphone techniques can be effectively demonstrated. A recent addition includes the IR for a listener seat measured with 5 different types of stereo microphones.
  • 4. Loudspeakers can be compared. One project on the Exchange compares loudspeakers of differing directivities in a semi-reverberant space.

IRs on the Exchange can be opened in any of the mainstream measurement programs, or even with a simple wave editor. The most potential lies in convolving the IR with dry program material. This allows anechoic program material to be “listened to” as though it were recorded under the same conditions used to gather the IR. The powerful (and free) GratisVolver application allows a fast and easy way to perform convolutions (www.catt.se – see article, this issue).

Those who wish to provide IR data for the Exchange should simply email it to pbrown@synaudcon.com, along with some information about the room and how the IR was gathered. This will help users to understand what they are listening to. Figure 1 provides an example of an entry in the Exchange, and serves as a suggestion for what information should be included.

SynAudCon IR Exchange - Each entry includes some background information.

The IR Exchange will eventually include both predicted and measured IRs.. When possible, we will include a room model or DXF so that the user can experiment with prediction software.

As the contributions to the Exchange accumulate, we will have a very nice library of acoustical information that can be used by audio professionals worldwide to advance our craft. The SAC IR Exchange can be accessed at www.synaudcon.com. pb