There are MP3 pure test tones (from 10Hz to 300 Hz in 1 Hz increments) that can be downloaded from RealTraps website and which you can burn to make a test CD. The digital Ratshack meter is another essential tool with this approach. There is a plot that you can use too. As the 10 second pure tones maximize the room modal response, I suspect that it is best to eyeball the curve and concentrate on taming the broader "bumps" rather than trying to eliminate the inevitable sharp spikes/troughs that you get with a CD with single frequencies.
A PEQ, used sparingly, seems to be another essential tool in practice. (for example It may not be acceptable to install the significant amount of bass traps that might be needed to make an impact on a large room with significant modes below 60 HZ)
A PEQ, used sparingly, seems to be another essential tool in practice. (for example It may not be acceptable to install the significant amount of bass traps that might be needed to make an impact on a large room with significant modes below 60 HZ)