Best Discs for SPL Measurement?

[Active Speaker]

Some people say use Avia, some Video Essentials, some the Hsu test disc, some the Stereophile disc; what are the best discs to measure SPL across the entire audio frequency? Are there any others that are useful besides these four?

[Retread]

Originally posted by Active Speaker
Some people say use Avia, some Video Essentials, some the Hsu test disc, some the Stereophile disc; what are the best discs to measure SPL across the entire audio frequency? Are there any others that are useful besides these four?

Best? Probably a subjective, arguable topic.

The Hsu disk is very good, and it's free. I've used the warble bands a lot, and it works well with a Radio Shack SPL meter.

I have the new "Digital Video Essentials" DVD and am just learning how to use it. Something of a pain to navigate to what you want.

My current favorite is TrueRTA, which is a program that runs on a computer. It has sinewave, white noise, and pink noise generators, as well as both oscilloscope and spectrum display modes. It also has a chirp that sweeps the entire spectrum at fixed frequency. The first step is a self-calibration mode that produces a file of compensations for internal imperfections in the computer sound system. The second step is to create a file listing frequencies and adjustments for the microphone being used. Once those steps are done, what you see is what exists at the location of the microphone. One chirp and the complete spectrum for that microphone location is available to save to memory. There's a mode whereby one can chirp one location, save, chirp another location, sum to the first, chirp another location, etc., so that an overall spectrum in the room can be developed.

[Rob Babcock]

The Rives Audio test CD is great- it has a series of sweeps and tones that are calibrated to the deviations from flat inherent in the Rat Shack analog SPL meter. This is great; you no longer have to add or subtract from a table to figure out what you're measuring.