Test CD

[u235]

I just met a guy whose thing is acoustic engineering. Builds speakers, amps, etc, consults on room layouts, and a bunch of stuff, based in Pretoria. I got a test CD from him that has a wide range of individual frequencies, white brown and pink noise, etc. I recall someone was looking for a test CD a while back. If anyone is interested, his name is Eben, number 0823265044.

(It was fascinating moving around my room, changing speaker toe and separation, and finding loud spots/dead spots/bad image spots!)

Also interesting to hear 40Hz as sound, but 31.5Hz just as the driver thudding. For the record, I can't pick up the 16KHz signal with both ears, and even the 12.5KHz sounds extremely high-pitched, far higher than the base frequency of any instrument except maybe King Crimson in a weird moment.

[chris]

Did you wear a diaper for the brown noise.

[Viagara]

Did you wear a diaper for the brown noise.

ROTFLMAO! 

[u235]

Ah yes, children. The education never stops. Alimentary, my dear Watson.

"Some people use the term brown noise as a synonym for brown note, a controversial and unproven sound which causes the listener to lose control of their bowels.

In science, Brownian noise ( Sample (help·info)), also known as Brown noise or red noise, is the kind of signal noise produced by Brownian motion, hence its alternative name of random walk noise. The term "Brown noise" comes not from the color, but after Robert Brown, the discoverer of Brownian motion.

The graphic representation of the sound signal mimics a Brownian pattern. Its spectral density is inversely proportional to f², meaning it has more energy at lower frequencies, even more so than pink noise. It decreases in power by 6 dB per octave and, when heard, has a "damped" or "soft" quality compared to white and pink noise. The sound is a low roar resembling a waterfall or heavy rainfall. See also purple noise, which is a 6 dB increase per octave."