Tim Perry wrote:

i decided to run some measurements on the Behringer mixer i just got then
compare it to some other mixers. here's what i got:


snip near identical figures

*methodology:
noise measurements made referenced to -40 dB input and 0 dB output with sig
gen muted and one ch open all others down.
all other measurement made with 150 ohm source at -40 dB into mic input.
mixer output set to 0 dB into active balanced (transformerless) meter. tone
controls all at neutral.
in "straight through" measurements the sig gen output was increased by 20
dB.

conclusion: i was rather surprised at how well the 2642 tested relative to
the other units.
the online spec sheet claims a THD of .007% @ +4 dB
i wonder if its an actual measurement or is derived in some fashion.
my equipment seems to be functioning within its specified tolerances.
http://www.pi-usa.com/ag51/ag51g.htm#SPECIFICATIONS

Your measurement gear is rubbish.

With residual figures like that - you'll never be able to measure anything
meaningful. You're simply measuring the test equipment.

Audio Precision kit for example, typically measures 0.0007% THD ( 7 parts per
million ) that's -104dB SINAD if you prefer a dB version, with output looped
back to input ( certainly at 1 kHz ).


Graham