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:

Behringer MX 2642A

% THD
50 Hz .048
100 Hz .05
1000 Hz .05
10 kHz .058
15 kHz .064

IM distortion (60 & 7kHz) .06 %
noise* .0355 mv

Soundcraft F1-16

%THD
50 Hz .048
100 Hz .05
1000 Hz .052
10 kHz .06
15 kHz .068

IM .052 %
noise* .035 mv

Mackie 32-8

%THD
50 Hz .052
100 Hz .058
1000 Hz .05
10 kHz .064
15 kHz .072

IM .06 %
noise* .09 mv

no mixer: straight from sig gen to analyzer

%THD
50 Hz .046
100 Hz .048
1000 Hz .05
10 kHz .056
15 kHz .062

IM .052 %
noise* .014 mv

*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