Onkyo TX-NR1007 AVR vs. Crown XLS-202 vs. Behringer INuke DSP 3000 in room Omnimic frequency...

I've got two amps handy and my Onkyo TX NR1007 - let's compare the FR on these three and see how much variance there is in audible frequency between these audio power sources. Anyone care to hazard a guess on the result?

I'll be measuring the FR response of a pair of eD Cinema 12s. For the comparison I'll turn off the subs. Set the Onkyo AVR to Pure Audio mode - NO EQ will be applied in PURE Audio Mode. The speakers will be set to large full range - SPL levels will be matched for each capture. The frequency responses will be captured by averaging 25 captures. My room and mic setup will be identical for each capture. 1/12 smoothing will be used.

This is an exercise in curiosity. I'm purchasing some new speakers soon and may choose to power them with an external amp. I'd like to know the differences or possibly lack there of.


EDIT - photobucket link to the FR album from this testing.
http://s1191.photobucket.com/albums/z472/jvonengeln/Amplifier%20Comparison/
Edited by Archaea - 2/9/13 at 4:04pm

I finished the first round of testing. I measured each amp in stereo on Pure Audio mode on the Onkyo - no EQ. The FR graphs were pretty close. The Behringer seems to have a bit more treble at the upper end of the audible spectrum. I'll probably repeat the tests to confirm -- perhaps with just a single channel/speaker to eliminate the possibility of a speaker bias to left or right of the room affecting the FR.

The noise floor in my room was about 60dB, so I cranked the omnimic sine sweep test tone well above the noise floor.

I just did a second round of testing with only the left channel playing instead of the previous stereo testing. The test results are very similar to my first test. It does seem the Behringer INuke DSP 3000 adds a bit more treble at the top of the audible frequency response graph.

For the second test, new averages were captured only from the left most speaker. SPL's were level matched between the three amp sources. The Mic position was standardized from a left chair listening position (different mic location from the first tests, but identical and unmoved for all three tests). Respectively nothing changed in the graphs related to frequency response bias from the first test. It does seem the INuke has a bit more treble at the top end of the audible spectrum (2-3dB more), followed by the Onkyo and in both tests the Crown has a just about a dB less than the Onkyo at the 20khz/ top end of the audible spectrum.

hey ecrabb!

I hope all is well.

Yeah - both Crown and Inuke were powered off the same stereo L and R rca preout on the Onkyo receiver. I'm not sure what to make of it, but I think it is slightly audible, as well as visible on graphs, that there is a slight bit more treble on the Inuke when playing mains with my Onkyo TX-NR1007 as the source.