tonyptony;230390 Wrote: > I agree that's a head scratcher. If Hugh is right that means your > measured curve should look quite a bit different.
Hang on - both Inguz's test and my own observations make sense. DRC applies mic calibration to the filter, not the TestConvolution which means that all those frequency responses are without mic calibration and *are* comparable. This has been tying my mind in knots, but let me try to explain further. When DRC calculates a filter it uses the raw impulse response, which in my case has a big low freq drop off due to the mic sensitivity there. Without mic calibration DRC would produce a filter with large low freq gain in order to try to make the response flat. But it uses the mic calibration data so that the filter actually just tweaks the low freqs as requied. When that filter is then applied to real (flat-ish) music, the result is flatter (tweaked) music. Now when the same filter is applied to our measured impulse response (with the low freq drop off due to the mic), it produces a similarly shaped (though tweaked) output. The problem with Inguz's test is that he was using an already flatish freq/impulse response, but then applying a filter adjusted for a 'bad' mic. That would be equivalent to me using a perfectly flat mic, and an extreme/incorrect mic calibration file. In other words a filter created for a particular mic expects to see an impulse response created by that mic when calculating the TestConvolution. So in summary, what we see in REW, whether measured with ot without EQ, or TestConvolution is the frequency response before any mic calibration, and all are equally comparable. Perhaps someone can explain better.... -- mortod ------------------------------------------------------------------------ mortod's Profile: http://forums.slimdevices.com/member.php?userid=4651 View this thread: http://forums.slimdevices.com/showthread.php?t=35615 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
