- Thread Starter
- #21
Not exactly.
1) REW sends sweep to BlackHole output ch. 1
2) Reaper acquires BlackHole input ch. 1 (looped back from REW)
3) Reaper is configured to reroute audio to BlackHole output ch. 2
4) REW acquires BlackHole input ch. 2 (looped back from Reaper)
There is no overlap if that is your doubt.
It is only in this precise configuration that the signal degrades.
If I play the REW's sweep with another app, like Apple Music or Audacity or any other player, and use the double loopback config as said before, everything works normally: THD+N below -140dbfs.
It's pretty weird and I think it depends on how REW handles drivers or how Core Audio works.
But that's not the only anomaly with REW: I have noticed that in direct loopback measurements via Blackhole (ch1 out to ch1 in), if I start signal generation first compared to the acquisition of RTA, it is not possible to use a rectangular window, there is a lot of noisefloor fluctuation. As if there was a clock problem. But if I do the opposite, first I start RTA and then the generator, all perfect.
I suspect that the problem with the measurement via sweep is correlated and depends on the opening of the devices.
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