Recent content by twelti76

Also, I listened to the current one and it is fairly loud, almost distorting. A 20 dB louder stimulus would grossly distort and blow my ears out.

Makes sense. I guess I have to figure out how that could have happened! The current (today) measurement is the 20 dB lower one. I can confirm that the output gain on the mixer is at 0 dB now, which it should have been for the previous older measurement. Thing is, the RME output max is +6 dB...

I have been having some difficulties getting consistent calibrated measurements. For example I have a set of two different measurements done on two different days that look exactly the same as far as cal settings, but show up around 20 dB different. Same "dBFS @ 94 dB SPL" setting, same mixer...

OK, so now most of that delay is gone but still a couple of samples acausal (?). The delay is small, at around 10uS, possibly 2 samples at 192, if we assume that 0 time should be just before the start of the IR.

OK, I did use that at some point a couple of days ago, so maybe it got set then. But for a normal loopback measurement, I just set it to looback mode, set the correct loopback channel and measure, with the "timing offset" set to 0 then? Seems like there would be some similarities between...

Hmmm, I don't remember having ever changed it in the first place. I was playing around with some of the options to set or reset the 0 time reference. Maybe it happened then?

I saw that, but not sure where it came from. I simply turned on the loopback, set the correct channels to make a loopback measurement of a loopback and measured. I assume the timing offset was whatever it came up with for the "loopback", and was trying to correct for. Was it possibly...

Interesting: I tried doing a loopback measurement of a loopback. I used ch 5 for loopback and 6 for measurement. Seems maybe redundant but I actually got an acausal IR:

OK, thanks

I guess I'm wondering if it is possible to measure the loopthrough later and apply the measured delay to correct a previously made measurement, made without loopthrough? Same soundcard, same sample rate, same buffer size (maybe).

So, if I make a measurement using ASIO driver, the default is that REW puts t=0 at IR peak, but if I undo that, do I get the true delay of the system under test? OR, if I set t=0 in IR Windows and export, I also get true correct system under test delays?

Also, can to explain what "Undo t=0" does?

Wondering if REW would get correct phase values (latency) if not using loopthrough, but using ASIO drivers? I did some playing around and noticed for example that the delay to IR peak did not chenge in a loopthrough measurement when I changed the soundcard (RME) buffer size. So it seems that...

UPDATE: after careful review, it does look like the correct delay is there in Matlab. I did not know, or had forgotten about the import setting in "Analysis" section, so thanks!

OK, I'm trying to put this all in order in my head. One thing, is there a way to get the sample number at the reference time? If I could get that, I could export using it and import using it? Second, if I just export, after setting reference time to 0 in all measurements like I already did...