Some months back I won an auction for a Behringer 802 on eBay, but the seller screwed up and sent me an Alesis MultiMix 8 USB instead. Without going into the details, I got to keep the Alesis, even though it’s considerably more expensive than the Behringer. It didn’t take me long to figure out that since the MultiMix has a USB output, it has the capability of being a “one package” option for REW, compared to the 802, which must be used with a separate USB sound card.
Problem is, I’m having trouble generating a viable soundcard calibration file with this thing (this is only the second time I've calibrated a soundcard, the first being the Soundblaster I've been using). Separate measuring attempts using different combinations of Input and Output Device options (i.e., "Default Device," "USB Audio") have resulted in graphs like these:
Changing various OS options offered for the Alesis has made no difference. As best as I can tell, the problem is that the Alesis doesn’t provide the option of letting REW control the input level:
When I instead attempt to use the Alesis’ various trim and gain controls to adjust the level during the calibration routine, nothing happens at first, and then suddenly the signal goes from nothing to clipping, both with the REW input meter and the Alesis’s output meter. At that point the level is very “touchy” and difficult to adjust. When I am able to stabilize the signal level and run the soundcard calibration routine...
...I get graphs like the ones posted above.
If I disconnect the Alesis from the computer, its own meter level remains stable, which tells me the meter is not showing a signal originating from REW. It appears that the Alesis is having an internal feedback problem.
It’s looking like my only option for getting a calibration file will be to feed the MultiMix analog inputs and outputs though my Soundblaster soundcard. Any thoughts?