Was trying to measure a Paradigm Sub2 Frequency Response last night, and this same phenomena happened when trying to recalibrate the sound card.Toubleshooting
For some reason, sometimes when you run a sound card calibration, you'll get a really "noisy" result with lines all over the place like in the attached picture.
As far as I can tell, this is possibly the result of a few things:
1. Your cables are all twisted. Try untwisting them.
2. Your AC cable from your laptop is too close to your RCA cables.
3. Your Latency (see post 1) needs to be adjusted higher or lower (note, you have to exit REW to do this).
Sometimes this keeps on persisting, and you may need to reboot. I have no idea why this happens but playing around with the above seems to make it eventually go away.
Now, when actually running measurements, sometimes you'll hear this "noise/warbling" of the tone coming out of your subwoofer. Cancel the measurement, and check all of the above again. Usually it has something to do with the cables in my experience and fiddling with them tends to make the tone go away. Sometimes you just have to keep running measurements a few times and it just suddenly works.
I know, it sounds weird, but that has been my experience (I actually bought a new MobilePre thinking my last one was shot).
Other Items to Check
Download the most recent version of Java ....
Exited REW, increased the latency to 4096, went back in and all was good.
Seems to be the proper "fix" for whatever it is that is happening. At least in my case.