Wondering if anyone has encountered this before. With Bruceks help i have my tascam 144vcalibrated, and got through my first measurement. I was running my laptop on battery, and it finally croaked so I plugged it in. I immediately got a bad humm and slight crackle from my sub. any thoughts? Running on battery will be difficult as i have one of those big 17inch battery hogs. Any help would be much appreciated.