Yep, the l-pad would be a pair of resistors, if I ended up doing it. So far in testing, the noise hasn't bothered me. The problem with the FIR filters is the only device that can do it is the pwr-ice 250 (and I guess my pc if I switched over to pc based filters). If I could change the subwoofer crossover to FIR that would solve it, but the minidsp 10x10 won't do FIR. Rephase is the tool I was using. It's connected right now with a chromecast that drives the 10x10 through toslink, and then the aes/ebu output goes to the plate amps..the 10x10 is essentially my pre-amp, so I would have to add the same amount of delay to the subwoofers that the pwr-ice plate amp dsp introduces in the next step running FIR, and then any additional delay any of the subs might need to time align otherwise, so the problem is running a subwoofer crossover IIR with FIR up top. I could always introduce an FIR step between the chromecast and the 10x10 using one of their...I dunno, like a nanodigi or one of those. For now I think I'll just keep it IIR, and if I really get the itch to try FIR, I'll switch to a PC based system with a Motu 16 or something and run BruteFIR, and re-wire the plate amps to bypass the dsp module, but that's a wayyy maybe down the road thing.