I had an install already with a ma amp and hifonics amp and everything was fine. I swapped out those two amps for a jl 300/4 and the mmats amp and added the btl. A good test might be to run a different speaker at 1 ohm and see if there is a problem or run the btl on someone else s amp to see if that's the problem. What do you think? Yeah that would be a good test. Just make sure the new sub can handle the full output of the amp, or at least most of it, so that you can run it decently hard to see if it will cut out. But you don't want to blow the test speaker, obviously. That would suck. When you tested the sub's voice coils, did you test each coil by itself or did you already have them wired together then tested the speaker wire from both? You might try testing each coil by itself. You may have one bad coil and one good coil, and the DMM would only pick up the good coil. You say you had it wired to 2 ohms on another speaker and it was no problem. That kinda leads me to think there may be something wrong with the amp running at 1 ohm. Maybe it's finicky. But yeah, also try out your wild beast subs on there at 1 ohm.
