I recently purchased 2 Behringer 315D speakers for my mobile DJ business. The setup I was running previously was as follows: Behringer Xenyx 1024 USB mixer, one American Audio PXW18P sub and 2 American Audio XSP-10A PAs. When I attempted to substitute the Behringers in place of the American Audios I got sound to the Behringers but the sub would run at a very, very low level. The signal light on the back of the sub would not light up and the signal light on the front of the sub would flicker just a little bit, if at all. It seems like the sub is not getting a full signal. After checking all connections, I then replaced the Behringers with the American Audios and the sub worked perfectly as it did before. I'm wondering if anybody has ran into this problem before and if so what can I do to resolve the situation. Thanks!