Hi, I have AVR250 connected to KEF XQ5 (2 front speakers) and a Sub. Once I bi-amped the front speakers, I could not longer get any signal to the subwofer in Direct Stereo mode. The sub will play only if I trun off 'direct stereo' . - Is that they it works or did I missed something in the setup? I have the speakers setup as Large+Sub. Thanks.