I am unsure of how your amp would respond since tying the backend of two channels together could cause them to develop some sort of feedback loop. I am curious regarding the need to feed those speakers more power than you are getting bi-amped. From what specs I could see they are 90 db efficient and should have plenty of power as is. If you feed those woofers too much power they could extend beyond design. Since Energy makes their own drivers you should contact them for specifics. I would steer away from anything that could damage the amps or the speakers, especially if it already sounds really, really good.