One of my R80's hits its thermal cutoff very quickly. My other r80 which is receiving virtually the same signal (obviously some difference because of stereo sources but negligible) does not overheat at all, (they both feel the same on the back though, pretty warm) They are both in the same room, same ambient temperature, nothing in line with them (hardware eq, xover, dsp etc) Both have the 80hz filter engaged. I'm starting to think it might be defective. It only takes about 20 minutes from initial cold start, at very modest volume. HELP!