I've only had my EP4000 up and running for a few weeks now, so my experience with it is limited. I have input 1 of the amp connected directly to my Onkyo TX-NR809 with a single unbalanced RCA cable (with RCA to 1/4 adapter). So far, I've always had the clip limiter switches in the 'on' position. My questions go out to those more experienced with this amp... If I can make the red clip lights on the front of the amp come on, I'm assuming this means my receiver is pushing sufficient voltage from the sub output (and not the opposite)?
The amp is pushing dual 10" subwoofers in 1cuft sealed boxes which can easily handle 500 watts RMS each. The subs are dual 4 Ohm voice coils. I've run them with the amp in two different configurations. 8 Ohms stereo (voice coils of each sub run in series), and also at 16 Ohms bridged (voice coils of each sub connected in series and also the two subs connected together in series).
A couple observations...
Running in 8 Ohms stereo (amp in parallel mode), I'm able to get the clip lights lit up fairly easily during bass-heavy scenes in movies with the gain knobs at 26 (just past 12 O'clock). Running in 16 Ohms bridged (amp in stereo mode with channel 2 gain all the way down), I can get the clip lights to come on with channel 1 at 30 (3 O'clock position).
Although I seem to remember reading somewhere a long time ago that ideally only the voice coils (and not multiple subs) should be run in series (with it being fine to run multiple subs in parallel), the dual sub/amp combo sounds much better at 16 Ohm bridged than 8 Ohms stereo. In series, the two subs seem operate more in sync with each other than in stereo (although I suppose they may sound better simply because the amp might be putting out more power at 16 Ohms bridged than in 8 Ohms stereo).
Anyway, given the fact I can get the clip lights to come on (with the clip limiter switches on) in either mode, can I assume the following?...
a) the payoff (if any) of turning the clip limiter switches off might be outweighed by the increased risk of damaging the amp/subs?
b) my Onkyo receiver is a stud, and the signal it pushes is plenty hot to drive the EP4000?
Thanks to anyone who is willing to lend their wisdom/experience with this amp.