AVR Sub Pre-Amp out to Pro Amp Input help needed

[MY99 2.5GT]

I attempted to connect a Behringer EP4000 to my Yamaha RXV-663 AVR to drive a pair of 15" subwoofers (4ohms each). The AVR's subwoofer pre-out RCA's are rated at 1.0V/1.2k Ohms. If I'm reading correctly, the EP4000's input sensitivity is 1.23V (+4dBu). I purchased a Rolls MB15b to convert the unbalanced 1.0V AVR RCA signal to +10db XLR. With gain on the EP4000 turned all the way up, and line level gain on the Rolls turned all the way up, it could barely drive a single 15" subwoofer and introduced significant noise and interference.

I ended up returning the EP4000 and Rolls box after not being able to figure out what I was doing wrong . . .

Is there a pro amplifier you guys recommend to provide about 700rms x 2 @ 4ohms that would be compatible with my AVR's subwoofer RCA pre-out without additional noise/interference?

 

[WaynePflughaupt]

There’s no shortage of amps meeting your requirements from Carvin, Crown, QSC, Crest, Peavey, Behringer etc., just pick one.

That said, it’s likely that your receiver does put out enough voltage to drive the amp. The manufacturer’s ratings are often grossly off. I’ve seen models rated a 1 volt actually able to put out 4, for example.

But even at only 1 volt, that should have been enough to get that amp cranking to at least a respectable level. The fact that it wouldn’t even get off-idle with a huge signal boost tells me there was something wrong with it (Behringer does have a comparatively high failure rate).

Either that or your receiver just wasn’t putting out a signal, either do to an internal setting in the menu (e.g. subwoofer enabled or the sub gain trimmed all the way down), or it’s simply malfunctioning. Does it work with other more traditional self-powered HT subs?

Regards,
Wayne A. Pflughaupt

 

[MY99 2.5GT]

Thanks for the reply.
The subwoofer plays fine when hooked up to my BASH500 amp.
When connected to the Behringer EP4000 I had the sub woofer level cranked all the way up in the AVR settings.
Before adding the Rolls the signal was so weak that the amplifiers signal indicator lights wouldn't even register.
Right after testing I plugged my BASH500 back in and got normal output.

This is the second EP4000 I received with these issues. I processed a return for the first one two weeks earlier.
That is why I figured it was either something I was doing wrong or a technical incompatability between my AVR and the EP4000.

 

[WaynePflughaupt]

I’d recommend Carvin as a price-point option to the Behringer. Their power specs might not look as good as comparably priced Behringers, but Carvin rates their amps broadband RMS 20 Hz – 20 kHz.

Regards,
Wayne A. Pflughaupt