Onkyo M-504 + Subwoofer

[manilaice]

Hello, My Amp does not have a sub-out. How can I hook one up? Advice and Alternatives are welcome. Thanks, MIce

 

[Alex at SVS]

The M504 being just an amp, it isn't supposed to do signal processing such as handling the crossover to the sub. If you have a pre/pro, then there should be a sub out from that. If not though, then likely your sub has either high level or low level inputs and outputs (many subs have both) so you can run your wires directly to the sub and the sub's internal crossover can handle the transition between the sub and your main speakers.

 

[manilaice]

I have an Onkyo P-304 Preamp hooked with it. no sub-out. Do i need a passive or powered sub woofer? So, i would connect the l/r speaker wire to sub-woofer in then out to speakers? I was wondering also if i could connect the sub from the tape rec out to subwoofer line-in connectors? Thanks again.

 

[Alex at SVS]

I have an Onkyo P-304 Preamp hooked with it. no sub-out. Do i need a passive or powered sub woofer?

Passive or powered doesn't matter for setting up the cross-over, that's only whether or not you need an external amp for the sub.

So, i would connect the l/r speaker wire to sub-woofer in then out to speakers?

Yes, that would be perfect.

I was wondering also if i could connect the sub from the tape rec out to subwoofer line-in connectors? Thanks again.

You could, and the sub would play the bass, but there'd be problems. The cross-over frequency is selected at the point where your mains stop playing the bass and the sub begins to (usually around 80Hz). The signals going to each the main speakers and the sub are each filtered by the crossover so that they only play what they're supposed, and trying to have that transition between main speaker and sub be seamless is the goal so you don't even notice the sub. To manage this, crossover rolls-off the signal starting at the specific frequency and bring it down at a specific rate so the sound level stays consistent going across the transition.

A test for this is on THX DVDs (the last test that starts at 200Hz and sweeps down to 20Hz) which you can run to hear this yourself very clearly.