[Ryan Brown]

I have two bookshelf speakers powered by a home receiver. I also have a car amplifier powered by a computer PSU (350W). Then I have my two 12" subwoofers. There is a positive and negative speaker wire coming from the subwoofers that can/needs to be hooked up to something. There is a Left and Right speaker wire coming from the car amplifier that can be hooked up to something. There is a subwoofer output plug on the home receiver. I have heard that this plug will not actually power my subwoofers. Assuming this is true, should I use my home receiver to power my car amplifier to power my subwoofers? What would be the best way to power them? Do I need to power them in series to create an 8 ohm load instead of the 4 ohm load each subwoofer would send by default? Thank you very very much for any advice you provide.

 

[BassThatHz]

If you do parallel it would be 2-ohm, so I would think series (8-ohm) would be the safer wiring option.

Yes you can connect the LFE out RCA to the car sub amp's RCA inputs.
(The LFE-out won't power a subwoofer itself, it needs to be connected to an external amp)

If the PSU can't handle the juice, then you should just get one of these (which are made for 120volt AC wall sockets): http://www.parts-express.com/behringer-nu3000dsp-inuke-3000-watt-power-amplifier-with-dsp--248-6706
You need these to make the nu3000DSP work:
http://www.monoprice.com/Product?c_id=115&cp_id=11509&cs_id=1150902&p_id=4777&seq=1&format=2
http://www.parts-express.com/neutrik-nl4fc-speakon-connector-4-pole-cable-mount--092-050

 

[fbov]

I think the answer depends on the exact configuration of the car amp and subwoofer.

Assuming a 2-channel amp (There is a Left and Right speaker wire coming from the car amplifier) and a pair of single-driver subs (There is a positive and negative speaker wire coming from the subwoofers), I would think he'd want to use a Y-adapter to feed the LFE-out signal to each channel on the car amp, and connect each sub to its own amplifier channel.

In addition, be sure to wire the subwoofers in-phase (positive-to-positive) with each other and the bookshelf speakers, and adjust any filters on the car amp to maximum bandpass, as the AVR's LFE function is handling the crossover from sub to speaker.

Have fun,
Frank