Help with 5.1 subwoofer connection

by Anonymous

I was wondering if someone can help please, i have brought a surround sound system SPEAKERS AND SUB ONLY,and am now trying to find a second hand amp to run them,the only trouble is,the sub is the same as the speakers {ie has two wire to run it}and not the normal rca type connection...

Every time i find an amp with 6 or 7 speaker inputs (ie red and black) when i look closer, EVERY SINGLE ONE the sub input seems to be the rca type. I must of looked at over 100 different systems now on ebay and i find it hard to believe that none can run my sub.

What do i need to look for??

Hope this makes sense
many thanks in advance for any help

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Hi Anonymous

My guess would be that you have bought a speaker system with a non-powered/passive subwoofer. This type of sub would usually have standard speaker connections rather than a single RCA.

Most AV receivers you will find are designed to be used with an active subwoofer (which has it's own amp inside the unit) - hence the single RCA. This connection sends a line level signal which then needs to be amplified - and this amplification is done by the active sub.

Assuming I am right and it is a passive sub, then I see a couple of options.

1. Buy an active sub. You can still use the other speakers, but with an an active sub you will be able to directly connect to any AV receiver.

2. Use an old amplifier to power the sub. If you have an old amplifier lying around, send the RCA from the AV receiver into this, and then connect the speaker outputs to the sub. This may work ok.

3. Buy a dedicated sub amplifier. Something like the Dayton SA70 70W Subwoofer Amplifier here at Amazon may do the job. This takes the RCA output from the receiver, amplifies it and outputs it via speaker connections.

Anyway, that's my take on your issue. Maybe somebody else has something to suggest?

Hope that helps.

Paul (Site Editor

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