The purpose of the subwoofer is to provide a lower frequency response/ bass that will go lower
than your regular speakers as well as augmenting them. The real cheap subs more than likely
are not going to provide any lower bass than your regular speakers. You pay more you get more.
Emotiva and other brands have lower priced subs that get good reviews. You might want to look
at what's available.

I'd sure like to have you listen to my 5.1 system that doesn't have a powered sub in it.;)

The power cord isn't a standard wall plug?

^^^ I'm guessing that one of the small gauge wires is called 'power' and it goes back to the amp...not a wall fixture.
The pic of the back of his sub shows only wires of the same size.

A powered subwoofer has an internal amplifier and is plugged into a wall receptacle. I think
some of the confusion on this thread is about that. A passive sub is like a regular speaker
that connects to the receiver. I believe Flattbutts sub is passive. The word powered has been
loosely used here and I don't think it applies to the Op's sub. The receiver is not providing power
to the sub it is sending a musical signal.

OK so to close this out...nothing worked. I tried everything suggested here and no joy. I'm ready to drop kick this thing into the pond.

Thanks all...I'm done.

^^^
subwoofer becomes subtweeter.:D

Most of us, including me, thought you were dealing with an amplified subwoofer...which plugs directly into the wall.

With yours...you may not find a way to hook it up....which is sad.
Some components are matched to their own..with no consideration to the owner for substitute.