http://www.amazon.com/Polk-Audio-Monitor-10-Inch-Subwoofer/dp/accessories/B00030CHQ2

-These aren't refurbed, and come with free shipping as well.

Thanks. I ordered one

Another idea to be thrown out there at the same price... I bought one last week. Amazing (but somewhat bulky... barely fits under the cabinet)

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-635

The amazon link is $10 cheaper at $90. I'd just go with them.

Can someone point me in the right direction on how to wire these up to a pin?

Thanks!

^basically just some alligator clips, speaker wire, and a sacrificial RCA plug - clips onto original subs +/-, wire up RCA plug, insert into Left or Right input (or just use alligator clips, and connect the speaker wire to the left/right inputs)

A buddy of mine just typed this up to me in an email a couple weeks ago. I'm copying/pasting.

"Yeah the self powered sub is a piece of cake. Most ext self powered subs have 2 speaker lines in (positive/negative) so you run a pair of wires from the speaker in the cabinet and the big speaker in the backbox thru the back of the game and to the sub. The sub will then play the low/base sounds for the game that went to the cheap original game speakers. That is pretty much it. And if you don't want the sub on it or you want to sell the game, you simply unhook the wires from the speakers and you are done. The cabinet speaker is 1 channel and the 2 backbox speaker are actually 1 channel (2 speakers in parallel but from the same source). It is pretty easy and the game stays original using the self powered sub. And the fast that the sub is self powered, it doesn't require any extra juice from the game to work!"

I ordered a black one through Amazon. I guess we'll see how it goes.

Better to just clip the 2 terminals of the large cabinet speaker and connect those to the sub input. No need to touch the backbox speakers.

If you don't hook up both the large cab speaker, and the backbox speakers, I don't think you are going to get all the low end audio through the sub. There is audio that gets played in the backbox speakers that doesn't in the cab speaker.

Keep us posted I am pondering doing this as well but not sure how it will sound in the end. Please let us know what you think once your done.

Have you tried this yet Coaster? If so what do you think does it sound pretty good?

I will. I have it on good authority that it will kick ass. To each their own though, but I've spent $90 on dumber things

I was thinking of going to other direction and installed ear bud jacks in the cabinet. My boys had a bunch of kids over this weekend and when 7 pins are playing at the same time it gets pretty loud. I even have then turned pretty low but it just gets to where you cannot hear you own game.

I was thinking about trying to tap into the wiring and add a volume for each ear bud as well. Subs in each machine would be insane.

Anybody have pictures to share of what it looks like when hooked up properly?

Just tried wiring a powered sub that I had to TZ. Sounds nice!
However, probably wouldn't make an impact on most titles. Depends on the sound bites.