Help Installing Sub + Bookshelf Speakers

[Clizzark]

I am currently running a Pyle PCA1 Amp connected to two SB3000 bookshelf speakers. The Pyle goes to my sound card... everything is working great.
I want to add this subwoofer:
Pioneer SW-8 100W Powered Subwoofer
http://www.newegg.com/Product/Product.aspx?Item=N82E16882117402
(Not for that price )

Here is the amp: http://www.amazon.com/Pyle-PCA1-30-...1?s=electronics&ie=UTF8&qid=1338688410&sr=1-1
Here are the speakers: http://www.amazon.com/Sony-SS-B3000...3?s=electronics&ie=UTF8&qid=1338688459&sr=1-3
Here is my sound card: http://www.amazon.com/Diamond-Xtrem...1?s=electronics&ie=UTF8&qid=1338688483&sr=1-1

I realize that I can hook up the speakers to the back of the sub and run them... but how do I get all back to my computer?
Do I need another amp?

Thanks guys!

 

[JLuchinski]

That's strange, it only has the high level in for speakers on the back, usually there is an out as well to go to your speakers. I think that was meant for if you had an amp with a and b speaker outputs, where you would just run the speakers from b to the sub. There is a line level in, but it doesn't look like you have any dedicated sub line outs. I would look for a sub that has hi level line in and out, where you take the speaker wires and where you would normally hook up your speakers you take it the high level in on the back of the sub and hook up your speakers to the high level out on the back of the sub and the sub will only put out bass, not treble. I hope that helped and wasn't to confusing.

 

[Clizzark]

Since my soundcard is for surround sound, it has ports for front, rear, side, and SUB. Can I run an RCA to 3.5mm cable from the LINE IN port on the sub to the sub port on the soundcard?