Good low price sub, 10-12" or more?

The small size of your room means you really need a basic sealed sub, the problem is all that is available in this price range are poorly done ported subs. Your room is going to provide a lift to the low end response, you can actually get response to 20hz in a room that small with a basic sealed sub. While a ported sub will be extremely boomy sounding. This might seem a little crazy to you, but I recommend taking a basic DIY approach in order to get this type of sub. Take these components

http://www.amazon.com/Infinity-Reference-1260w-1200-watt-High-Performance/dp/B0028AVGEO/ref=sr_1_1?s=electronics&ie=UTF8&qid=1341778922&sr=1-1&keywords=1260w

http://www.amazon.com/Scosche-SE12CC-12-Inch-Subwoofer-Enclosure/dp/B003E476B0/ref=pd_cp_e_0

http://www.amazon.com/AudioSource-AMP-100-Stereo-Power-Amplifier/dp/B00026BQJ6/ref=sr_1_2?s=aht&ie=UTF8&qid=1341779147&sr=1-2&keywords=amplifiers+for+home

You simply attach wires from the sub to the enclosures terminal cup, place weather strip foam around the driver, drop it in the hole and install screws. Connect the LFE from to one amp channel, and connect that channel to the sub. This will also allow you to add a second sub for another $100 in the future. Other then the poor appearance of the sub box, this will give you a very high quality sounding sub, with amazingly deep response due to your tiny room.

Because of your price limitation, you could consider the Parts Express 12" which is ~$135 with shipping.
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-629

Individuals in this forum like the BIC F12 at around $200 and when on sale (also at $200) the Energy 10.3.

I think stomping your foot on the ground would produce more bass then that Aiwa could.

well you are in for a pleasant surprise with most anything you purchase then...

I would however clearly steer you beyond your stated budget to at least a BIC F12 type sub. It is about $190 on amazon and will be infinitely better than the AIWA sub. I owned one of those AIWA pieces of ......

junk.

It was my second home subwoofer. My first piece of junk sub I bought in a pawn shop. It was a passive 6" subwoofer. So the AIWA eight or ten I had was pretty cool to me --- at the time.

In the world of ID or commercial subwoofers you have to spend about $200 minimum to get anything worthwhile. Anything you buy below that price point just is just made with too cheap of components/amps to be worth even purchasing for all but the absolute lowest of expectations or needs.

Since you are happy with the AIWA if you bought something like this you'd probably initially think you'd died and gone to heaven

http://www.amazon.com/BIC-America-F12-475-Watt-Subwoofer/dp/B0015A8Y5M

^

---

that is until you heard a deeper frequency producing, more expensive subwoofer offering.

meaning it was not a actively powered sub, in this case I hooked it up to my receiver and it was powered by the left and right speaker wires.

Passive isn't a bad thing in a high quality subwoofer - it just means that it requires external amplification (and often external EQ). In cheap subwoofers it usually indicates the very bottom of the barrell.