Price Paid:  $50.00 from pawn

Summary:
This is an addition to my review below (tantric33). I have had a little more time with this sub. The bass was definetly muddy. I took the following action to try to clean it up a little. First I stuffed the cabinet with alot of insulation filling almost half the box and semi closing up the port so it would act more like a sealed enclosure (more efficient). I also placed it on 2 large cinder blocks and placed it in the corner of the room. In addition to these tweaks my room has been pretty heavily treated with John Rischs' absorber room treatments. In general the bass cleaned up a bit (still not so great). For music this sub is terrible but for home theater it works pretty good where only blurbs and LF sounds and a little vibration is necessary. I will upgrade all my speakers eventually but for now it's all good for $50 !

Price Paid:  $50.00 from Pawn

Summary:
I haven't had this thing but a day now but have been pleased so far. I think that people's opinions of brands like Radio Shack are influenced a great deal by the brand name itself. Having worked with car audio subwoofers of various types and brands I picked the Optimus based on how it was built, price and wattage. In a car a subwoofer requires a great deal of power to be heard from the trunk. 100W in an average living room is pretty sufficient where the ambient noise is pretty low compared to a car. This sub rumbles the floor a bit. As for the build quality. It seems pretty good. The driver isn't that big and the weight of the box and amp seem to keep it pretty stable. If you put your hand on the enclosure you'll feel that it doesn't resonate all that much which to me means it's sufficiently mass loaded (which is good) The price: well it's freakin cheap ! As for the complaints of muddy bass I am not sure on that yet. Are you listening to the sub on its own ? A sub requires the main speakers to make it sound smooth. A sub on its own will always sound like cr*p. So far so good for me. Recommend it if you can get it under $100 for sure and don't have an enormous room. Place it in the corner for sure.

Strengths:
Price and gets the job done

Weaknesses:
Could have a more substantial cone, more mass on the enclosure (add this yourself with anything that's heavy)

Similar Products Used:
MTX, Lightning audio, infinity, memphis audio and others

Price Paid:  $150.00

Summary:
I have had this sub for a while now (2+ years). In its factory form, it’s very muddy/boomy/poor sounding unless it is on VERY low setting. Just running it on a low power setting was "ok" while I had low end speakers but I just bought a Bose center and am going to be upgrading the FR/FL to the Bose ACs VERY soon and the RR/RL will soon follow. With this, I demanded more clarity out of the sub. This weekend I went and removed the port, covered it with some 3/8" plywood (sealed the box), and stuffed it with 1lb of poly fill. While it’s still not “perfect”, it is A LOT better (comparable to a $300+ sub). The "boom" is gone and it blends much better with the rest of the system (more musical). In tuning, I found that if I run the crossover up to 150Hz and the volume down a bit, everything blends VERY well. This “hiss” from the amp is still there, but it is inaudible unless I put my head up against the driver its self so I can’t complain about that.

Strengths:
cost, easily fixed/improved to sound VERY good

Weaknesses:
muddy sounding bass

Price Paid:  $150.00 from RADIO SHACK

Summary:
I FOUND THAT ADDING SOME POLYFILL ABOUT 1/4 OF THE CABINET AND PLACING THE UNIT ON A 12X12 CERAMIC TILE INSTEAD OF DIRECTLY ON THE CARPET SINCE IT HAS THE PORT IN THE BOTTOM
MADE THE SUB SOUND MUCH BETTER. THE HIGH QUALITY CABLES ARE
A MUST TO ACHIEVE THE QUALITY SOUND YOU ARE LOOKING FOR FROM
THIS SUB.ALSO SETTING THE CROSSOVER BELOW 60 HZ APPROX. 55 WORKED BEST FOR ME. THIS IS THE RCA PRO-SW100P SAME AS THE
OPTIMUS.

Strengths:
PRICE

Weaknesses:
SEEMED MUDDY LACKED TIGHT BASS

Similar Products Used:
NONE

Price Paid:  $125.00 from Radio Shack

Summary:
I bought this thing knowing it was a total POS because I wanted a commercial looking cabinet with a small built in amp. There is no way I could find a cabinet and amplifier for less than 120 bucks so I bought it. I had an old JL Audio 10W4 2 Ohm Car sub and a 3" flare port and I installed it. It sounded pretty dang good. Infact it sounded better, louder, and deeper than my Paradigm PDR10. I turned around and sold it for $350 bucks to someone who had to have it.

Strengths:
It looks nice

Weaknesses:
Very muddy sounding bass, Very poor quality woofer and amplifier.

Similar Products Used:
Paradigm PDR-10