any suggestions on a really good boomamajigger aka subwoofer thats non powered that i can splice into my system , that i can also get or look for used for under 40 bucks tops.

( keep in mind i have a free sound system i scavenged parts from around my area so its nothing special just something to rattle some pictures off the shelf )

i think i have a 3 ohm sub and i know goggle is my friend but i wanna talk to people for once im tired of the robotic generic information returns .

 

Car subwoofers often get dumped for an even more insane model, so these might be the best bang for the buck. If you're lucky, you can even get one free from a car hifi nerd friend

 

Most powerful is really the wrong attribute when searching for speakers.
For making your pictures rattle I suggest a jackhammer.

 

yeah speakers don't produce power, they convert electrical energy into accoustic energy. The power ratings they get are a sales technique. All that figure means is it can dissipate the heat generated when said power is put through them. It may not be able to produce the sound cleanly though.
Look for efficiency (sensitivty). A more efficient speaker / woofer will sound louder than it's counterpart when reproducing the same signal.

What size room is it going in? I had an 8 inch logitech sub i picked up from a pawn shop for $20 when i first started and it sounded great in my little bedroom (3m by 3.2m)

 

A sub woofer without an extended range long throw driver and a quality high wattage amp (relatively speaking) to push it--- is probably not going to be very satisfactory . Need a good crossover, too. Most self powered speaker set ups use class D amplification to save weight. I'm pretty sure this one will get you some richter scale bowel shaking. Put about a 350 Watt RMS amp on it. lol http://www.jblpro.com/www/products/portable-market/jrx200-series/jrx218s#.VcIdR25VhBd

 

Last edited: Aug 5, 2015

Like mentioned before here, car subwoofers are probably the cheapest answer for you, search for ex. JLaudio, JBL, Lanzar..