For anybody with subwoofers in their KJ:

I've had 2 12" subs in my KJ for about a year or so now, and the rattles are starting to get to me. I feel like a ricer for having such obnoxiously rattly bass. Obviously dynomat is what everyone suggests first, but the stuff costs a small fortune. Has anyone done anything easier (glue, duct tape, bolts, etc.) to the internal parts (sounds like behind the bumper) to decrease or eliminate the rattles!?

Take the sub's out!

hahah thats never an option!!!! forget trunk space!

Where exactly does it rattle? Spot those areas first, and see if you can stuff something in there like cloths, sponges, etc?

i have a pair of 12"s also if u can.... face the subs towards the roof....it helps ALOT!!
facing them towards the rear gets all that crap rattlin

do waht i do and just turn them up even more

FatMat! Just like dynomat at half the cost!

Here are mine:

Never had any rattle issues with mine.

Have you looked on ebay for a cheaper sound deadening?

I have never used Dynamat on any car I've owned. I haven't put my twelves in my KJ yet but next weekend I will But I'm with you though no bass is a horrible way of listening to music.

The only thing I'd suggest since I dont know what will rattle yet is turn it up and start walking around the rig pin point all your rattles and target them one by one. On my volvo a little bit of (bicycle inner tube) rubber cut to measurements did the trick. My rattles there were the plate and the weather strip on the back window. For my ram the rattles were the side mirrors and back sliding window the rubber worked for those too. My 350z rattles where the gas cap door for that I used silicone from the hardware store. All three ran 12" subs...

Also pointing your subs back gives you the best sound up front. Pointing them up you loose bass as the sound tends to dissipate quicker with no significant rebound. If you ran a bandpass box then pointing it anywhere wouldn't matter it would still sound like crap (just my opinion).

The only thing I can think would tattle on my KJ is the rear window wiper and gas door.

Anyway hope that helps.

Forgot to add the rattles will come from two hard surfaces making contact (I am sure you knew that) so to stop them place the rubber between the area. For the plate I used the rubber as washers on the plate for the Z I used the silicone around the entire gas door since I couldn't pinpoint where it was tapping.

Thanks for all the ideas guys! I should have specified that I could not find the area inside of the bumper that was rattling. I was blasting music in my garage all night, laying on a dropcloth, trying to reach up there haha. Still no luck. I've looked all over the place for cheap substitutes for dynamat, but they're all still pretty expensive. There aren't any external rattles that I know of (wiper, gas cap, plate, etc), but those internal ones are killing me. I shouldn't say that it ruins my bass, but I keep imagining the tight sounding bass I'd get without them. I just think of my KJ as a giant sub box and how good it would sound from the outside!

Do you hear the rattles from the inside of the Jeep or outside? There are some vents in the rear bumper that allow for pressure changes and they will rattle like made with bass. I can only hear them when my kj is parked in a garage though.

Bandpass enclosures sound good (done 100% correctly), dunno why you say they sound like crap; and no matter how they are placed because of how they are constructed, they work great. A bandpass only sounds bad when the AMP is not cut-off correctly. To use a bandpass, the cut-off must be at least 150Hz, anything above that will sound horrible. Also, they require almost 50% MORE amplifier power to drive them, but the bass from them will cause inner ear damage if done correctly... I had one, and it was fantastic. I had a 4th order bandbass, and the base was phenomenal at 125Hz and under, with 400Watts at 200 per side. They are made for specific frequencies under 150hz, and any use above said frequency, makes it sound incredibly horrible.

I personally don't like the sound but like I said a bandpass box "can" be placed anywhere and "can" be faced anywhere. I guess after 10 plus years of sound systems I just grew accustomed to a sealed box. Didn't mean to offend anyone they just aren't for me.

I see you have the Silverstar Ultra high performance bulbs, how do you like them?

i dont care 4 bandpass boxes either. they are not very accurate. actually they dont NEED a crossover as their design cancells out frequencies above 150 htz or so. but they will sound better with a crossover .and they are very efficient and play loud without a ton of power.

i also prefer a sealed enclosure. i have tried facing my subs towards the rear and noticed very little diffrence in sound . except added vibration.

also ...stuffing the hollow parts in the rear area with polyfill will help with vibrations.

Dude, I used it without a crossover (cut-off), and I can tell you, it sounded like total crap. They are NOT designed to automatically cancel out the frequencies, if you read the directions that come with them, how to hook them up, like MINE DID, it said specifically to use a cut of off 150Hz or lower. I wish I had audio of it, because it really REALLY sounded bad without the cut-off switch ON, and dialed in at 125Hz. You try it, and you will see what I mean; it's awful.

See mine here: http://cloud.prohosting.com/davenger/avgallery.html
go down to "My Sub-Box"



The 4th order bandpass is basically a speaker or speakers, placed in a sealed box with an identically tuned port (or ports) on the other side of the sealed section(s). Its transient response is second only to the sealed enclosure systems, making it a good choice for subwoofer applications. Without a low pass filter, there will be some out-of-band noise present. Use a low-pass built into an amp, as running one in series with the speaker(s) effects in-band response of the system.

The way mine was, it had 2 12" speakers at 45 deg angles facing each other, and a Plexiglas front, the SEALED portion. On each side, there were 3 3" ports, that I didn't have to tune, it worked great with the speakers I put in. The specific name of mine was "Folded Horn bandpass enclosure," but a 4th order type.

2nd order are SEALED boxes.
http://www.the12volt.com/caraudio/boxes.asp