[LoneJeeper]

I'm looking to make use of the 'secret compartment' area for a sub and a storage box. The drivers' side is less roomy (with the filler neck in there), so that's where the sub is going.

I'm basing this project from a mix of


http://www.oman4x4.com/gallery/sub/speaker3.jpg
http://www.jeepsunlimited.com/forums/showthread.php?t=281405
and


http://www.jeeps4ever.com/Jeepin_Rock_Climber/storagebox/Jeep%20TJ%20Storage%20Solution_files/image002.jpg
http://www.jeeps4ever.com/Jeepin_Rock_Climber/storagebox/Jeep%20TJ%20Storage%20Solution.htm
anyway, what I need to know is, would it be more worthwhile to try to build a sub box out of MBF, and durabak the outside (for moisture) and not port it for my 8" sub? OR should I just bolt it up like it is in the pics?

thx

lj

[HootenTJ]

I think if you don't have a boxed enclosure for the sub it won't do anything but rattle, and not the good kind. You HAVE to have an enclosure for a subwoofer or it's pointless, there's nothing for the sound waves to bounce off of, except the metal tub which will sound awful. Every sub NEEDS a boxed enclosure.

[LoneJeeper]

ok, so will a 9x9x4 metal box with dynomat and/or polyfil be sufficient? will it need to be ported?

lj

[HootenTJ]

Originally Posted by LoneJeeper

ok, so will a 9x9x4 metal box with dynomat and/or polyfil be sufficient? will it need to be ported?

lj

I've never heard much success with metal boxes, I've only made em out of MDF. And as for ports I'm not the most knowledgeable on those so don't take my opinion. I'd just make a completly enclosed MDF box for the sub, not sure how it'll do tucked inside that opening you plan on making.

[SirGCal]

The metal would have to be pretty thick and reinforced to not resonate, even with dynamat, the pressures of subs will flex thin metal. I also use MDF only (5/8" minimum, 3/4" or larger usually). In the case like what you're thinking, I would still build an MDF box then layer the outside with fiberglass or bedliner to protect it. But still, that is not a very stealthy approach and using that type of a setup decreases the value on the vehicle (body mods like that always do) and changability later. Plus you still can't put something in front of them or they will sound worse.

Do you still use your back seat? If so, there are other options for no-storage used sub systems that do not require hacking the body. One of them being the in-seat option. I have plans for all year TJs to date on my website. The only catch is picking subs that will fit the box. The small 97-02 box and 03+ box have a shallow depth limit. For 10" subs, illusion audio or earthquake SWS work very well. For the new large 97-02 box, a pair of JL 8W3v2's were designed for it but also the added depth makes conventional subs possible also. All plans and steps available for free on my site.

Other options include a false floor (not recommended) or a console mod (but still lose the console storage).

Porting is not recommended in any of these small-box ideas because a ported box normally requires a lot more internal volume than a sealed box for the same speaker. Plus you have to tune the port and box to the vehicle and for first timers this is very difficult and will often sound a lot worse than a sealed box. Plus, ported sound is different than sealed so it might not be the sound you are after anyhow. I myself prefer a good sealed setup over even a good a ported one for my listening preference.

[LoneJeeper]

SirGCal, as always, worth his weight in gold.

I'm not looking for it to win any competitions, and could care less about resale value... i guess my question is, how bad will the sound be?

lj

[98JEEPTJ]

The only thing that comes to mind would be to get it to the biggest volume possible then use 1"x1" wood stock to create a frame around the inside of the opening to screw to then Fiberglass the five sides and the pieces of wood then get a piece of 3/4" MDF for the sub to mount to cut hole mount sub then screw into the frame you created you are going to want to seal the face board on all the edges. You would have to find a sub that would work best with the volume of space you have. Look for the sealed box dimensions. Probably a 8" sub or a 6" I don't think there is enough volume for a 10" but could be....

[SirGCal]

Originally Posted by LoneJeeper

SirGCal, as always, worth his weight in gold.

I'm not looking for it to win any competitions, and could care less about resale value... i guess my question is, how bad will the sound be?

lj

The sound will not be too bad if done right. Actually it could reinforce with some corner loading to get quite a nice sound from it. I personally would only do one corner if I was going to do it to avoid possible cancelation from direct impact waves (subs firing at each other can sometimes cancel each other).

The biggest catch I do not like about it is you still lose storage. (you can not put something directly in front of the sub without losing effect. And the side-firing setup relies somewhat on the corner loading for it's responce effect. (corner loading happens in the opposite corner) So from that point of view, you still lose storage space. But if that temporary sound loss is no problem then there is nothing bad I guess. The only other thing is the subs are still easily visible from outside and could potentially be vandalized or stolen. But asside from those things, that setup could be done very effectively.

Other possible negatives, you lose the possibility for a comp-cut later on without removing the box again. Something I just thought of since I myself want a comp-cut. You can also lose some flexing room depending on the suspension you run and specifics of the design. Lastly, it is not something that can be easily undone if you decide to change it... Just things to consider.