Please help subwoofer making awful noise

[David Stone]

49x17x23.5 7.5 wide port. 3/4 mdf with 2x2 braces. Tuned to 32hz or so. just over 7 cubic feet which is what JBL recommends (3.5 per sub)

It is in the back of a 2005 Club cab Dakota facing up.

[Ahmed Johnson]

It'll probably be best to post a video of them playing. I know you aren't running the most power but you need to brace that box up, it could be the wood slapping each other from flexing.

[reedal]

Just a thought, because a guy on the ship with me has a noise coming from his sealed prefab, I knows yours isn't a prefab but if the glue used to build the box has separated a connection of the boards, it might give it enough flex to cause an air leak and excess vibration = noise.

Just a thought. Another possibility is, you have a single baffle? If so, maybe the weight of the subwoofers has weakened/cracked/broken it.

A couple ideas, since they seem fine free-air, the enclosure seems to be the only other component to cause that noise.

[Triticum Agricolam]

Have you tried pushing on all the different sides of the box while its playing and see if the noise stops? Kinda along the lines of what reedal was saying, if a glue joint came loose somewhere you might be getting some funky panel vibration.

[David Stone]

I just went out and pulled both subs and twisted them a bit and rescrewed them down with new holes. Seemed to have helped a bit. How much more should I brace it? Maybe just add a few more side to side braces? I have two running up and down and one side to side at the moment and they are glued together where they meet. I could run a side to side under each sub. What do you think?

[SIDE SHOW]

i'm guessing its the box or a panel in your car making the noise (specially if it only does it at higher volume)

[David Stone]

Honestly I could add braces for a few bucks but if that does not fix it I may just build a simple sealed box for them. They do well in 1.5 each sealed and that would free up a ton of space. I just don't think I can do all that work again with the ported box. I live in an apartment and getting cuts done is a pain in the ass.

[David Stone]

This all started out of nowhere one day when I was really laying into them after breaking them in for a few weeks. So if some glue come undone would the screws not hold it in place? There are screws about every 4 inches along all the boards.

I appreciate all the feedback and suggestions guys. This is only my second ported enclosure build after I built one for an E-8v3.

[Joe X]

Cover one of the cutouts with some MDF and test one sub at a time, if you get the noise in both cases then very likely is not the subs but something loose in the box.

[David Stone]

So I figured out what the problem was/is. The screws holding the sub keep working their way loose. I rotated the sub and put in all new screws and it solved the problem for a few days but again today I laid into it a bit and the vibration started again and I had to tighten a few screws. What do you guys recommend to fasten the subs to the baffle? I would really like to stick with screws of some sort and not bolt just because I can't (pretty hard) remove the box to work on it. Should I fins some thicker screw or wood screws. I am currently just using the same drywall screws I used on the enclosure. Thanks again.