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View Full Version : 4th order lid vibrating.



srb
07-18-2012, 11:43 PM
I have braced the inside and screwed everything down, but the top of the 4th order still vibrates like crazy. It makes a horrible sound of the mdf slapping together.

I didn't glue it down because I wanted to be able to take the top of to check out the subs if there was anything wrong with them, and it was such a tight fit into the trunk of the car, there is no way its gonna come out again. The box was built to the max dimensions and it took five people to get it in.

What can I do? Is there any way I can stop the top flexing from the exterior of the box? Has anyone had this problem before?

I Like Waffle
07-18-2012, 11:57 PM
Had a similar issue with some MDF bracing breaking loose, use a long piece of 3/8 threaded rod and nuts/washers on the inside/outside to keep it stiff.


http://sphotos-b.xx.fbcdn.net/hphotos-snc7/s720x720/391633_217807501626307_2050467784_n.jpg

srb
07-19-2012, 12:02 AM
That's a good idea. But I was really hoping there would be a way to hold the lid down without having to take the whole box out again, if that is even possible.

Decipha
07-19-2012, 12:19 AM
it appears as though bp boxes are more common than i thought, i too just built a 4th order this past weekend for my subs

can you double up on the top board?

RangerDangerV2
07-19-2012, 12:21 AM
double baffle.

srb
07-19-2012, 12:32 AM
I cant double baffle the whole top as it is literally touching the metal on some parts of the trunk (I made a trunk wall). I guess I will do some more testing tomorrow to find the areas it is flexing most and try and double baffle it as best I can.

RangerDangerV2
07-19-2012, 12:34 AM
I would re do it. and design it with double baffles all around.

Mitch86
07-19-2012, 12:39 AM
Ghetto rig it with some ratchet straps? :laugh:

srb
07-19-2012, 12:40 AM
I don't want to have to re do it. I just spent $60 in mdf on the thing, and 2 days building it. I would rather try and pull it out and re-brace it all.

Fi-brations
07-19-2012, 01:05 AM
duct tape...but seriously u may just have to redo it, but post some pics up so we can get a better grasp of what options u have

RAM_Designs
07-19-2012, 01:33 AM
Foam weatherstripping between the panel and box. I would have assumed you already did something like this to have an actual air tight seal.

srb
07-19-2012, 10:54 AM
Foam weatherstripping between the panel and box. I would have assumed you already did something like this to have an actual air tight seal.

No I didn't do that. I was going to tape around the seems using foil tape to make it air tight. That seems like to would work through. That way the mdf isn't just slapping against itself.

And @Mitch86 I have been seriously thinking about ratchet straps honestly....

mazdakid
07-19-2012, 11:34 AM
I use a strip of stick on foam weather stripping on the lip where my removable piece sits.