Checking for leaks in ported box?

[JL12W7INAGS300 10+ year member]

I bought a brand new JL12W7 off eBay and a ported box with a 1.5" front baffle, built exact to JL specs, from the same guy. This guy has pretty good feedback (3000+ positive) so I figured his boxes must be alright. After I installed the sub and started playing it I immediatly noticed a leak in the port (where the wood from the port meets the front. I sealed up the holes with a some Shoe Goop (only thing I had around and figured it would work as good as anything). Today I took out the speaker wire terminal and sealed all that up with Shoe Goop. I think there are some more leaks because this sub should be louder than it is now. It is being powered by a 500/1 amp and I am soon getting a 1000/1 to replace that. Whats a good way to check if the box is leaking? Thanks!

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[m98bigshot 10+ year member]

Well first off, is it caulked inside? There should be a white/clear residue on all the joints where the MDF meets. If not, you're definately going to want to do that. BUT if you do, be careful, silicone must cure for at least 24 hours before you can put your sub anywhere near that box. The fumes can be corrosive to the surround.

Next, to check for leaks, crank your system to a reasonable level where it starts putting out some good bass. Listen closely around all the joints, put your ear/face next to the box. This way you can hear and feel any air that may be escaping. I'd definately use some silicone caulk around the terminal cup, thats a tricky spot to seal right. I used a good amount of silicone on mine and it still leaks a little. Hope that helps.

 

[bimma85 5,000+ posts]

Well first off, is it caulked inside? There should be a white/clear residue on all the joints where the MDF meets. If not, you're definately going to want to do that. BUT if you do, be careful, silicone must cure for at least 24 hours before you can put your sub anywhere near that box. The fumes can be corrosive to the surround.
Next, to check for leaks, crank your system to a reasonable level where it starts putting out some good bass. Listen closely around all the joints, put your ear/face next to the box. This way you can hear and feel any air that may be escaping. I'd definately use some silicone caulk around the terminal cup, thats a tricky spot to seal right. I used a good amount of silicone on mine and it still leaks a little. Hope that helps.

//content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif right......

What does the sub sound like? Are you sure you have all your setting correct?

 

[JL12W7INAGS300 10+ year member]

My amp is set exactly as it is specified in the JL manual for a 500/1 amp. The sub sounds good, but I was expecting something a lot louder for a 12" W7 in a ported box. When the weather gets better I am going to find a better place to ground in my trunk, that may also help a little. There is sealent inside of the box, it looks like he used Liquid nails or something of that sort. I thought there was some sort of trick of the trade to check for leaks or somethin.............

 

[Alaxan 5,000+ posts]

Really, if you want to find a "leak" in the enclosure... grab a feather, or otherwise lightweight material and run it along the edges of the enclosure while the sub is in operation. You should be able to see it moving from the airflow over it.

Otherwise, it is possible the port was designed poorly or the box itself and the sub just simply will nto sound like you think it should. Typically, if there is a leak though, you will be able to notably hear the sound rushing out of the said leak.

 

[JL12W7INAGS300 10+ year member]

If I post some pics of hte box up here will you guys be able to tell if it is properly built or not? Thanks.

 

[Alaxan 5,000+ posts]

If I post some pics of hte box up here will you guys be able to tell if it is properly built or not? Thanks.

I would need pics, + exact dimensions for all aspects of the enclosure.

 

[JL12W7INAGS300 10+ year member]

Okay I will do it tommaro once it gets a little warmer outside.

 

[Alaxan 5,000+ posts]

Okay I will do it tommaro once it gets a little warmer outside.

Not a problem! I will keep an eye out on the thread here to see fi I can be of any assistance.

 

[JL12W7INAGS300 10+ year member]

I'll drop you an IM, thanks for the help so far

 

[Volenti 10+ year member]

Another way is to play a tone at the tuning frequency of the enclosure (the point that driver moves the least) this is also the point that has maximum pressure inside the enclosure (more pressure than sealed)

If the box is going to leak it will do it at this point.