Hi, My subs have been sounding like crap for a long time. I am convinced it is the box , but i can not easily hear a leak. The subs just sound boomy and aren't really moving very much. They sound like they're reverberating at high volume rather than hitting, and really don't move much. They push in and out smoothly by hand and seem to be fine. I recently turned the subs slightly and drilled new holes, not filling in the old ones. This made it worse, and now they sound worse than ever, but I still cannot feel or hear a leak.

If the old holes need to be filled, what is the best way to do this. Also, I have no poly fill in this box, and it is 1.15 cu. ft. per chamber. The subs are in my sig.

 

Well, if anything, an air leak would make the subs move more and not less.

Sounds like maybe you might have another issue on your hands. Might want to hook other subs up to the amp and see if it behaves the same, if it does than maybe your amp might have issues. I dunno, just a guess on something to try.

Tip on finding air leaks, use a cig. and move it around the box after you turn it up and watch to see if the smoke moves around or not.

Ted

 

How big of a box is recommended by MB Quart for those subs? If the box size is within spec I wouldn't worry about poly fill. If you need to put some in go to a place like Wal-Mart and buy some of that pillow stuffing and put some in there. Make sure you don't pack to much in there, just enough to where it's in there and is fluffed (sp?) up. If it's packed in their too tight it will do more harm then good.

HTH!

Ted

 

Fiberglass resin or regular ol' liquid nails.

 

I just read that the reccomended box volume for my subs is .77 cubic feet. I am pretty sure my box is in the 1.0 to 1.2 cubic foot range per chamber. It's a standard R/T Enclosures Sealed Dual 10" hatchback box. I originally bought it at Best buy for $70.

Also, I still have my old 12" Fosgate HE2 DVC sub sitting in its box, which I know for a fact leaks, and I can hear a squeaking air noise when i push that sub in and out. I can't hear anything when i push my MB Quarts in and out mounted in the box. They take about 2-3 seconds to return to their original position after I release them.

I have heard that my subs sound best Ported, does that mean that they should sound bad sealed?

I have a few other amps i could try, I'll see if any of them make a difference.

To respond to your other suggestion about the amp possibly having problems. I tested my old fosgate out. It hit harder than the two MB Quarts even leaking all over the place but still acted the same way at high volume.
I had to turn the gain way up to get any output out of the fosgate, and i have had the variable bass boost at 0 since day one.

 

You should be okay then, I'm sure they can handle a box a little bigger than the recommended size. Be careful not to overpower them and if it sounds like they aren't liking how loud you have them back it off some.

I wouldn't use poly fill though in your case, it's not needed when you are giving the subs plenty of air space like that.

The speaker should just bounce right back after you release it in a sealed enclosure. Having it take time for the sub to come back is a sign there is an air leak somewhere. If the box is sealed up pretty good when you push in the sub you are compressing the air in the box some but if there is a leak when you push in the sub you are pushing air out of the box and the 2 to 3 seconds it takes for the sub to come back is the air going back into the box. Check around it for airleaks if you can with lite cig. and you should be able to find it by that way of going about it.

Hmm, well, most subs on the market today for car audio can work in both ported and sealed set ups and I'm assuming these subs are the same. I would say that overall they should work just fine in a sealed enclosure but if I get time later I'll look your subs up and look at the specs and see what they would work best in. Like I said, I'm pretty sure they will work in a sealed enclosure just fine.

HTH!

Ted

 

Thanks for the reply.
Well, I don't smoke, so the cigarette method isnt going to work. I'm not going to bother testing, when i have 8 screw holes on both sides with no screws in them, in addition to the 6 holes the subs are using. I'm sure if it's leaking, it'll improve once i fill those holes.

I found an old 12" box with no extra holes, and put my old Fosgate HE2(RFP2210) DVC in it. This sub hit harder than my MB Quarts ever have, and just ate up the power. This box looks like it might not even be MDF. It is only 1/2"thick, is much bigger than my single 12" Q-logic box(the leaking one), and weighs about half as much. I would just keep using this sub, but I don't particularly like the sound of RF.

Theres one other thing. Are terminal cups supposed to be glued in? My box came with them just pushed into the holes, they werent screwed in or sealed in any way.

 

build a new box...

 

If this wasn't a $70 box i'd probably just do that. It's pretty funny that a hollow $30 generic box sounds better than this expensive box. Atleast I know not to touch anything made by R/T enclosures ever again.