Okay, I had a local shop build me a custom box for my JL 10W3v2. I only asked that it be sealed, and the back wall be made of fibreglass and formed to the side of my trunk to take up as little space as possible. Now, I recently upgraded the amplifier from 150Wrms to 250Wrms (both JL amps, the sub does 300W continuous). Since the new amp was installed, I find it very easy to bottom out the sub, and it seems to be missing quite a broad spectrum of frequencies. The internal volume is supposed to be like 0.5 cubic feet and it is closer to 1.25 cubic feet. Could this be the problem. I have a 12W3v2 in another car and the box is made precisely to spec and sounds fantastic. It is running off of the same amp, so I believe that it must be my box.

Any input/help would be much appreciate.

[ November 19, 2004, 02:45 PM: Message edited by: PSIVIC ]

 

If youre box is over double the recommended size then its definitely the problem (unless theres an air leak in your box... but its probably the volume).

One thing you can do it take the sub out and use blocks of wood (or anything really) to take up about 2/3 of a cubic foot of space within the box, then you'll be happy. No need to make a new box. You can just glue them in or screw them down.

 

Hey thanks, I'll give it a shot. At the very least it'll confirm whether the internal volume is the problem.

 

Also check the bass boost on your amp. I see many people that tune there cars improperly and jack the boost(usually centered at 40hz.


1.25 doesnt sound that big for that driver and the power you have [img]graemlins/dunno.gif[/img]

 

Agreed.. the sub should be loving it...

 

I have a remote bass control module for the amp that adjusts the boost, but even if I have it set to the minimum (off), the sub will still bottom out on certain tracks even at low volume levels (i.e. 10 out of 35).

 

http://www.jlaudio.com/subwoofers/10w3v2.html I think that .75-.9 cubes would be a better size for your driver, .5 sounds a bit small. Maybe try to take up some room inside the enclosure, as someone else said. Also, while you have the sub out, check out the fiberglass work inside the box and make sure that it is solid and not too thin. You want to make sure that the shop did a few solid layers so that the enclosure is not flexing, also. Good luck!

 

according to the specs that i have, the optimum enclosure for that sub is .625 sealed
1.25 is not recomended,however,1.25 is the recommended ported volume, with a 3.0 port, 12.2 inches long. can the enclosure be ported? the sub seems to perform well according to their specs.

 

also,a ported box will eliminate the "bottoming out" that you were referring to.

 

^^^ Mike Just beat me to it.
Agreed, port it [img]graemlins/thumb.gif[/img] You won't regret it.