JL 8W7 Subwoofer Enclosure

[Haoleb]

A little background, I have a 8w7v3 driver I use in my truck for a subwoofer, It came with a box when i bought it but I am building a new enclosure for the driver that is tuned lower and built better (the one i have now rattles)

I have been calculating the box size and dimensions and using TLS guys data for this driver I am getting a little confused with some of the measurements on there. First of all Vb is 1.463 cu.ft. and Vtotal 1.898 cu.ft. But I cant figure out where the difference of the two is going? I first thought it was the displacement of the driver which is .06cu.ft. or the port but it is neither.

I have calculated with .75" MDF or plywood I will have .532497cu.ft. displacement from the port assembly which would be a total dimension of 3.25x7.50x37.75.

Mostly what I need to know is what my internal volume of the box should be not including the displacement of the port, driver and braces. I will add all of those before deciding on a total size. I am assuming if I use TLS specs it would be Vb but I am not sure because i cant nail down the difference of that and Vtotal as I explained above.

 

[Haoleb]

Ok i have figured out that Vb is my box internal volume not including anything which is the magic number I was looking for. Off to the depot! Will post my specs and pics as Its built!

 

[lsiberian]

Ok i have figured out that Vb is my box internal volume not including anything which is the magic number I was looking for. Off to the depot! Will post my specs and pics as Its built!

Vb is what really matters. Be sure to put a 4" sheet of rockwool behind the voicecoil. It will reduce mechanical noise significantly.

 

[Haoleb]

Well got the box built! Tested it real quickly with some test tones and I can tell already its going to be a huge step above the other box I had because it doesnt make all kinds of port noise. Its not a WHOLE lot bigger than what I had. although the port is quite a bit longer. Stuffed a pillow in there instead of rockwool or polyfill since it was handy and i already had it. Not perfect i know but yada yada its a truck sub..

couple internal cross braces and a box and a half of screws and a tube of glue. This thing sure isint coming apart.

I will say that even though the W7 mounting is clever and sleek.. What a pain. I got the driver all screwed in very carefully to not damage it.. all 12 screws. only do realize i forgot to put my gasket on it! ARGH!@ take it all apart again very carefully....pick screw off spider with needle nose when it drops inside. grr..

New box and one I got the sub with. Front baffle on the new one is double thickness and the driver is flush mounted (sorta)

 

[Haoleb]

Got a few minutes to test out the new box today. What a difference! All the nasty peaks the old one had are gone and now the response seems pretty flat across the board. All the port noise is gone too. And better yet finally some decent low freq output!

Anyone looking to build an enclosure for the 8w7 I can attest that TLS guy's specs are a good match for the driver. I didnt build it exactly as it was specified but it was very very close. I added a little volume because I wasnt sure what type of bracing I would be putting in it I think i went with a 1.6 cu' box instead of the 1.4*** spec'd

 

[westcott]

So what amp did you go with?

I realize this thread is a year old but I came across it while doing some research. I was thinking of going with the JL Audio 8W7 with an Alpine PDX-M6.

Space seems to be my reasoning for chosing this subwoofer. Any tips would be appreciated.

 

[Haoleb]

Well this is the sub I used in my truck, It came with the JL 500/1 amp when I bought it used and thats what I used to power it.

 

[lsiberian]

Well this is the sub I used in my truck, It came with the JL 500/1 amp when I bought it used and thats what I used to power it.

In your car? I'm afraid I'd break my car if I put something in it. Somehow twin TC Sounds drivers sounds like a great idea only in theory.

 

[Haoleb]

well that little 8w7, while impressive, was not as powerful as the Kappa 12vq in the enourmous enclosure I used to have... That thing was pretty impressive.

 

[lsiberian]

well that little 8w7, while impressive, was not as powerful as the Kappa 12vq in the enourmous enclosure I used to have... That thing was pretty impressive.

No it's not quite a Kappa, but it's also only 4" and let's you port in a small enclosure.