mindreaper

iTrader: (1)

Here are some pics of the system on my '99 Z28, featuring Focal 165KP front speakers, an Audison LRX 5.600 amp (bridged for the 165KP), a JL Audio 10W3v3 2ohm sub. I won't show the head unit as it's a crappy one, but it will be replaced by an Alpine.

Here you can see the amp rack and the stealth box I've made:





The tweeters of the 165KP kit were mounted on the pillars:



The woofers from the same kit (note that I've removed the felt from the grilles):



The stealth box being made. It's built of 1/2" MDF to give a maximum of inner volume, and also to reduce weight:



The amp rack is built out of 5/8" plywood (lighter than MDF, the screws hold better), with the top of it in 1/2" MDF:



Here it is covered, with holes drilled for the cables:



Dynamat Xtreme was used for the doors:



I've cut this shape out of 1/2" MDF to fill the hole in each door. The edges of these pieces were then covered with Dynamat for a better seal:



The hole of the window rubber stop, at the bottom of the door, was also sealed with Dynamat. Note also the Dynamat on the inner skin of the door (only about half of the inner skin is covered), as well as the acoustic dampening material from Focal (just behind the speakers):



I've cut this shape out of 1/2" MDF to replace the plastic speaker pods. I was originally planning to keep the plastic pods, but a local car audio expert (he builds show cars for car audio manufacturers) advised me to go for the MDF:



The screws I used for the woofers:



Note that Dynamat was added around each MDF piece, in order to make it as sealed as possible:



Sanding the felt of the speaker grilles (I don't know whether that helps or not, but it's a free mod, so...):



This is part of my older system, currently not connected to anything. I could hook it up to a second amplifier but I don't think I will, as I'm already very happy with the sound I have:



I used up my Dynamat bulk pack in the trunk well:



I listen mostly to trance and I'm very happy with the sound I have!

If you have any questions, comments or suggestions, don't hesitate!

02Z28LS1

iTrader: (2)

lookin good

just a couple of suggestions:

1) paint the heads of the bolts that hold in the speakers in the front doors and the MDF trim rings black....they show through the grille too easily with the black material removed

2) unless it was done for functional reasons (like t-top fitment or adding more components later), i'd center the amp on the amp rack, with one passive x-over for the component set above it on each side of the "hump"....i'm kind of a symmetry freak like that


also, i wouldn't have worried so much about the tiny amount of air space you would have lost with the thickness of the MDF....i'd have gone with at the VERY least 5/8" MDF, but preferably 3/4". if the walls of the sub enclosure flex, you're robbing sound output. and trust me, those JL speakers can definitely make the walls flex with only 1/2" MDF in it. if nothing else, lay down a thin layer of fiberglass mesh and resin to add strength....it will also help to seal it off really well. you could also cut a square/rectangular "ring" of MDF to fit inside the enclosure to add bracing to the walls some, without losing a whole lot of air space. then fill it with poly-fill to "trick" the sub into performing as if it were in a larger enclosure

mindreaper

iTrader: (1)

02Z28LS1: Thanks for the suggestions! I haven't noticed any flex on the box but then again I haven't really pushed the sound up (it's still in break-in). I thought it wouldn't be much of a problem because of the small surfaces and also because the box's complicated shapes give it rigidity. But once the sub is broken in, I'll run it with the grey plastic trim piece off, and I'll see if I can see any flex. If flex does occur then I'll probably go with the MDF "ring" idea

KEE AUDIO

iTrader: (65)

Nice job!! I wouldn't worry too much about a W3 flexing anything. If it were a larger sub like an Fi, or RE that have a much larger motor structure and magnet I'd worry more about it mainly because they weigh alot more.
I completely agree with the painting of the bolts and mounts. I removed the felt onmine as well. I always paint mine flat black or use a rubberized coating for even more sound deadening. I use Performix brand Plasti Dip for this. I coat most of my mounts with this and it dries a nice flat black and has a nice rubbery texture. Comes in a spray can to or you can buy a regular can to brush on for larger projects.
Great work!!

kmgsix08

iTrader: (17)

That's a really good good. post up some pics of the sail panels when you get a chance. i would love to see how you finished those out for the components in the backseat. also, how do the tweeters sound in the pillar?

mindreaper

iTrader: (1)

Thanks for the nice words and the tips! I never noticed the shiny screws until 02Z28LS1 pointed them out but now they bother me! haha Strange I didn't notice it before. I'll paint them flat black next time I remove the door panel, and I'll also investigate the Plasti Dip product.

mindreaper

iTrader: (1)

Thanks! I haven't finished the sail panels yet, still unsure about them. That's one of the reason I left space on the amp rack for maybe an other (smaller) amp. Gotta say though that I'm pretty satisfied with the sound as is (with just front speakers + sub). Maybe it would sound even more awesome with the sail panels speakers connected, this I don't know.

The tweeters sound great in the pillar. They're not too much in your face, which I was a bit concerned with considering the Focal tweeters are very bright.

italicizedsponge

iTrader: (3)

isnt that a W7 in the box?

mindreaper

iTrader: (1)

No that's a W3v3, they look different from the older W3v2, and more like the W6 / W7 (no big JL logo).

KEE AUDIO

iTrader: (65)

JL made the W3, W6 and W7 all look similar in the newest versions. Big difference in them when you turn them around on the other side!! LOL!!

MeentSS02

iTrader: (11)

What thickness of MDF was used in the doors and on the sail panel? Do you have a preferred source for it as well?

02Z28LS1

iTrader: (2)

you probably won't be able to "see" the flex, because of how fast the speaker's cone is moving....but with only 1/2" MDF, you will almost certainly have sidewall flex once you crank it up, assuming a completely airtight seal.

i'm not talking about the weight flexing the box, i'm talking about the air pressure causing the sides of the box to flex.....W3v3's have more than enough cone travel to cause the 1/2" walls to flex when compressing the air inside, assuming the box is sealed well enough.

if it's not sealed well enough, the box may not flex, but the air leak will cause some loss of output as well, so either way is bad.

the 10W3v3's owner's manual even states:

Urban Legend

iTrader: (5)

Everything looks great.

mindreaper

iTrader: (1)

1/2" MDF. What do you mean by prefered source?

Regarding the thickness of the MDF for the box, I asked one of the top car audio guys in Belgium and he said 1/2" MDF would be OK for such a small box with such shapes. Different opinions I guess. I presume thicker MDF is always a little better but then again it robs a little inside volume and weights more. Well I'll see for myself once the sub is broken in, thanks in any case for the input

MeentSS02

iTrader: (11)

Preferred source = where do you get it? I haven't shopped around much, but the only MDF I could find easily was at Lowe's, and came in a huge sheet. Not a huge deal, but I most likely won't need that much of it. I was wondering if you could buy it in smaller sizes somewhere...

samson_420

iTrader: (1)

That looks wayyyyy clean. There is no way in how hell I would take that much time to do all that work. But, it sure does look damn good.

mindreaper

iTrader: (1)

I went to a local DIY store, the smallest MDF sheets they had were about 4 x 6 feet. But then again I live in Belgium, this might be different in the US.

KEE AUDIO

iTrader: (65)

I pick it up at Home Depot in 2' x 4' sheets. Unless I'm building a big project or something that has alot more to it. When I'm just getting it for stealth enclosure faces I get a 2' x 4' sheet of 3/4" and I can get 4 faces from each piece. I thought Lowes had it in a bin as well that was precut into the same size as well. They have 2' x 2' pieces as well in all different thickness all ranging from 1/4" to 3/4".

02Z28LS1

iTrader: (2)

1/2" is fine....if you have bracing in place....but without any bracing when using 1/2" MDF, you're going to get some flex and loss of output with a JL 10W3v3 at high volumes, especially with the deeper bass notes

Lickeyman

iTrader: (1)

Do you have the measurements for that box brother? I want a stealth box but don't want to sniff fumes for glass and have some leftover mdf so if you have those measurements it would be super mega awesome....... Amp rack too if you got it.... LOL I'm soo lazy....

Looks clean and nice attention to detail but yeah paint the screws.

I wouldn't worry a whole bunch about the flex of the box with the thinner mdf. I have personally seen many a box made out of it in tight spots and unless you have large surface area panels usually there WON'T be any probs unless your running a nasty sub and serious wattage. I plan using 1/2" But then again I'm running a 5 year old 10" and 500 watts.