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subs in xjs

Anyone know a good location to mount the amps ?

kickercomp009.jpg
 
No pics handy (can't see them right now anyhow - too many lawnmower parts in there...) but I've got an old Kenwood 450W amp driving a Rockford 10" driver in a wooden tube. I've got straps done to hold the tube down, and I've rigged a pair of bulkhead banana jacks so I can pull the thing when I need to.

Since I only need a sub for low-end fill-in (gives a fuller sound, I think,) so I don't need much - but does anyone know where I can get wooden tubes for 10" drivers? I've got another Rockford (picked up a pair, cheap!) that I'd like to get an amp for and put in my wife's truck...

5-90
 
I'm running 2 10" MA Audio's in a sealed box, powered by an MA Audio monoblock amp rated at 1600w max at 2ohms. More than I really need, but I only paid $300 for it and I got half of that from selling my old amp and subs. No pics since you can't really see any of it. Amp under rear seat, subs covered and in with my toolboxs, spare tire, spare parts, etc.

camarors8992 said:
Anyone know a good location to mount the amps ?
Under the rear seat, on the sub box, on the rear floor, on the back of the rear seat, on the headliner(best one I've seen yet!), etc. Is is that hard to find a spot?
 
camarors8992 said:
Anyone know a good location to mount the amps ?

kickercomp009.jpg

Under the back seat is where I would go with it. I put one in my ex's ZJ there, and never had a heat issue with it( It was only about 250w RMS though). As you can see in mine it's where the factory spare was.
 
My new box is designed, cut, assembled, and test fitted. Just needs weather sealed, speakers wired, caulking and reassembly, hardware for cargo area access attached, some gray carpet, and solid tie downs. Birch Ply this time, used two sheets so I'd have plenty to spare and for another idea I have in mind. I found some at Home Depot (second store I went to) for suprisingly not much more than MDF.

Birch Ply vs MDF in my experience

pluses
Birch holds screws like wood (MDF is like old pudding)
Birch is more forgiving of drilling angle accidents:sad1: (MDF tears up easy)
Birch smells like wood (MDF smells like something)
Birch is stronger while quite lighter (MDF heavy)
Birch looks like wood (MDF looks like leftover sawdust, I'll cover it anyway)

minuses
Birch outer surface layer peels a little bit during drilling, cutting, handling
(i'll cover it anyway)
Birch is more expensive

Whats a good speaker wire to use?
 
xjblue said:
My new box is designed, cut, assembled, and test fitted. Just needs weather sealed, speakers wired, caulking and reassembly, hardware for cargo area access attached, some gray carpet, and solid tie downs. Birch Ply this time, used two sheets so I'd have plenty to spare and for another idea I have in mind. I found some at Home Depot (second store I went to) for suprisingly not much more than MDF.

Birch Ply vs MDF in my experience

pluses
Birch holds screws like wood (MDF is like old pudding)
Birch is more forgiving of drilling angle accidents:sad1: (MDF tears up easy)
Birch smells like wood (MDF smells like something)
Birch is stronger while quite lighter (MDF heavy)
Birch looks like wood (MDF looks like leftover sawdust, I'll cover it anyway)

minuses
Birch outer surface layer peels a little bit during drilling, cutting, handling
(i'll cover it anyway)
Birch is more expensive

Whats a good speaker wire to use?


Helpful tip for "appearance grade" plywood - apply a good masking tape (I like the 3M "blue" tape) over where you're going to drill to keep "surface pull-up" down. A couple layers certainly won't go amiss. Ditto cutting (use a sharp saw, preferably fairly fine teeth) and smaller bits can be wrapped in paper for handling when appearance is critical...

MDF looks like sawdust because it is sawdust - mixed with glue and rolled into sheets. That's also why it's so damn heavy - it's rather denser than plain wood, and the glue that holds it together is even denser (and there's more of it than in plywood...)

Principal advantage? I believe that MDF is easier to "steam and shape" into true curves, and it's cheaper because it starts life as "mill scrap."

5-90
 
5-90 said:
Principal advantage? I believe that MDF is easier to "steam and shape" into true curves, and it's cheaper because it starts life as "mill scrap."
For sub inclosures, the biggest advantages would be uniform consistency of material, resistance to vibration, and more of an air tight base.

The uniform consistency of MDF helps it to retain it's shape better than normal plywood. Normal plywood will expand/contract at different rates throughout the ply's, causing it to warp. Because of the uniformity of MDF, it tends to expand/contract at a much more even rate, allowing it to hold its shape and resist warping.

Normal plywood doesn't hold up nearly as well to the vibrations and pressure from even small "systems." When a speaker or sub is firing, its creating pressure, both inside and outside the enclosure. Plywood can delaminate due to vibrations (which can easily happen over time), affecting the longevity of the enclosure. Also, plywood will flex more, "absorbing" some of the pressure that the woofer would build inside the enclosure. Any pressure lost inside the enclosure through flexing or an un-tuned port (in ported enclosures) will diminish the overall output from the sub, as well as affect its sound quality.

Normal plywood is not airtight as most would suspect. While it does resist air passing through, it does allow some movement through. When MDF is created, the addition of pressure over the surface with excess glue creates a "skim" over the surface which is airtight. If the enclosure is properly sealed on all the internal seams, then the resulting encloser is much closer to a sealed container than a plywood box would be. How well sealed the box is also affects both the quantity and quality of sound, as I mentioned earlier about the flexibility of the enclosure materials.

These properties together in MDF help to achieve better performance and acoustics. Then again, the fact that it's cheap is a pretty good benefit too...

Sorry for the full essay, just wanted to put in my .02 ...well .03 at this point.:confused1
 
xjblue said:
Whats a good speaker wire to use?
I'm not an expert, but lots of people in the audio forums go for knukonceptz.com I didn't run any tests or anything, but visually, their speaker cable appears to be of a higher quality than monster cable, and it's cheaper to boot. Their battery terminals are a bit spare, but functional and cheap, and I've read one or two accounts of people who felt underwhelmed by the distro blocks. Fast shipping and customer service though.

I tend to believe the group of thought that says a wire is a wire, and once you match stranding, and gauge, the rest is all fluff. Then again, I can't tell the difference between a 192kb mp3 and a CD, so any differences would be lost on me anyway.
 
994x4xj said:
im having a 8'' sub installed inside of my center consule on my 99 xj
do you have any pics
 
good info... I'm no audiofile but know enough not to argue against the accustical benefits of MDF. Birch ply did look like the best type of ply in the store for whatever thats worth.

I found some nice looking 14 gauge speaker wire at Wal Mart of all places.

Here is a shot from late saturday nights first assembly and test fitting.
P8070039.jpg


Found a big problem yesterday (my bad measurement) and spent another late night fixing it, wiring the speakers, and sealing the box, thought that was all taken care of but then had to pry off the lid and reseal/remount it correctly again (my friends lack of attention to detail). Thankfully the birch ply was more error friendly, we felt like everything that might go wrong, did go wrong.

Wired in the ol' amp, threw in the new deck, and WOW. Our new design kicks old design in the hind quarters several times over. With the subs bridged and working incredible, it was too much for the 15a fuse on the Amp, rewired them non bridged and still incredible.

Now I have a new "problem", to match the performance of the subs in this new box and really enjoy them I would need to concentrate on mids and highs. I am upgrading the stock speakers but I wasn't fully prepared for this kind of bass. Just wanted a new tool/speaker box the same size as the old one :cool:
 
DSCN0185.jpg


It is an Infinity Perfect VQ with 380w rms going to it. It sounds awsome, expecially considering its a box made out of a fender, there really isn't any rattles at all. I just sealed right before the seatbelt.

I've been meaning to do this for 2 years and am definately happy w/the results party1:
We took a look at the front components today. The speaker for the front components are way bigger than what I had in. The magnet is like 4 times as big and there about 1.25" deeper. Now the problem is that, when in the speaker hole, the magnet hits the window when down. At first we were thinking that we would just put an .75" MDF ring behind the speaker but there isn't enough room between the inside door panel and the inner door skin (the stock location where the speaker mounts).

We'll figure something out though, but for now I'm exstatic and couldn't be happier with the results and can't wait to hear what the completed system is going to sound like. The mid drivers for this set are just too sweet, they look just like a mini sub :guitar: , the magnet is like 2/3 rds the size of the whole speaker.
Any suggestions?
 
Do you have any plans on how you made that? That stealthbox looks pretty sweet. Whatd you make it out of and how did you run the wires? Looks good.
 
BBeach said:
Do you have any plans on how you made that? That stealthbox looks pretty sweet. Whatd you make it out of and how did you run the wires? Looks good.


I made it out of 3/4" mdf. I fashioned it after this write-up I saw http://www.jeepforum.com/forum/showthread.php?t=97186
You can see the wires coming out of the back of the amp and going into the wheel well. All the taillight wires I just ran through the box.

grooovyone take a look at the Infinity Perfect subs they can be had for around $150 off of Ebay.
 
Last edited:
From Crutchfield, I purchased:
Sony Head unit: $250.00
Mono-Amp (400 watt): $99.00
Speaker Box (12"): $99.00
Wire package for the Amp: $35.00

From a friend, Kicker 12" Sub: $20.00

This setup is more than enough unless you want to compete in soundoff.
 
Need a little validation in my box math.
looking to do a low-pro box ximmilar to xjblue's, getting sick of the whole back taken up by my first homemade box
2048493_2_full.jpg



so, the infinity 1232w wants a 1.25 cube box (sealed)

thats 2160 cubic inches.

so just using inside dimentions, the box is going to be 21" wide per driver.

if the base is 11.75, height is 13.5, the front at a 60 degree angle, the area would be 13.5*4 added to 7.75*13.5/2

this gives a profile area of 106.31 in ^2
multiply by 21 to get 2232 cubic in.

all that math sound right? figure if i build this box i'll have room for the box and the amps underneath a rear cargo deck i can put stuff on.
 
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