Custom Sub Box

04SCTLS

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So after looking at what's available I decided to build my own custom sub box maximizing the space available under the back window.

The Legacy amp I have has rca and high voltage inputs.

Can I just hook those to the wires that go/went to the factory 6 x 9s(next to the 12" Autobahns in the pics) from the small amp.

I have the service manual on disc and looked up which ones are + and -.
However I couldn't find a wiring diagram.

I'm presuming there's a switch wire going to the small amp.
Anyone know which wire it is?

The amp is going on the side opposite the subs up to the back seats and won't be visible unless you fold the back seat forward.

There's over 3 cubic feet of space for the 2 Autobahn 12" subs and vent ports feeding into the factory 6 x 9 holes.
Should kick some serious a ss :D

2 release latches and some quick connects for the wires will make it easily movable and removable.

I should be finish carpeted and wired with this by monday so I'll take some more pictures then.

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thats pretty awesome, i hate how you cant fit a normal pre made ported box all the way back, i had two aresenal 12s and had no trunk space what so ever, then i went all the way down to 1 10 inch memphis m3 and got the smallest box i could find thinking it would go to the back but it didnt, close but not quite. its a big annoyance especially when i have to fit a bunch of alarm equipment back there as well. sorry cant answer any of your questions but good luck
 
You can use the wires to feed high signal into the amp, but you'd be better with a low-level input. Does the LS have a factory amplifier? Essentially, you'll just be taking an amplified signal and de-amplifying it some so you don't overdrive the signal and get a ton of distortion. The low-level (RCA) outputs on an aftermarket stereo is an un-amplified signal. The amplifier boosts that signal and you have less distortion this way. The factory wired outputs are amplified by the internal amp in the headunit or the external factory amp.

You can use those wires but if you have an aftermarket headunit, run the RCA's.
 
that box is simmilar to the one i made for mine. urs is much beter.

however why would yo but that sub in the LS ?

you need some fosgate or some diamond audio slappin in the back. there way more responsive sound better and willl last longer.

are you going to lay the amps on the removable trunk deck??
 
however why would yo but that sub in the LS ?
I'm sorry I don't understand your question.
yo but?

you need some fosgate or some diamond audio slappin in the back. there way more responsive sound better and willl last longer.

I had the Autobahns lying around for the last 4 years.
I was going to put them in my 97 Camaro convertable but used 8" Rockford subs into a special custom box instead.
The Legacy was only 110.00 on ebay. I have another one in my Camaro and it rocks!

are you going to lay the amps on the removable trunk deck??
There's only one amp, the orange Legacy in the pic.
It's going on the box on the in side that doesn't have the holes for the subs(last pic above) Just behind the back seat.

I'm going to get an aftermarket head unit but not till next year.
Waiting till they get better especially the voice recognition.
Till then I'll use the stock head unit as it's pretty good for a factory setup.
Finally put my posi in and want to do the turbo in the next month, so I'll be amusing myself with that.

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Theirs nothing wrong with some audiobahns, their a good low power speaker. Rockfords are bestbuy junk, one of the worst subs on the market. Diamonds on the other hand, you can make those bad boys scream.

Awesome job on the box man, turned out nice.
 
These Autobahns are pretty heavy duty with a 1000 watt (IPP) rating.
The Legacy amp puts out about 400 watts rms so it should be a good match.
The 8" Rockfords I put into the Camaro are
rated 200 watts rms each.
They were 160.00 shipped from sonix.
The Camaro box vents into the well where the top sits and works quite well
with the top down if I turn the bass volume up.
When the top is up I hardly have to turn the sub volume up at all.
 
Oh i wasn't saying the audio's are just low power, but they perform very well with minimal power applied to them. Heck I'm rocking a fusion power plant dvc, off my factory amp and it sound good. Fusion always had good response for a lower wattage sub.
 
That's an awesome box setup. I should think about making a custom box for mine.

Question, how's the ported setup? isn't the bass more muffled, and has a more spiked responsse curve (the span of frequencies for loud bass is reduced I believe).

I'm no audiophile, just that a couple audio shops discouraged the ported setup when I asked them about it.
 
That's an awesome box setup. I should think about making a custom box for mine.

Question, how's the ported setup? isn't the bass more muffled, and has a more spiked responsse curve (the span of frequencies for loud bass is reduced I believe).

I'm no audiophile, just that a couple audio shops discouraged the ported setup when I asked them about it.

I haven't fired it up yet.

It's going to vent right into the car where the factory 6 x 9s were and the trunk interior will be a further space to kick against.

I would think it would be more muffled if it was just kicking in the trunk.
 
I guess I was thinking more along the lines of bandpass. YOu know how muffled those can sound.

And vents sounds better than ported. That may have gotten me confused. Because you aren't attaching tubes to those vents right?

Again, total novice guy here, and am looking for a different way to set up my single 12.
 
I'm not attaching tubes.
I could always add them after as it would be pretty easy
for me to make them out of fiberglass using melamine as a form.
Do you think it would make any difference.
 
just keep it ported, if you gonna do tubes you shouldve just made the holes round instead of oval (sorry kinda :q:q:q:qed up right now yadig) that setup is sick id like a blueprint of that since you got the measurments out all good and :q:q:q:q so i can put some 12s in a custom box. PM me it if its coo
 
I'm moving along on it right now finishing up the carpeting.
The tilt wasn't working on my table saw so I just used a hand grinder
to do the miters.
I used MDF board and it grinds real easy.
I also cut some strips about 1 1/2" wide to make it easy to screw the MDF
pieces where they come together at an angle.
Once you get all the pieces that go around together put a piece of box board
on the big side opening and trace it from underneath with a black marker.
Cut out the boxboard and you have a pattern which should work for both sides give or take 1/4"

More later.....
 
Just an FYI.... those two holes you cut in the top of the box to go through the 6x9 holes are NOT ports... Those are simply holes in your box.

This is going to throw the tuning of your setup wayyy off... You need to calculate the airspace of the box and determine what frequency those woofers operate best in (guessing around 32ish hz). I encourage you before you finish it up to make those actually ports with port walls and all or else this is going to sound like poo.
 
Hope that legacy amp has an internal fan, but givin the fact its a legacy amp it probably doesnt.

Id worry about the amp over heating puting it between the sub box and the back seat with no air flow.

That box looks pretty sick though, i give you credit for that craftsmanship. its not adding up to me how you can build such an awesome sub box (and clearly have an understanding of car audio) and go with audiobahn and legacy. I guess if its sitting around might as well use it and you never know what it will sound like. Install is 95% of the sound quality in the end. If your setup is done right you can make even the worst subwoofers sound great on the sloppiest power out there.

But i would seriously consider comming up with a cooling solution for that amp so you dont over heat it.
 
Also as far as vented and ported go...its really the same thing. round ports vs square ports is just a matter of prefrence. Square ports are easier for the do-it-yourselfer to deal with and come up with the right measurements. round ports still confuse me!

But if you can get the right premade round port it can actually sound better then a square port due to the fact there wont be much port noise (air rushing past unaerodynamic peices). People who go with square ports try to use a router on the edges to smooth out the air flow.
 
Id worry about the amp over heating puting it between the sub box and the back seat with no air flow.

I was thinking of that and got 4 12 volt computer type mini fans about 3" tall at the flea market today for $2.00.

There's enough room for them and I can just hook them up as part of the setup.

I already had the Autobahns from 4 years ago like I said and the amp was only 110.00 shipped.
The other Legacy amp I had sitting around with with those Autobahns is identically rated 2000 watts max max( in the above Camaro trunk pic) and it works great in my Camaro.

The only difference is the 4 year old one has 2 30 amp fuses and the new one has 2 20 amp fuses.

Should be plenty of power probably total overkill

Putting the amp and subs in is the easy part and they can always be changed out.

I'm just getting ready to put the components and wiring in so I'll post some extensive documentary pics up later tonight.

I'll draw some patterns off the thing and lay out the measurements as well as my assembly advice.

You guys will love how I've secured the thing for easy removal etc....

Also since I have the interior apart I'm going to put styrofoam under the rear deck cover to minimize annoying vibrations.
 
People who go with square ports try to use a router on the edges to smooth out the air flow.

Good info.
I'll round them off with some 40 grit sandpaper before instaling the components.
 
I encou
rage you before you finish it up to make those actually ports with port walls and all or else this is going to sound like poo.
__________________

Wanna get it fired up first.
I'll make them later if I don't like the sound.
I've been doing fiberglass and pattern work for over 30 years. (I'm 50)
This stuff is like cake work for me.
 
without real ports that box isnt going to do much, your trunk will basically become the enclosure. IE you take a normal sealed box and drill some 2 inch holes in it, how is it going to sound?
 
You may have been doing craftsmenship for 30+ years, but that does not mean you know how to build a box to specs correctly. As I can see by the box, you are a very good craftsmen and obviously have patience. I am just warning that your work will not be shown if you just leave two random holes in the top of your nicely built box.

Porting into the cabin through the rear deck is a good idea.
Cutting holes in the top of the box, not so much.


If I were you, I would cap those holes off with a miniature baffle around each and then order some aeroports and drop those in after cutting to length to achieve desired tuning frequency.
 
Ok this is the maximum size box that will fit the LS with minimal loss of trunk space.

It can have vents or ports or be sealed, round or rectangular.
This is really a detail that can be easily changed or made to one's preference.

I'll put together a how to with more pics and an assembly procedure in a zip file or something as soon as I finish the wiring, putting the interior back and hooking it up to the stock system (for now).

Should be done with that by tomorrow.
Got some quick disconnects for the power wires.

For those interested pm me a request with an email address and I'll get it out in a day or so.
Minimum power tools required:
Circular caw
Jig Saw
Drill
Hand Grinder

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my bad i ment ( why would u put that sub in the ls?)

but now i understand u just had it layin around.

but yea looks good
I'm sorry I don't understand your question.
yo but?



I had the Autobahns lying around for the last 4 years.
I was going to put them in my 97 Camaro convertable but used 8" Rockford subs into a special custom box instead.
The Legacy was only 110.00 on ebay. I have another one in my Camaro and it rocks!


There's only one amp, the orange Legacy in the pic.
It's going on the box on the in side that doesn't have the holes for the subs(last pic above) Just behind the back seat.

I'm going to get an aftermarket head unit but not till next year.
Waiting till they get better especially the voice recognition.
Till then I'll use the stock head unit as it's pretty good for a factory setup.
Finally put my posi in and want to do the turbo in the next month, so I'll be amusing myself with that.
 
The holes in the top will not just make it sound like poo but will cause some serious cancellation issues.

You need to use the T/S specs of the subs to calculate the proper size enclosure and vent length for your desired tuning. with out this you are no better off then just setting the subs on the floor of your trunk.

If you need help with this check out www.caraudioclassifieds.org, there are a lot of people on there that can help you if your willing to listen. You can also PM me on here or over there (same username) if you want my help since I have a fair amount of experience designing and building boxes for the LS.
 

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