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Trunk execution, how to cram stuff and make it look OK?
Posted: Sun Jun 21, 2009 10:25 pm
by PhyrraM
While test fitting my Praxis components in the trunk it dawned on me that I have more than just that stuff to fit in there. I have a whole stereo system to fit also.
While I know stereos are a bit 'ol skool and not as popular as they used to be, I have a lot of good stuff hanging around and I do spend at least 90 minutes in the car commuting everyday. Plus I have a completely different SS that I can dedicate to "performance". This one is dedicated to "daily driven street fun". A kick ass stereo certainly needs to part of that equation.
I haven't looked at or researched "systems" and "installs" in about 10 years. What I need are ideas, links, pictures, etc. Throw it at me and I'll try to digest it. I guess I need to find some stereo forums and stat browsing.
Because my posts are nothing without a few pics

, here's what I need to deal with.
One idea:
Another possibility:
Air tank:
No spare?:
Add a few amps. Not all are needed, but not yet sure which ones will be part of the system.
In addition, I need to find space for these also:
Any, and all, input appreciated. I know we have a few installers on the board that can get me kick-started in an old hobby.
Posted: Sun Jun 21, 2009 10:35 pm
by __TT__
wow havent seen that year soundstream amps in 5+ years.
nice stuff really timeless. If it were me i would start by putting the subs in the spare well with a fiberglass box, then throw the amps on the right side tire well and the praxis system and capacitor on the left tire well. then throw the tank whereevers cleaver
Posted: Mon Jun 22, 2009 12:02 am
by Legacy777
I'd just be cautious about getting rid of the spare.
Posted: Mon Jun 22, 2009 1:27 am
by magicmike
I'd mount the huge air tank to the underside of the rear deck, make a box for the subs that has them firing straight down that fits under the tank and mount the amps to the front side of the box so you can see them with the seats folded down. Leave the red valve thingy in the left corner where you have it pictured. The sony ES pre amp or what ever that is can go under the driver seat or in the right side of the trunk. Put the changer under your passenger seat. Make the sub box so there is 2 inches of clearance on the bottom for the air its going to be moving and for enough room to lift the spare tire floor mat cover in and out so you can still have your spare.
Have I mentioned I used to be an installer?
your welcome

Posted: Mon Jun 22, 2009 1:39 am
by PhyrraM
__TT__ wrote:wow havent seen that year soundstream amps in 5+ years.
nice stuff really timeless.
I bought all that stuff about 10 years ago for my Mazda MX-3. I took it all out in 2001 when I bought my WRX. It's been on a shelf ever since. Those Rubicons are the last series of "true" made in the USA Soundstream amps and subs. Not pictured is the famous CDX-C90 w/the optical output. I only need to buy a front soundstage. Not sure what I'm going to choose.
magicmike wrote:I'd mount the huge air tank to the underside of the rear deck, ................
........... so you can still have your spare.
Have I mentioned I used to be an installer?
your welcome

I think your on to something........
Thanks!
Thinking to make it a fiberglass enclosure moulded to the underside of the rear deck to save as much usable space as possible.
I just found out I need to get those Exact 10s repaired. My brother had them for a while and upon a test firing I hear rattling. One is a cone cap, but the other might be the voicecoil. This really bums me, those things sounded sooooooo cleeeeeaaaaaaan when new.
Posted: Tue Jun 23, 2009 2:27 am
by PhyrraM
Ok after thinking about what MM said I went out to the car to size things up.
I made a rough template of the area under the deck.
I layed out the major components on the template.
A little photo-chopping, as much to scale as possible. Blue is car structure/sheetmetal. Red is my proposed box/amprack.
I think we are getting somewhere.
What are my options as far as caonstruction? MDF would weight a ton. Are there any "new" techniques I'm not aware of? Is fiberglass really any lighter by the time its properly strengthened and dampened?
Posted: Tue Jun 23, 2009 2:38 am
by kimokalihi
First off I would ditch that cap. Caps are over rated and they're mostly just marketing BS.
Caps are for bassheads who compete in SPL comps. You really won't need one.
Usually people use them for headlight dimming. But basically it's just another thing your alternator has to charge. Another tax on the system. If you're having dimming problems you need to address the problem(s) that's causing the dimming. A cap is just a band aid and will only wear out your alternator quicker.
Check the "big 3". The power and ground wires from your alternator to your battery. Make sure they are of sufficient gauge. It is recommended to upgrade them to 4gauge at least. Depending on the amount of power your amps are drawing and how many amps your alternator is putting out.
This alone completely got rid of my dimming problems in my toyota pickup. Upgraded all the power and ground wires with 4 gauge amp wire. Shrink tubed with nice connectors and wire loom to protect them. I was amazed after the dimming went away, the wiring was pretty bad and of about 10gauge wire.
When I had my first legacy it had pretty good size wires that weren't corroded or exposed and there was no dimming and I was running a 4 channel infinity amp putting out about 200 watts to my sub and 150 watts rms to each 2 way 6.5" midbass and 1" tweeter running passive crossovers. No dimming.
Anyways, if you upgrade your wiring to nice clean new heavy gauge wire and you still have dimming problems it's probably your battery. I ran an optima red top in my subaru and it's going back in my new subaru when that's running. I run an oddyssey deep cycle in my metro with a 55amp alternator and 4gauge grounds and power wires and was running a huge elemental designs nine.5 5 channel amp running about 500 watts and no dimming.
So, I would scrap the cap. It's all marketing. It's a scam. I hate caps.
Posted: Tue Jun 23, 2009 2:40 am
by kimokalihi
Fiberglass is lighter. I gotta go to work. I'll show you what I'm working on now when I get off.
Posted: Tue Jun 23, 2009 3:05 am
by PhyrraM
The cap is a leftover also. I don't know if I'll have problems in the Legacy or not. I didn't really need it in the Mazda, but they were popular and I had cash (I was still single). But your right, I can't say I heard a difference. All the old good amps had a ton of capacitance built in anyways.
My thumping days are over, but I can still appreciate a good sub workout on something nice and tight. Old Beasty Boys, Run DMC, etc. This build is going more SQ, but I don't plan on adding 100 pounds of dampening to the car or cramming 8" drivers in the door.
I really wish I was capable of just "thowing something in" and calling it a day. But, alas, I've got some diesease that forces me to research absolutely everything and "do it right". Or at least as "right" as possible within a given set of comprimises. In all honesty, I can wait much longer to get the stereo installed, but I can't see doing a bunch of trunk work on the Praxis and NOT do the stereo at the same time. It's the Praxis I'm having a hard time waiting on.

Posted: Tue Jun 23, 2009 5:42 am
by 93forestpearl
If you build a FRP box the right way, it will be really strong and much much lighter than a straight layup of multiple layers. The key here is using core construction techniques. In the composites class I took a while back, adding 1/8" of a basic foam core increased the stiffness by 400%. The more you separate the inside and outside layers, the more rigid your piece becomes.
Eventually I want to make a carbon box since the material has come down so much. Or, for half the price you can get black fiberglass that looks exactly like carbon. I plan to make thin shell as a basic frame, with a MDF ring to screw the sub to. The walls will be foam with cloth layup on the inside and outside. You can even get an inexpensive device that uses your air compressor to pull vacuum.
Its a lot of work though....
Posted: Tue Jun 23, 2009 7:22 am
by __TT__
PhyrraM
I'm going to save you alot of work, ditch that design, your subs will never get the head room they need and itll sound like they are being underpowered
ps I've installed since i was 16...I'm 33 now. 14 years of that was professional.
Posted: Tue Jun 23, 2009 7:25 am
by __TT__
also if you use the spare well you will save ALOT of weight because roughly 80% will be fiderglass.
Besides, whats the point of using a spare nowdays with AAA and not even to mention I wont use a spare due to the possibility of screwing with the AWD.
Posted: Tue Jun 23, 2009 9:27 am
by asc_up
In reference to fiberglassing, I know a few people who designed whatever it was that they were making out of balsa wood. It was cheap, light and easy to shape. Then they fiberglassed over that and everything is strong and works great!
Posted: Tue Jun 23, 2009 4:15 pm
by magicmike
Personally I'm not going to get into a circle jerk here on trying to convince you of which idea is best for you. All I will say is that I've built fiberglass enclosures, HDF encosures, and even alot out of birtch. In all of my experiences I always recall being dissapointed at how a fiberglass box sounded for all of the work it took to build it. There is something about birch that makes a sub box sound amazing. No needd to stuff or dampen the box either. for a 10" I always do .8 square feet for each driver sealed. This has always worked best for me. The bass is tight and accurate with that volume.
Posted: Tue Jun 23, 2009 10:01 pm
by kimokalihi
.8 sounds about right. Depends on the sub though. I have a pair of Image Dynamics IDQ 10" subs that call for only .5 sealed box.
Posted: Tue Jun 23, 2009 10:40 pm
by PhyrraM
No worries about bashing egos. I asked for ideas and I accept them all. I'm smart enough to eventually filter out any BS.
TT and MM, I appreciate both your input. I did a fiberglass spare tire well with a MDF top in the Mazda all that stuff came out of. I was single and kid-less, but never once had a problem without the spare. Now I've got twins that I tote around OFTEN. I'm having a hard time justifying the lack of a spare. I did like the way it sounded. It was SOLID and heavy old school Home Depot fiberglass. It was about 1 cubic foot per sub with a ton of fiberfill to smooth it out. I have heard many good things about Birch also.
I saw pics of an install that used "corner pocket" subs. Have either of you done that? How did it work out?
Got any favorite stereo BBSs? I've been reading a bit on DIYMobileAudio. Man, those guys are SQ freaks. While I appreciate thier pursuit, I'm not prepared to go through the lengths some of them are.
Now for a wild idea....Fabricate an airtank that fits in the front fenderwell, opposite the air compressor?
Posted: Tue Jun 23, 2009 11:08 pm
by kimokalihi
I used to spend tons of hours over on DIYMA but I don't like it there anymore. It used to be the coolest forum I've ever been on and it was privately owned and run with no moderators and the members of the board basically took care of problems (if there were any) on their own.
Then Npdang sold the forum to SecondSkin owner Ant and it quickly went to hell. He wasted no time changing everything he could about the forum. Changed the look of the forum, added about twice as many categories as before, most of which are unnecessary.
But somehow all of this things he's done with the forum have attracted all the users from caraudio.com and the elemental designs forum ICIX and a lot of jerks and people who only care about bass and blasting music out their windows at stoplights are there now.
It used to be a strictly SQ forum. No SPL. SPL people had plenty of other forums already and there weren't really any SQ forums except EliteCarAudio or ECA but that place was on it's last leg which is probably why everyone went to DIYMA.
I used to browse the car audio section of the forum every day but now it's just full of stupid crap. Now I don't even bother looking in there.
There's still a handful of cool people on there that know a lot about car audio though.
If you thought they were all about SQ now, you should have seen it before lol. The old DIYMA crowd would have been outraged at the idea of an SPL section on that forum but ANT put one there. And when I spoke up about it and about how he's totally taken the whole idea of the forum and the reason it was there in the first place and turned it inside out, I got flamed by all the new members. That's pretty much when I stopped going there for the most part. Once in a while I check out the off topic section when I'm really bored and there's nothing new on here.
Posted: Wed Jun 24, 2009 2:27 am
by magicmike
PhyrraM wrote:Now for a wild idea....Fabricate an airtank that fits in the front fenderwell, opposite the air compressor?
how much pressure and how many gallons are we talking about here? I was thinking you could buy 2 small but longer tanks and mount them under the rear deck. That would give you alot more room to work with. I think you want to keep the tank central to all 4 corners though. or at a minumum when you cut the air lines measure the front runs and match for the rear and leave the tube coiled so the air passes the same "distance" that way the car should raise and lower pretty evenly.
Posted: Wed Jun 24, 2009 3:25 am
by PhyrraM
I'll do some research. I think I can safely reduce the volume of air. It's mostly to provide storage so the compressor doesn't run all the time.
The way the system works I don't think the length of the lines will make much difference. There is nothing about keeping lengths close in the insall manual. But I will find out.
Good idea on the twin tanks. That is very doable if needed.
No comments on the side mounted subs idea? Here is the link I dug up.
http://www.gadrivers.net/~dwicker/fiberglass.html
I do have the skills to do something like this (slowly), but do you think it's worth the effort? I'm waffling on the trade-offs in usable space between losing the back of the trunk or losing the sides of it.
I need to get a '06-'07 WRX spare so I can gain my utility tray back.
Posted: Wed Jun 24, 2009 3:37 am
by PhyrraM
To keep my motivation and inspiration high, I found a few minutes to clean up the amps and diagnose the rattling sub.
The sub has the foam surround seperating from the basket along with the "padding" that is normally covered and compressed with a grill. I temp mounted it with the basket out to compress everything back down and it sounds just fine.
Any ideas on what type of glue I can do a permanent repair with?
Pics.......because I love pics.

Posted: Wed Jun 24, 2009 3:45 am
by 93forestpearl
Any idea on the pressure the system runs at? Building tanks from scratch is a serious endeavor. Companies that build them go through all kinds of certifications. Our 235 gallon unit at work has to get certified every year as a pressure vessel even though it only handles 100 psi.
You guys may chastise me here, but I prefer the sound of a vented box. Not too loose, not too tight. One Type R twelve in a properly done vented box (at 1.5 ft^2) was money for me. I grew up on bandpass though, lol.
Posted: Wed Jun 24, 2009 4:08 am
by PhyrraM
Yeah we have one at work also that gets certified. The compressor is rated at 150psi. I am trying to find out what pressure the tank maintains. I'm *guessing* based on a quick measurement of the bags and the approximate weight on each corner, that the system runs about 60 PSI. I'm sure the tank runs higher however.
I feel confinent I can build a safe tank from sheet metal, but it will only be worth it when I run out of other options.
I've always liked the tightness of a smaller sealed box in the past, but I'm still open to anything that produces acceptable quality and a small box (or boxes). Hell, I haven't decided whether to run 1 or both subs yet.
Posted: Wed Jun 24, 2009 4:10 am
by 93forestpearl
Meh, one should be enough to hear the bass if you aren't looking to rattle your doors. I got over having two subs a long time ago. My one twelve in a vented box was more than perfect.
Posted: Wed Jun 24, 2009 9:46 am
by kimokalihi
It's all preference. I don't like the sound of ported boxes. They're sloppier and boomier. I like nice clean tight bass that blends well with your stage (the speakers up front) so you can't localize where the sub actually is. That's money right there. I actually don't even like the way subs sound in the trunk. Cuts out the detail in the bass and leaves you with a lot of bump and not much else.
I'm actually thinking about doing an IB setup in the rear deck behind the seats with a couple 10" subs. I dunno though, that's a lot of work. You have to make sure the trunk is sealed off from the cabin so sound waves from the front of the sub don't cancel out when they hit the sound waves from the back of the sub. But the cool part is that you don't use any trunk space because they're just openly suspended from the rear deck and no box is necessary. I've never done one before because this is the first sedan I've owned but I'd like to give it a try.
Posted: Wed Jun 24, 2009 2:57 pm
by magicmike