Space saving sub idea...

xB_Jag_Bx · 10-23-2009, 01:14 PM

I've been looking at getting 3 MB Quart RLP304 sub; which according to Performance Auto & Sound (pasmag.com), that it only needs 3 inches of mounting depth, which is also what MB Quart advertises. Pretty shallow for a 12" sub, and it is a DVC sub to boot. Then I got to thinking: "how cool would it be to build a box into the hatch?" My thoughts very. I measured the area and it appears that I could cut out that boring peice of black plastic and the surrounding sheet metal to insert the box which would hold the structural intregrity of the hatch. I also feel I could easily build the box as each sub only requires .5 cubic feet of air in the enclosure, and there would not be much more than 1 1/2 inches of lip on the box (Maximum, if any).

So I wanna know what everyone thinks of the Idea.
Would you do it yourself?
And where do I get a roof mount amp rack (if they are still availible)?

Jeremiah · 10-23-2009, 01:22 PM

sounds cool but you better sound deaden the HELL out of the hatch man. just thinking about all that rattling is making my head hurt lol.

xB_Jag_Bx · 10-23-2009, 01:30 PM

Yeah deadening there would be overkilled

**ogerdgonz** · 10-23-2009, 01:33 PM

Bad idea, the hatch is not solid enough to mount 3 12" subs for proper acoustics. It will hold them no problem but the vibrations from the lightweight hatch will probably cause a phase shift in your sub soundwave. Also the hatch shocks would eventually fail due to holding the extra weight up.

xB_Jag_Bx · 10-23-2009, 03:05 PM

Quote:

Originally Posted by ogerdgonz

Bad idea, the hatch is not solid enough to mount 3 12" subs for proper acoustics. It will hold them no problem but the vibrations from the lightweight hatch will probably cause a phase shift in your sub soundwave. Also the hatch shocks would eventually fail due to holding the extra weight up.

Do you think that going with 1 or 2 subs would cause the same phase shift issues?

Who needs a hatch anyway? I suppose I could weld it shut, or split it so only the glass part opens.

Black_Box · 10-23-2009, 03:19 PM

few a F/G pr C/F hatch...then C/F into it.

meant F/G into it!!

xB_Jag_Bx · 10-23-2009, 04:14 PM

I am not up to date on the lingo, Black Box, what do you mean? C/F is Carbon Fiber, but what is F/G? OOOOHHH Fiber Glass... So you think it will work if the box is Fiberglass or the Hatch if F/G?

Black_Box · 10-23-2009, 04:16 PM

i dont see why not.....alot of boxs are built of F/G so if you had a F/G or C/F hatch, and you just built the sub boxs into the hatch..you may have better luck then in a stock metal hatch

xB_Jag_Bx · 10-23-2009, 04:23 PM

I didn't think about building a F/G box, I was thinking MDF, but that may ad to much weight, to go along with what ogerdgonz was saying, I may have to ask around at Home Depot or Lowes for something lighter but the same strength as MDF, and if I made the box out of F/G I would still need to reinforce the box in some sort of way.

If I went with one sub there, I could get a nice small 150 to 300w mono to rock it, and also custom mount the amp in the hatch as well.

I know slightly off topic but this is post #30!!!

Black_Box · 10-23-2009, 04:26 PM

for f/g tips and such..where i went

Fiberglass Forums - Powered by vBulletin

lots of good info and stuff there!!

**ogerdgonz** · 10-23-2009, 04:47 PM

with how small those subs are just do two under the front seats and then mount the amps in the hatch.

joey17 · 10-23-2009, 09:22 PM

remember you always need to build a box to spec or it will sound like poop. and i would just do under seat still really clean and alot less work cuz finber glass and bondo is a pita lol i had to do my whole box bondo cuz im painting it and wow it sucks or you could get one loud shalow mount and then mount the amp under the other seat it will be super clean.

859Toaster · 10-26-2009, 12:33 AM

This is my old sub set up. I ran a single 12" sub, and amp in a spec matching box. It faced up... And only lost maybe 3"s of height storage. Big deal right? lol

As you can see, STEALTH AS A MOFO! What I did was build the box, and install it. Then cut a piece of 3/4" MDF board and secured it to the C pillar Walls.

Here are a few of the during install pics:

I eventually leveled everything out, and junk, but just don't see a pic of it in my account. (oh well)

I built this set up for Scion Exposed 2008. I am not a sub person. Left it in for a few months, and took it out and sold it. It sounded great. Hit harder than a lot of people and their pre fab best buy specials.

I can't remember the specs on my box, but it wasn't massive as you can see. With the cover over it, I could put whatever I wanted back there with no worries to it hitting the sub. Only problem is, no more spare tire.

gravebox · 10-26-2009, 04:56 AM

Quote:

Originally Posted by xB_Jag_Bx

Do you think that going with 1 or 2 subs would cause the same phase shift issues?

Who needs a hatch anyway? I suppose I could weld it shut, or split it so only the glass part opens.

welding it shut would only stop the failure, or at least the worry of failed shocks. using any SET of woofers in a non-solid area will cause extra vibrations causing the woofer cones to go out of sync, AKA phase shift from one another's operation. this will greatly effect the over all sound quality and output.

in all honesty, the hatch metal is not strong enough nor solid enough even with bracing to deal with that kind of load. it's simply there as a door to the outside, nothing else. i would HIGHLY suggest doing your enclosures into your quater panels or make an open deck / heavily grilled enclosure on the cargo flooring.

JP_Extreme · 10-26-2009, 07:07 AM

Quote:

Originally Posted by 859Toaster

This looks a lot like the one I got going on now.

Anyways I would suggest doing this or going under the seats. Just an FYI amps shouldn't be mounted upside down since the heat can cause harm to the circuitry in the amp. So I would only suggest doing it if you don't plan on using it everyday then I would say go ahead and try the hatch design just make sure you don't forget to deaden the heck out of it and fill it with foam. That will help reduce the vibrations through the hatch. And definitely fiberglass an enclosure the MDF will be waaaayyyy to heavy for the hatch to stay open but you will still need to use if for structure support just keep it to a minimum.

xB_Jag_Bx · 10-26-2009, 10:34 AM

No offense Grave, as you make some very good points, but the masses say go for it, so I will unless I think of a better idea when I have the funds to add some bump to my box.

My first goal is do something differently, as no-one has done this install, and there may be reason for this, but I plan on using light weight matrials to begin with; that and, using more sound deadening materials and methods than most would, I feel that this is a possible solution. The fact that these subs have a smaller mounting diameter, 10.6 in, and only require .5 cubic foot airspace only furthers the possiblity of this solution being viable.

My wife's uncle has connections that uses Fiberglass primarily in thier fabrications, and would be able to get me a reduced price and/or use of thier facilities to build my new box. I have also reduced the number of subs to 2, as the 3rd would be 2 much money as my modding budget would be less than I would like, but I am sure that it will increase over time, and the stereo is the first upgrade that I want to do.

Sure, I could move spare to be mounted under the car, but as I don't have the funds to drop my xB on bags and if I lower the car in the future I would then have to find another solution to keep the spare tire, as I doubt my wife would understand the, "that is why we have road side assistance." line.

To deal with gas struts not be strong enough to hold the hatch, I am sure that I can find stronger ones to replace the stock struts to compensate for the added weight.

If I come of as dick that is not my intention, as I appericate your input as I do everyone who has replied to my orginal post, and is the reason I joined in the first place.

This solution is not set in stone either, as I am waiting for the OK to buy stuff for my car. All I know, right now, I don't want to drop in a prefab sub box in my xB, but I would if that is what my budget calls for, as a last ditch effort.

Thank you again for all the feedback, both pos and neg.

gravebox · 10-26-2009, 04:03 PM

regardless of your choice, we're still here to help. just know that my areas of expertise is in the audio world and career wise i work heavily with metal.

it DOES sound like a good idea, but fully knowing the strengths of the hatch door and understanding the characteristics of the audio world tells me otherwise.

also know that the hatch isn't completely sealed off from the outside. if you take a flashlight and look deep to the edges inside the hatch cavity, you'll notice small water ways that have been leaving black-ish road residue. before you do anything, you'll need to make some sort of colvurting to those areas. ONE you don't want to block those drain points because you'll trape water inside the hatch and cause pre-mature rusting and TWO you don't want to leave wide open and allow condensation on wires and other equipment after the install. so take some flexible tubing, cut about 1/4 of the side off all the way down and then use it as a kind of pipe around those drain points and seal the edges with sylicone.