Customized my factory 6.5" sub box to support an 8" Subwoofer (w/ pics)

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samsonite
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Customized my factory 6.5" sub box to support an 8" Subwoofer (w/ pics)

Post by samsonite » Thu Jan 14, 2016 6:54 pm

My car came with a 6.5" speaker box. I'm modifying it to support a 8" subwoofer.

I'm going to use Bondo-Glass 272 Fiberglass Reinforced Filler to fill in the holes.

The subwoofer that i'm using is an Infinity Reference 860w - which is a fairly deep 8" sub (5-3/16"). After mocking it up, i have plenty of clearance. I'll post more pics as I progress. I don't have too much left to do. The factory side panel that covers the box, im going to cut the hole larger. The subwoofer will stick out just a bit from the panel but not much.


Stuff:
(2) 3/4" thick 8" subwoofer rings - MDF
---i glued them together and to the enclosure with Loctite PL375


1 Piece of Lath wood - used to build up the back side of the enclosure.


1 Piece of fiberglass weave. Glued this over the lath strips. Going to put BondoGlass over it.


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Last edited by samsonite on Thu Jan 28, 2016 5:38 am, edited 2 times in total.

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Derf
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Re: Customizing my factory sub box to support 8" Subwoofer (moon and tunes)

Post by Derf » Fri Jan 15, 2016 3:31 pm

Looks good thought about the same when I had the rear cargo area apart. The 6.5" OEM woofer is ok, but 8" would definitely be a better match. Are you going to add anything in or around the plastic box to minimize resonance? The odd shape of the OEM box seemed to create peaks in the bass characteristics. Awaiting the final install pics.
2005 #10,524 Neptune Vibe "Bandit" Auto, Moon & Tunes 220k :D
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samsonite
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Re: Customizing my factory sub box to support 8" Subwoofer (moon and tunes)

Post by samsonite » Sat Jan 16, 2016 6:26 am

Derf wrote:Looks good thought about the same when I had the rear cargo area apart. The 6.5" OEM woofer is ok, but 8" would definitely be a better match. Are you going to add anything in or around the plastic box to minimize resonance? The odd shape of the OEM box seemed to create peaks in the bass characteristics. Awaiting the final install pics.
I thought about fiber glassing the outside of the box. I'll have to see how it sounds first. The nice thing is they really made the plastic structural by adding webbing inside of the box. So i'm hoping that it is strong enough as-is. We'll see.... I have a 12" Alpine sub in my car right now that i've unhooked and i'm dieing from the lack of bass. Really hoping this box and Infinity 8" work out. I can use all the free space i can get.

Oh also on the odd shape, i guess one good thing is there wont be any standing waves! :lol:




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samsonite
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Re: Customizing my factory sub box to support 8" Subwoofer (moon and tunes)

Post by samsonite » Sun Jan 17, 2016 8:07 pm

Getting closer. I ended up using wood and fiberglass on the backside. It's nice and strong. I didn't trim the fiberglass mat in case I end up glassing in the whole box, which i still might do but I'd like to test everything out first. I'm really missing not having a sub. It's like i'm missing 1/3 of the music.

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Re: Customizing my factory sub box to support 8" Subwoofer (moon and tunes)

Post by SlammedNiss » Mon Jan 18, 2016 2:50 pm

Considering I carry a wheelchair around with me everywhere I go, a basic woofer box is out of the question. If I could ever come across one of these panels + enclosure, this is exactly something I'd be interested in doing.
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samsonite
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Re: Customizing my factory sub box to support 8" Subwoofer (moon and tunes)

Post by samsonite » Tue Jan 19, 2016 7:16 pm

Powered up the sub tonight. WOW! I'm not normally impressed with car audio speakers, but this Infinity Reference 860w sub is really accurate and has just enough bass with 400 watts running through it to shake things and rattle the license plate. I wasn't sure how the plastic box would hold up to the bass but I saw no indications that it's not structurally strong enough to handle the bass. It sounds very good also!! I have my amp cutoff turned to 80hz and everything down low sounds nice and smooth.

Anyways i'm really happy with the results. I can't recommend this project enough to anyone wanting to hear all the lows subs offer, and wanting to save space. The 6.5" box is perfect for most 8" subs - i'm just estimating here, but it looks like it's close to .35cu ft. I could be wrong but it's closer to what 8's need vs. the newer box they put into the '09-'10 Vibes.


Tips on converting the box:
-You will want to use a high strength adhesive on the ring(s) AND screw them in from the backside of the box using wood or sheet metal screws and washers. The sub is heavy and you don't want it to become a missile in a car crash. So fasten it as strong as you can!

-You don't need to cut out the backside if you choose a lower profile sub. The Infinity is one of the deepest 8" subs, but also one of the most highly rated, so that's why I chose it.

-Once you mount the ring on the box, you will have to seal 3 holes around the side. I used Bondo Glass but there might be better stuff (i.e, fiberglass, or maybe some kind of epoxy). Bondo Glass is known for cracking - only time will tell if it holds up. It's easy to chip off and re-do if that happens.


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vibrologist
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Re: Customizing my factory sub box to support 8" Subwoofer (moon and tunes)

Post by vibrologist » Tue Jan 19, 2016 8:59 pm

samsonite wrote:
Derf wrote:Looks good thought about the same when I had the rear cargo area apart. The 6.5" OEM woofer is ok, but 8" would definitely be a better match. Are you going to add anything in or around the plastic box to minimize resonance? The odd shape of the OEM box seemed to create peaks in the bass characteristics. Awaiting the final install pics.
I thought about fiber glassing the outside of the box. I'll have to see how it sounds first. The nice thing is they really made the plastic structural by adding webbing inside of the box. So i'm hoping that it is strong enough as-is. We'll see.... I have a 12" Alpine sub in my car right now that i've unhooked and i'm dieing from the lack of bass. Really hoping this box and Infinity 8" work out. I can use all the free space i can get.

Oh also on the odd shape, i guess one good thing is there wont be any standing waves! :lol:




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I put a layer of batting into the original box after seeing derf's mods. I really think it helped. But I don't know for sure because I also sound proofed the whole trunk area.
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"It is important to know the difference between 'accurate' and 'precise' even if you are neither!"

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samsonite
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Re: Customizing my factory sub box to support 8" Subwoofer (moon and tunes)

Post by samsonite » Wed Jan 20, 2016 5:54 am

vibrologist wrote: I put a layer of batting into the original box after seeing derf's mods. I really think it helped. But I don't know for sure because I also sound proofed the whole trunk area.

Nice. Yeah, i guess i'd recommend this if you're looking to expand what you hear. The 6.5's, even aftermarket ones, wont hit the low notes like kick drums, bass guitars, rap, ext.. really well. Doing an 8" sub will really add volume and feel to the music. One thing I noticed is that sound really fills the cabin and you hear less road noise with bass. I noticed I drive with the radio slightly lower in volume having a subwoofer. Each time i've done upgrades, the tweeters, 6.5's, the volume knob goes down a tad. Just nice to not have to crank music to hear it clearly. I don't think I can ever go back to not having a sub but im kind of an audiophile even if I don't have the highest end stuff.



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Re: Customized my factory sub box to support an 8" Subwoofer (w/ pics)

Post by vibrologist » Wed Jan 20, 2016 8:27 am

I like what you are saying, Samsonite. After my soundproofing job and batting in the box mod I flat lined the equalizer because I had enough bass. My system is all stock and 10 years old.
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samsonite
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Re: Customized my factory sub box to support an 8" Subwoofer (w/ pics)

Post by samsonite » Wed Jan 27, 2016 6:49 pm

Well after a week of using the sub box i went back to take care of some resonance problems at certain frequencies. I could have read a 100 different ideas on deadening the box, but I decided to give molding clay a try. A tech from Parts-Express recommend it. So I went to Home Depot and picked up 2lbs of duct seal compound and went to work. I got about 2/5th's of the box done so i'll need to pick up more. Man, this box is getting heavy. :lol:

http://www.homedepot.com/p/Gardner-Bend ... C4C2984BE8

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Oh and I also deadened all the doors and rear quarters. 8-)

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Re: Customized my factory 6.5" sub box to support an 8" Subwoofer (w/ pics)

Post by ImUrOBGYN » Thu Jan 28, 2016 8:32 am

WIsh I had an eclosure. I have a GT with moonroof, but no enclosure. Moon and NoTune package? Either way, I have an 8in bass tube I'm gonna have to hook up.
I spent a lot of money on booze, birds and fast cars. The rest I just squandered. - George Best
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Re: Customized my factory 6.5" sub box to support an 8" Subwoofer (w/ pics)

Post by samsonite » Sun Jan 31, 2016 6:49 pm

The duct seal compound worked a little too well, quieting the box down too much. So i pulled half of it out until i got the sub tuned to where i thought it sounded best. Looking back, i should have just put the duct seal behind the subwoofer on the inside of the box and some of the areas of the outside of the box. That way i wouldn't have lost any volume. Oh well. It's almost done now. Just need to find a grill and dress it up a bit on the sides so it doesn't look so ghetto.

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Last edited by samsonite on Sat Feb 06, 2016 4:48 pm, edited 2 times in total.

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Re: Customized my factory 6.5" sub box to support an 8" Subwoofer (w/ pics)

Post by SlammedNiss » Sun Jan 31, 2016 7:35 pm

Will be interesting to see how you finish the rest of the installation. Can't wait to see pics of the finished project.
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Re: Customized my factory 6.5" sub box to support an 8" Subwoofer (w/ pics)

Post by hotbug1776 » Tue Feb 02, 2016 5:34 am

Given what you have done here, do you think an Infinity kappa perfect 12d vq, with a mounting depth pf 7", would fit into the subwoofer panel like you have mounted your 8"?
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Re: Customized my factory 6.5" sub box to support an 8" Subwoofer (w/ pics)

Post by samsonite » Tue Feb 02, 2016 7:32 pm

hotbug1776 wrote:Given what you have done here, do you think an Infinity kappa perfect 12d vq, with a mounting depth pf 7", would fit into the subwoofer panel like you have mounted your 8"?
I think I'm only about an inch from hitting the spare tire cover when I open it. i want to say no but I'll check tomorrow and give you guys a max depth size you can go.

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Re: Customized my factory 6.5" sub box to support an 8" Subwoofer (w/ pics)

Post by samsonite » Wed Feb 03, 2016 6:00 pm

hotbug1776 wrote:Given what you have done here, do you think an Infinity kappa perfect 12d vq, with a mounting depth pf 7", would fit into the subwoofer panel like you have mounted your 8"?
So I measured tonight and I have 3/4" of an inch of clearance from the spare tire lid. Considering the Infinity Reference 860w mounting depth is 5-3/16 i'd say you'd have to get creative if you wanted to go beyond 6 inches mounting depth. The easiest way would be to clearance an inch off the lid but that might be kinda janky. Or you could relocate the electrical box thingy behind the sheet metal wall behind the box and cutting a square hole through that to give you more depth to work with. It's possible is what i'm saying but will require more work.


EDIT: I just realized you were wondering about a 12" subwoofer. I wouldn't recommend going beyond 8".... I mean maybe if you used an 8" ring then a 10" ring then a 12" ring to build it out (this would be weird and i don't know if it would even work). There just isn't room for mounting beyond an 8" ring on the box.

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Re: Customized my factory 6.5" sub box to support an 8" Subwoofer (w/ pics)

Post by ImUrOBGYN » Thu Feb 04, 2016 9:00 am

If you want to do something larger, I don't think you should use the same spot at the OP, either. If you're opposed to using a regular ol woofer box, you may consider custom building a box that'll fit in the spare wheel well/hatch storage area.

Samsonite, due to your sub size, are you unable to keep the speaker face flush with the interior paneling?
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samsonite
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Re: Customized my factory 6.5" sub box to support an 8" Subwoofer (w/ pics)

Post by samsonite » Sat Feb 06, 2016 4:51 pm

ImUrOBGYN wrote:Samsonite, due to your sub size, are you unable to keep the speaker face flush with the interior paneling?

Yeah, there isn't enough depth for this sub to make it flush.


I think i'm done with this project. I could make it more eye pleasing but i don't have to look at it everyday.
It would annoy me if I looked it everyday, but as they say... out of sight, out of mind. :lol:

Anyways it sounds great. I couldn't be happier with the amount of work/reward of this project!!

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Re: Customized my factory 6.5" sub box to support an 8" Subwoofer (w/ pics)

Post by hotbug1776 » Mon Feb 08, 2016 5:25 am

Thanks for the help and info. Depth is really the only restriction for that sub, as it can fit into as small as a .4ft3 box. What I may eventually do is make a box that attaches to the spare tire cover or back of the passenger rear seat. This would allow me to fold the seat down still when I need extra space, or my spare.
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Re: Customized my factory 6.5" sub box to support an 8" Subwoofer (w/ pics)

Post by murphb00 » Thu Apr 21, 2016 5:52 pm

Hi samsonite. Do you still have pics of this mod? Looks like they've been deleted on here. And pardon me if I missed it but are you still using the factory stereo? I'm wanting to replace my head unit but I know it all goes through the factory amp so I would have to go with line level leads and all that crap and don't really want to. I have a 2009 GT with the monsoon system. Any help would be greatly appreciated. Thanks.

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