charchri4

This page gets a ton of air play on the net about mounting subs in the back deck but I can't find anyone that says much about how it works. Seems to me all it would do is rattle the tin in the shelf and from and enclosure point of view it would be hard to come up with a worse cavity to call a tuned sub box.

Anyone getting decent sub sound with this? Or anything else for that matter!

tbone heller

I put 2 subs in the back deck of Mr. Miyagi. I did basically what the guy in your link did, But I insulated mine to make it a sealed enclosure. Of course I don't have any pictures. After cutting the holes in the deck, I placed two 1 gallon-size paint cans (wrapped in tin foil) in the areas that the sub's magnet would be located. I blocked off access to the trunk from both sides of the fuel tank. Ran a couple lengths of pvc pipe in front of the tank from one can to the other (for increased air volume). Then I filled the area with Great Stuff Foam. Be sure to cover everything that you don't want ruined by the foam. After the foam expanded & dried, I carved away the excess with a carving knife, pulled out the 2 paint cans (the foam stuck to the foil allowing the can to be set free), & opened up the area for the pvc pipes. I had to make some "rings" out of some 3/4" wood to raise the subs so their cages would clear some of the structure. All & all it does not rattle or sound bad.

Gator Bait

Not done yet, but my intent is to do something similar to the web page, but instead of cutting my parcel deck I'll make a baffle board (MDF) top and front to replace the current sheet metal. I'll form the interior of the enclosure with fiberglass. This project will be as soon as I get the car back from it's nose job. I'll be sure to take pics and document for the forum.

charchri4

^^ That is exactly what I was thinking about doing too. If you pull that package shelf out of there you gain a ton of volume in front of the fuel tank and I was thinking about just making a new package shelf out of 1/2 mdf to use that space.

What's holding me back is I already have full range speakers mounted in the tin pretty much like Tbone did his by blocking off the passage to the trunk at the roll bar and making a little cab out of the space. With no way to put speakers in the seats that is pretty much the only place to put rear speakers so I'm sort of stuck between a rock and a hard place.

I may do a little down firing cab for the center or pull the whole mess out and somehow incorporate the full range speakers on the sides with a sub in the center of the same panel / box. Just don't know what the best approach is.

PS for me a foot well sub is out of the question because I spend plenty of miles in the passenger seat!

Braineack

my 10" trunk sub worked VERY well. thing was only like .5 cuft but I used a sub designed for small spaces:

Tang Band WT-1427G 10" Neo Subwoofer

Gator Bait

I was considering that as the passages on either side of the fuel tank into the trunk ought to allow sound to travel. For me it came down to that I wanted the tighter bass and mid range support a pair of 8s could provide over the boom of a 10 or 12.

Braineack

it hardly boomed. it was very tight.

coupled with my amped components that set up actually sounded very decent. can overpower top-down highway driving wind noise.


and an idea of how loud the car is without MJ

Meierznutz

I was offered a Boss Frog sub as a beta tester. The 500watt amp kicked the 10" woofer very well. The enclosure fit over the jack cubby and I used 2 sheetmetal screws through the drip rail of the trunk (RTV for sealant) into the box to secure it. I am sure you could make the same box from MDF. The sound was great but wasn't annoying in the BOOM BOOM BOOM buzz the license plate off your car kind of way.

charchri4

I think I have a plan here. Right now I have the same 6.5 rounds in the deck as I do in the doors but the doors sound 10 times better. I think the reason for that is the doors act as a resonator but in the back there is no space for them to perform like they are in a speaker cabinet.

I like Gators idea of making a top for the deck out of MDF. That will increase the size of the cavity a little and have something solid the speakers can work with. I've got a small 2 channel amp so I'll change out the 6.5s with higher power 6x9s in the back deck and hopefully that will overcome the lack of cabinet back there.

For a sub I'm going to build a small down firing cabinet to hold a single 8" and put in on the deck. It won't kick my chest but with it right behind me shooting against the MDF on the deck it should fill in the sound spectrum plenty good. It will also be easy to pop out for autocross and what not.
The goal is to have it done by the 19th for the annual Christmas romp in the snow.

Gator Bait

You might try a couple of mdf baffle rings or a even just a square mdf board for the 6.5's to sit in. You'd be surprised at the difference they can make by stiffening the mounting surface. The problem/difference could be as simple as the doors being stiffer than the deck. A weak mounting surface will cause the coil energy to be absorbed changing the sound quality and reducing output.

charchri4

Really. Humm now that's very interesting. It's exactly what I was thinking by covering the deck but if I could get away with a smaller piece and no amp that would be so much the better. I think I'll try not covering the entire deck then and just go out a few inches from the speaker to secure it to the deck and see what happens.

I have to change out the deck speakers anyway because some moron did some grinding too close to them and got metal filings all down in side them. You like the idea of bumping up to 6x9s while I am at it? is what is in the deck and doors now and is what I want to change to.

Gator Bait

You could do the baffles below the deck also (sandwich the deck metal between the speaker and mdf). But you want a good flat solid mounting surface.

Examples of baffles:

charchri4

That's pretty much what I pictured. I need to put it on top to space it up some to fit the bigger speakers. But these speakers only have a 3" mounting depth I could just build a little box for them.

charchri4

A couple nights in the shop and voilà a small down firing cab!






















Next up the 6x9s but not till I get heat where the car is or the car to heat!

charchri4

Back at it today. I decided it would be wise not to bury the panel to access the fuel pump so I trimmed my speaker mounts so the panel could come out with out taking the speakers out.


I had to do a little beating to get the 6x9s in, especially on the passenger side. I probably pushed it down far enough to hit the tank but I just used a tap hammer to not push the tank in at all. Hopefully I did not pinch any fuel lines either!


They are not symmetrical because 1, I don't care, 2, no need to beat on the drivers side if they are not and 3, no way am I moving the fire extinguisher again! (This is the 3rd mount)




I can't decide if I should put the carpet back on the deck under the sub or not...


It really doesn't show much from the back. Not that I would care if it did... it's all about the bass!


I painted it all with left over car paint before I came in hope to power them up tomorrow!

charchri4

Gator Bait

If you aren't putting your carpet back on the deck, you could use some spray glue to attach some WalMart black carpet to the fuel tank access. That would conceal it and help with any rattles from the sub.

charchri4

Turns out cutting around the fuel tank access was a mistake. 3 screws and the drivers side speaker pops right out so it was needless. I may remake that one but I do want to put something down back there for the top to sit on when it's down. Before I had a layer of sound stuff and the carpet. I'm going to road test it to Omaha next week if the weather plays nice and we'll see how it goes.

Gator Bait

maybe make a second baffle board for below the deck off the top template to sandwich the metal with. It'll make it even stiffer and give the screws something to grab on.

523-LSX-NB

Nice work. Bet that thing rocks.

charchri4

I tried to do a video but doesn't come close to the feel or presence of the thing.

Gator Bait

music choice approved. Brings me back to Nawlins.

Meierznutz

Damn-it.... no "Like" button

charchri4

Oh yeah love them blues! That's Lisa Mann and she is one of my favs. Check it out she plays 6 string bass.

Gator you have a real treasure just down the road in Austin you should check out. She's a lot like Rory Black but with a fresh take.

Gator Bait

Wife grew up in Austin so we get out there a few times a year, but it's hard to keep me up late enough to see a live show. Come 9:30p I expect to be seeing the backsides of eyelids. As bars move away from allowing smoke I might be inclined to give it a go again, but I just can't tolerate the atmosphere these days so I go looking for outdoor, daytime music festivals. Jazz fest is a my favorite but I have never been to south by southwest in Austin yet.