Subaru Legacy Forums

Subaru Legacy Forums (
-   Walkthroughs :: Performance Modifications (
-   -   DIY Rear Deck Vent (removing back seat and deck, and venting for better bass) (

CSTMIZR 05-29-2007 09:22 PM

DIY Rear Deck Vent (removing back seat and deck, and venting for better bass)
Hey All,

This is a short walkthrough on how to "vent" your rear deck for better bass transfer from your aftermarket subwoofer.

This will give far superior response in the upper register of the low-end frequencies and provide increased "percieved" accuracy.

You'll get better a better percieved transient as well (ie pop, think bass drum/guitar) and the bass will be truer to the music.

It's a must have in my opinion.

This one was done on hutru01's LGT (Miracle Whip) (mine is also flushmounted :cool:).

I apologize for the lack of stock shots (and maybe a few others) it was a busy project weekend and I do the best I can to record the events to share with all of you fine folks. :)

Here are a couple of links to the other recent project on hutru's MW:

DIY Additional Front Grills and Intercooler Shield:

DIY Grill Done Right (Plus Fog Bezel Matching):
(also done this weekend)

Coming within the hour..........

Here it is:

Well, here's the walkthrough and feel free to query.:)


Mock Flushmount walkthrough added in post #12.

You'll no longer need to open the "skihole" for the bass to transfer properly from the trunk. But you also have the option of having both open (Skihole = low, "rolling" bass, Deck Vent = Clean tighter bass, Both = :eek:)

It really does make a HUGE difference.........................Clean Bass, mmmmmmmmm, tasty. :)

Let me know if you need any help or clarification.

mccorry 05-29-2007 09:45 PM

I pulled the free-air plate out of my '05 deck a few years ago (it is a metal plate and gasket held in place with 3-4 bolts)... but I never cut the actual "carpeted" decking. I still get pretty good bass transfer.

hutru01 05-29-2007 09:46 PM

I can attest to the better response from my 10W6V2 sub....With the ski hole open and this vented grill, you get both the low to mid bass, and the low bass together. It definitely makes a big difference and is a must for cleaner bass in the sedans......

lakoko 05-29-2007 11:12 PM

CSTMIZR, You saved my seat squeaking problem. Thank you. Once more question. to the install the bottom seat back the ring has to stay at bottom of the seat clip is that correct?

CSTMIZR 05-29-2007 11:39 PM

^^^If I understood you correctly, then yes.

If your talking about "3." in the first (four part) pic, then the "ring" on the seat itself must go below the "bottom of seat clip" (its a hook really), then you "de-pac-man" the seat and the ring will move up into the hook. Follow by clicking in the two front rings to the notches provided.

Hope that answers your question............

lakoko 05-29-2007 11:45 PM

CSTMIZR: thanks again. I tucked the back of the seat bottom and I feel the ring is actually at the bottom of the hook.

CSTMIZR 05-29-2007 11:51 PM

You should try to get the ring in the hook if you can, but if you can't, it's OK, its not structurally critical.

Best if you get it right though, good luck..........

lakoko 05-30-2007 12:33 AM

CSTMIZR: Thanks again I got it right this time.

CSTMIZR 05-30-2007 12:37 AM

Cheers :)

CSTMIZR 05-30-2007 12:45 AM


Originally Posted by mccorry (Post 1191054)
I pulled the free-air plate out of my '05 deck a few years ago (it is a metal plate and gasket held in place with 3-4 bolts)... but I never cut the actual "carpeted" decking. I still get pretty good bass transfer.

The difference in modifing the deck itself is considerable. Only removing the plate, while marginally effective, does not provide the same result.

Of course, you will be altering a factory part and for some, that is unacceptable. For the aesthetically stringent there is the flushmount option like mine.

Note to the interested:

If you don't want to actually cut the deck, then the portion of the instructions to remove the seat and deck will still serve you well. You will experience roughly 15% of the benefit w/o deck modification. So choose your path dependent on your taste and happy modding..........

CSTMIZR 05-30-2007 09:05 PM

Here are some shots of what the flushmounted grill looks like.

If you wrap it in matching grill cloth (or actual deck carpet) it disappears into the deck, I stuck with black b/c the rest of the parts on the deck were black (and I like it that way :))


CSTMIZR 06-02-2007 02:58 PM

I thought I'd include this for anyone interested. It's a mock walkthrough on the flushmounting (wasn't doing a real one but had an inquiry).


Powerman 06-05-2007 09:55 PM

I used this walk through and it was spot on. Props to CSTMIZR!

Here are some thoughts. I didn't want a speaker grill to keep things a little inconspicuous. The flush mount was nice that CSTMIZR did. I got a grill to use, but it was from a JL sub and didn't have a mounting ring. However, a mounting ring will just be a regular mount and not flush, or subtle.

I also considered re-doing the whole deck in grill cloth. Cut the hole, then redo the whole deck so it is invisible. That is a lot of work. First the deck cloth is nice already. To add cloth it has to be thin. Then you have to get it under and fitted with all the holes and brake light and such and make sure it all fits. (why you would need to use thin cloth) Then you would have to glue that and be sure to get the vent opening very tight so it would not flutter with the bass. Lastly, if anything ever happened, or you put a hole in it, you would be looking at redoing the whole deck. So I passed.

I tried to use my grill in a flush mount, but it did not work. My grill had tapered edges and would not stay. Plan B.

I got some speaker grill cloth from an audio store. They had some pieces laying around they gave me. They also had a sheet they would have sold me if I wanted to do the whole deck.

I did just as CSTMIZR explained. I cut a small hole in the deck. I peeled back the deck cloth. It wasn't as thin and fragile as I thought. It is like 1/8 inch felt type stuff. However, you do want to peel slow and carefully. Be sure to get it all peeling off the backing so you don't tear it off. I kept peeling the cloth back and cutting my hole bigger till it got as big as my grill. I just used a utility knife. Much better faster ways, but I didn't have the tools. Then I realized my grill would not work.

So I had a 8" hole, with the cloth peeled back like mentioned. I used the spray adhesive stuff to glue the pieces around the edge of the opening. Be sure to pull tight so it will be flat. And just like CSTMIZER said, cut slits but not to the edge, or you will see it. The cloth stretches so just cut about half way.

I then decided to glue the grill cloth on the underside of the deck. I used regular spray adhesive to do this and it stuck good. I was worried it would not take to the Styrofoam backing. If you do this, be sure to get some adhesive that will stick to Styrofoam. Edit: It isn't really Styrofoam like cups, it is some sort of hard expanded foam. I will see how long the standard stuff lasts. Use a piece of grill cloth with plenty of overhang to glue to the backing. Grill cloth needs to be stretched very tight to keep it from fluttering. When I sprayed the glue, and let it setup for a few minutes, I had no problem stretching it and getting it down. I stretched it apart on one side and secured it. Then I kept pulling it tight as I went around till I was done.

This is what it looked like

Like I said, be sure to use enough overhang so when you stretch it and glue it, it has enough hold. I first cut the piece to fit then realized how little I left. That is why I glued the other piece on to help hold it. In fact, don't even worry about cutting to fit. Grill cloth stretches quite a bit. Just get it all down and then cut off what you want.

This is the finished product

And the real finished product

It isn't invisible, but it is indiscreet. Here is why I like this. Very simple. Since the cloth is glued on the underside, the majority of the bass will push against the backing, instead of pushing the cloth up if I did it on top of the whole deck. I can reach it from the underside for repairs if need be. Nothing is irreversible if I choose to do something different in the future. (Other than the big hole in my deck that is!;)) The cloth is nice and tight and there is no flutter with the sub pumpin'. I can't say how much of a difference it made because I did a bunch of Dynamating at the same time. Yes my sub performance has improved.

hutru01 06-06-2007 06:24 AM

^ That looks awesome....I have a black grill sitting in my deck, but I am perfectly ok with that. I will probably paint it the same color as my taupe interior eventually.

CSTMIZR 06-06-2007 01:21 PM

Powerman..........Absolutely AWESOME!!! Nicely Done indeed, for a first-timer or even a pro that is an excellent result!

Its nice to see someone applying the walkthroughs and especially with such amazing results. Kudos and Congrats man............ and happy listening :).

All times are GMT -6. The time now is 11:59 PM.

vBulletin Optimisation provided by vB Optimise v2.6.3 (Lite) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.