Dynomatting doors in a crew-cab

[c5dura]

I finally decided to replace the stock stereo with something decent. In the front, I got rid of those goofy factory adaptors and drilled four holes directly into the metal to mount the fronts. In the rear they will bolt right in.

I picked up two 2-door packages of Dynomat Extreme and just wanted to check that the proper procedure is to pull out all that plastic vapor barrier material and clean off all that black glue stuff and then apply the dynomat material over the entire surface.

Will I have issues putting the door skins back on or is the dynomat thin enough that this won't present an issue?

Would I be better off getting a single large sheet for each door instead of applying two 12" x 36" strips in each door? Will these two strips cover everything I want in each door (looks like I might come up a little short in the front doors)?

Just looking for tips from anyone that has gone down this road already.

Thanks!

Btw, the components I'm going with are as follows:

Alpine CDA-9815 Head Unit (just came out)
Kenwood KAC-PS400M Sub Amp (sitting in the attic)
Pioneer 6 1/2" component speakers in the doors
2 8" Kicker Solo-Baric L7 Subs
PAC OnStar interface

[motovet]

First I will say that Dynomat is WAY to expensive. If you want to cover alot of area get some Fattmatt or E-dead ($1.30 sq. ft. with shipping)or even more economical yet,some Peel-N-Seal from the roofing supply at Home Depot (about $1 sq. ft). The Fattmatt, E-dead, etc. is identical to the Dynomat and the Pell-n-seal is the same material but only in 6" rolls. I used Fattmatt and the peel-n-seal all over my truck (see pics). As far as the big pieces verses small, that won't matter cause you will end up cutting it into smaller pieces and over lapping to work it in easier. These doors will benefit the most by coating the outer skin with a layer or two. The inner panel can't be covered completely because the way the door lock connectors route...just put deadener around the speaker area on the inner panel. The more of your truck you cover the better it will make any system sound with the added bonus of quieting the interior. Have fun!

[GMC D-Max]

c5dura~
I'd be more concerned about putting some on the backside of the outer door skin. The skin acts like a drum, and will resonate and wreak havoc with the performance of your speakers. Also, there's a supplemental pad that you position on the door skin directly behind the speaker that breaks up any "standing waves" that will affect performance. These are available at most better hi-fi shops, or here: http://www.partsexpress.com/webpage.cfm?webpage_id=3&SO=2&&DID=7&CATID=35&ObjectGroup_ID=368

Since you've already purchased the Dynamat, it's a moot point debating which is better/cheaper/easier to apply, yada yada yada. BUT, there is one more that wasn't mentioned: Brown Bread from B-Quiet. It consistently rates very high, if not better than all others. I've been watching prices on eBay for this stuff, and it's pretty reasonable. If you bought the Dynamat from a local retailer, it's a sure bet that you paid too much.

It's a mistaken notion that products like Dynamat require 100% coverage to be effective. These products are not a "sound barrier", but a vibration dampener. It requires strategic placement of patches, only as large as necessary, to eliminate resonances. It works by converting vibration into low-level heat, then dissipating this heat. There ARE other products used as barriers, but they usually incorporate some type of closed-cell foam barrier. The best sound/vibration control is a combination of both.

Ever notice that even though the cab has a massive expanse of sheetmetal in the roof, you never hear a "hollow" or resonant sound coming from it? The headliner is made from a lightweight, rigid backing (almost like fiberglass), with a layer of foam. Works quite well!

[ 04-03-2003: Message edited by: GMC D-Max ]</p>

[Silver Bullet]

Motovet,
I have had all my interior plastic trim off except the "C" pillars and the piece that runs across under the back window. What is the best way to get that piece that runs across under the back window off? Does it have the clips like the door jams or "pencil" type tips on the kick panels? Thanks.

[motovet]

Yes,like I said the doors will benefit most from covering the outer, or should I say inside of the outer panel. And if you haven't opened the Dynomat packages they could be returned as I know the stuff costs as much as 5 or 6 times the price as the above mentioned alternatives.
SB, the rear panel has the same clips as the door sills although some of them are a bit bigger. Start at one end and pull straight back and be carefull. I broke a couple off as well as one or two off some other pieces. Good idea to get a few spares at the dealership as you will probably need some down the road.

[GMC D-Max]

DUHHHhhhh thhbbpppttt....brain farting this morning! redface.gif

Yeah! What Motovet said!!
:D

[c5dura]

I picked up the Dynomat at Crutchfield (I live next to them). I'll return it this weekend as I already ordered up a roll of Brown Bread from Ebay. A 70 sq. ft. roll was $125, which is less than I paid for the two door kits and with 70 sq. ft. I'll be able to do the whole cab. I also ordered up two 7" pairs of Deflex Power Pads.

So I should cover as much of the backside of the outer door skins with Brown Bread as possible and then glue the Deflex pads on top of it behind the speakers, right?

And then cut out 4 squarish pieces to mount over each speaker opening and trim out the 6 1/2" hole for the speaker to mount? Any other "hot spots" that would benefit from being covered before the door skins go back on?

Since I'll have plenty of "bread" left over, should I rip out all the seats and do the whole floor as well? What about behind the sub box? Firewall?

Btw, I'm bidding on a pair of JL Audio 10W3v2 on Ebay instead of the Kickers.

I was going to build a box out of 3/4" MDF with the dimensions 48" wide, 11-3/4" high, 6" deep at the top, 7-1/4" deep at the bottom, but I'm not sure that the 10W3s will fit depth wise.

I also saw that Diva is running a box with these dimensions: 55 inches across, 14 inches tall 5 inches deep at top, graduating to 7 inches deep at base, but using 1/2" plywood.

Finally, skinny blinky is running a box with the following specs: 47" wide, 12-1/2" high, 8-1/5" deep at the bottom and 5-1/2" deep at the top where the inside height tapers down to 10-1/8" at the back.

It looks like skinny's box provides the most depht of the bunch?

I got a buddy with a woodshop, so he will hook me up with whatever box size I want. He wanted to use 1" MDF, but that will each too much volume, so I was thinking 3/4", but perhaps 1/2" with sufficient bracing will suffice?

This all started last weekend when I popped into Crutchfield to look at upgrading the factory door speakers, and now look at what I'm doing? Oh well, might as well do it right, eh?

At any rate, I really appreciate all the feedback, as I was clearly heading down the wrong path!

C5dura

[ 04-03-2003: Message edited by: c5dura ]</p>

[GMC D-Max]

I would imagine that you can just stick the Deflex pads right over the top of the Brown Bread.
It certainly couldn't hurt to make a gasket out of the Brown Bread for mounting the speaker, but just regular weatherstrip foam would provide a better seal if the surface is slightly irregular.
For box specs (and more info on those woofers), JL Audio has very comprehensive info on their website. Here's a link for the particular model you're bidding on:
http://www.jlaudio.com/subwoofers/10w3v2.html
Click on "data sheet" (you'll need Acrobat reader) for the owner's manual in PDF format. It has wiring suggestions and box specs. The physical shape of the box is not as critical as the volume requirement, unless the back of the box is too close to the driver itself.
Good luck!

[Silver Bullet]

c5dura,
Watch your mounting depth with the JL subs. I went with the 10W0 in part b/c it doesn't require the depth that some of the others do. My box is modeled after Skinny Blinky's...I went to www.the12volt.com to calculate exact dimensions for my box based on the space available behind my seat. I have a few pics...http://www.monkey.net/steve/truck_mod25.htm

I used 3/4" particle board...looking back on it I would use 5/8" (at least on the backside) to make the outside dimensions a little smaller (w/out changing my volume) to give me a little more room behind the seat. I mounted a couple 3/4" bumpers to push the seatback up a little to give the sub a little wiggle room...it sounds much better since I have done this. I will post my box dimensions when I get home.

From motovet's pics, it looks like he relocated his seat forward a little to get more room.

I found out it is hard to do just part...go ahead jump with both feet and do everything at once!!! :D

[motovet]

C5, Silver Bullet is right,it is hard to do just a little. In my case it has and continues to be hard to even come close to being moderate. So when I tell you I put well over 200sq. ft. of deadener in my truck, remember I did go a bit nuts with the stuff and used at least two layers on all but the roof which as GMC said is well insulated already. The results of the full coverage has made a dramatic improvement in my system however and with the added quiet it was worth all the work to me. I also sprayed the fender wells, firewall that was exposed, and much of the underside with the spray stuff. The hissing sound from driving in the rain is no longer audible. If I were to make a priority list for deadening it would probably go:1.Doors 2.Rear deck 3.Floor 4.Pillars. The firewall from the inside is pretty well tied up, so you can only cover small areas. I finished up this area from the outside with the aerosol. I would do what GMC said and put down the deadener first then glue down the reflector. My reflectors were already glued when I started my deadening and running around the pads in that spot in the door was a little tough. Also remember that there is a brace running right behind the speaker hole and you will have to glue down only the ends and middle to keep it somewhat flat. I hope you do score those 10w3's, you will like them. I am running those and went with a 43 x 13.5 x 8.5 x 6.5, to get about .81 cubes per driver minus the displacement. I also stuffed the box with about 25 oz of polyfill to gain a bit more. The dimensions you are looking at is about the max you can go with the seats where they are and will sufice for the 5.75" mounting depth the require. Your measurements will get you about .65 cubes each driver, so I would stuff the box good. My ears tell me my box is just big enough...I may even go for a bit more fill yet. Also I am running a 500 w mono to drive these and I know they could take more. Word is these drivers are more happy with about 300 ea. Late nights in the garage are in your future for sure!

[ 04-03-2003: Message edited by: motovet ]</p>

[Silver Bullet]

My box dimensions are 29 x 8 x 5 x 10.25. Again, I used 3/4" particle board. Since my sub mounted from the outside, it put the sub right up against the backseat...it was a little too close, so I added the bumpers (blocks) to the box to not allow the seat to come all the way back. This was an easy solution until I get motivated to rebuild my box. I kinda like motovet's seat relocation though...

[imported_]

I used two JLs with 3/4in mdf. We had to reccess the inside, back of the box to get the subs to fit. Make sure you don't get vented subs (down the middle of the magnet) cuz these need a min space behind them. I used grill covers to protect the subs from the seats.

[ 04-03-2003: Message edited by: Big Blue ]</p>

[motovet]

The vented subs only need .5-.75" behind them, that box C5 mentioned should cover that. The seat relocate was easy except for the spot where the middle belt mounts...had to manufacture an extension for that. The rest was a reciprocating saw and the air grinder to move them up an inch and some. Even with that I too have a couple of bumpers on the box to keep the seat up a bit. Hell move it up another inch or more I could probably get some 10W6v2's or a 10W7 or even some 12's?..... Oh yes I was told this truck must also be functional.

[c5dura]

Motovet, you sure went all the way. 200 + sq. ft.! :eek: I'll definately do the rear deck in addition to the doors, and if I end up pulling out the rear seats to get to the rear deck, well might as well do the floor as well. Late nights for sure..

I'm still a bit unclear on the exact box dimensions that will work best for me. I would prefer not to block or move the seats, and I want to use 3/4 MDF. Given the 5.75" depth of the 10W3s, and the comments I've heard here, I was thinking this might do the trick:

...../\
..../..\
.../....|
../.....|
./____|

7.5" deep at bottom
5.25" deep at the top
10.25" high at the rear before angled top
11..25 high at the front top edge

The top front corner is supposed to be 90 degrees (this is basically blinky's design with slightly modified dimensions for better seat clearance).

C5dura

[ 04-04-2003: Message edited by: c5dura ]

[ 04-04-2003: Message edited by: c5dura ]</p>

[Silver Bullet]

C5,
Just a thought...if you go with 5/8" instead of 3/4" you can get save 1/8" of external depth while still maintaining your box volume...but this will also depend on your box design. With as tight as these things fit behind the seat, 1/8" of an inch goes a long way!!!! :D

[motovet]

C5, did you try some cardboard to get a profile of your proposed dimensions to determine if the fit is right? If you end up with the 10w3v2's you should try to get as much box as possible for the best sound. The sound deadener was very addictive for me. My wife was getting worried....about the truck.

[Silver Bullet]

Motovet,
I like the way you think!!! I had 3-5 cardboard wedges laying around!!! I didn't take enough into account for how much the sub stuck out from the box which is why my fit is pretty tight.

[motovet]

SB, that sounds awfull familiar. I also had quite a few cut outs before my final dimensions. Also did this before I had the speakers in hand and ended up with the bumpers. Before the bumpers one of the woofers touched at the top edge.

[c5dura]

Ok, figured I'd give you guys an update:

I scored the 10W3v2's for less than 3 bills delivered. Should be here tomorrow. :D

The cardboard check fit box is a good idea, as I want to get real close to max without touching the seats. I think around 7.5" at the bottom will squeak me by with almost 1" behind the 10W3v2 magnet, and will give me .675 ft3 per side using 5/8 mdf and a middle divider to create two sealed enclosures. JL recommend .625 ft3, so this gives me a little extra.

I came across JL Audio XR650-CSi 2-way component speakers at a very good deal, so I picked up 2 sets for the doors. After reading a lot of negative stuff about "rear fill" speakers on the car audio forums, I might not install the tweeters in the rear doors, but then again I might and just turn their gain down (the XR650's have adjustable x-overs).

Still need to install all the sound damping material which I'm sure will take QUITE a bit of time, which bring me to my question;

Motovet, should I remove the vapor barrier completely to install the Brown Bread, or just pull back sections at a time? Not sure what will be easier since I haven't pulled any of it back yet, but I know that black glue stuff is real messy.

Time to go look for an amp to drive the components in the door since the head unit's 27Wx4 RMS isn't gonna cut it, or is it? The XRs have a sensitivity of 89.5 dB. Guy I know used to be in SQ type competitions, and told me to forget about the internal amp given the other elements of the overall system. He might have a point. Hmm, the JL 300/4 would complement the other JL pieces nicely I bet. Boy, that tax refund sure is going fast. :eek:

Btw, I REALLY like the Alpine 9815. Super fast MP3 play back and very clean playing CDs. Built in 6-channel electronic x-overs, 5 band parametric eq, 6-channel time delay, and a nice 2-line display scrolling folder and file names at the same time.

C5dura