Sound Proofing and MLV

I have a completely stock '09 Access Cab, and I'm about to upgrade the audio system. I'll be adding 6.5" Focal 165 KRX2, a Pioneer (I think) double-din HU, a sub yet to be picked powered by a 4-channel amp yet to be picked. I know I'll be putting dynamat and ensolite on the doors and rear wall, but here's my question:

If I used RAAMmat's BXT on the floor with a 1/8" MLV on top of it, would that get rid of all road noise from the floor?

Should I mirror the roof like the floor?

What are the dimensions of the floor because I need to figure out how much to buy.

Lots here I know, but I'm trying to make sure I get it all right.

 

RAAMmat BXT is a deadener, not a sound blocker. If you cover your floor with it you'll be wasting time and money. Deadener in the doors, ceiling, and resonant panels. MLV where you want to block noise (everywhere in my case and yours too).

 

on the sound deadener showdown webpage he talks about using a closed cell foam beneath the mlv barrier. what's the difference is ccf and the raammat bxt?

 

Yes, that's how you use the MLV. It needs a substrate to help float/decouple it from the surface. You lay down the foam and then the MLV on top of it. In vertical areas it's good to glue them together as a sheet.

Raammat BXT is a constrained layer dampener as far as I know; not a noise blocker.

 

I agree with all the above, but I didn't see anyone address your MLV in the headliner area question. IMO, don't do that. I'd be suprised if it could even hold up to that much additional weight. The MLV I use is 1lb per square foot! My DC, being maybe 6' by 8', would add around 50 extra pounds if I used MLV. In my headliner I'm going with some CLD tiles (dampner) against the metal, with some CCF between that and the headliner.

 

^That's exactly what I did. No reason for MLV in the headliner really. What sound comes from above you, airplanes?

 

how thick of CCF will fit: 1/8"? 1/4"?

 

It depends for which area you'd be using it. For doors I go with 1/8" b/c it's already a pretty tight fit. 1/4" makes it a real bitch to get the panels back on. For the cab under the carpet you should be fine to go with 1/4" if you'd like. IMO, 1/8" will achieve similar results with easier install with only marginal losses in sound deadening over 1/4".

 

I'm planning to pull my rear storage bins this weekend and grind off the child restraint hooks. What would be the best product, or combination of products, to cover the back wall with before I install something else and cover it up?

 

Throw a little deadening material on the wall first and then hit it with the ccf and MLV. You don't have to do full coverage with the deadening though.

 

Thinking the 1/8" CCF should be sufficient, no? How durable is the MLV if left exposed?

 

+1

Check HERE. 25% coverage is adequate. Anything else is overkill.

 

Go with 1/8". Exposed to what? It's vinyl -- very heavy duty and dense vinyl.

 

It's funny you joke about airplanes because I live in Virginia beach which has the highest navy concentration in the world and the navy has the most planes so jet noise is ridiculous here! I use your deadening project post as a blue print but I wondered why you put the ccf and mlv just behind the panel and the tiles/dynamat on the outer most part of the door. Seems like it'd be the other way around...

 

I'm removing the plastic bins from the back wall, cutting out the child seat restraints, and hopefully having a large locking storage box built in the void. I was planning on not having a "back" built to the box and just attaching it to the back wall of the cab. So it would be exposed to items going in and out of that box.

 

Oh, I see. I get the picture now.

Other than losing small items to voids left by cracks in the MLV seams, the MLV would hold up to abrasion from items you may put into the storage bin. Unless you're constantly rubbing against the MLV with some very abrasive or sharp objects, you're fine to leave the box open on the backside. Myself, I'd put a very thin back on it just to keep small items from getting lost. If you won't have any small stuff in there, no worries then.

 

Emailed SDS to ask him about the back wall and he's going to send me a sample piece of MLV so I can beat on it a little. I'll have a better idea how the project is going to sort out once I get the plastic shells off the wall this weekend.

The only downside to putting a back wall on the box is that even a thin one is going to reduce the size a good bit just because of the contours it has to work around. I don't plan on putting anything smaller than a laptop or gun case in there anyway, but I might be able to have it built with a bottom and a short lip of a few inches on the back, which would help catch things and help protect the MLV.

 

Ahh, good point about the contours. I see what you mean.

A bottom and a short lip would probably be a good idea. I'd go with that if you can engineer it that way and still achieve the capacity you're looking for.

 

Well, if airplane noise IS a concern then here is what I'd do. Go to SDS (sounddeadenershowdown.com) and check out Don's HH-66 vinyl adhesive. You use it between the foam and the vinyl to create a permanent bond. It's not a glue, it's a contact cement so you really don't have to worry about it ever giving up. I bonded two pieces together accidentally and I had to rip the foam to get them to come apart.

When you've bonded them I'd use silicone to bond the piece to the roof. Silicone is a wondrous material. It stays very flexible, waterproof, and holds a freakin shit ton of weight per square inch. If you can find a way to hold each piece up on the ceiling for about 5 hours to let it cure it will be there forever.

As for the order of my materials that I put in the doors...there is a method to the madness. The deadening goes on any surface that is resonant. Areas that are large and flat with minimal convolutions are prime suspects. As you are probably thinking, the outside most piece of metal forming the door is the most resonant part of the entire car. That's why the deadener goes on that panel. However, you still need some on the inside skin metal of the door too. You need to seal up those holes in the door and kill any would be resonances there too. Since the speaker is mounted in this metal it's very important to try and kill vibrations at the source. The MLV is then mounted between that layer and the plastic door piece to prevent ANY noise (resonance, rattles, road noise, wind noise) from getting past that point into where the speaker is firing.

 

ok, I'm going to do my best in the next month to create a similar post to yours with pictures showing everything I've done. I've decided on a Pioneer P4200DVD head unit, Focal components, and a Focal 4 channel amp. And most importantly, I'm getting an alarm before I spend alot of money only to have my car broken into and everything stolen. Any other last bits of advice?