Sound deadening project complete...probably...

This weekend I finished up my sound deadening project, and with the possibility of putting in hood insulation, I'm done with the car. (2011) I apologize for lack of pictures in this phase as the wife had the camera and was out of town.

I had originally installed Damplifier Pro mats(Dynamat clone) from Second Skin Audio on the floor of the trunk, around the sides of that area as high as I could reach under the plastic panels, then down and under the back seat which I had pulled out. Pretty much covered all bare metal areas.

I then applied the same material to the front and rear doors, on the inside of the outside door panel. Very easy to do. Don't be afraid to peel the plastic.

The final phase of the project was to put this material, HEATSHIELD SOUND DEADENER INSULATION 4'X6' ROLL 1-SIDED eBay Item# 280553300340, on the -inside- of the plastic door panels, not on the door itself, though that may work just as well. I looked at both and decided that the tolerances might be better worked with by just putting it on the plastic, that way I wouldn't have to worry about the panel going back on easily. And if one ever needed to get inside the door for any reason, such as window motor etc., it wouldn't be in the way.

I used 3M regular strength spray adhesive purchased at O'Reillys, as the better $$ 3M heat resistant super strength grade warned of serious reactions with plastics. I had no problem with this adhesive softening/reacting with any of the plastic of the door panel. I did not spray any on that styrofoamish piece on the panel.

I basically covered every area of the door panel that I could with strips/patches of the matting. It was pretty flexible, with a thin foil backing side that I put the glue on, and crumbs of foam and other strange substances that make up the 1/4" of insulation. I pressed it onto/into the plastic of the door every where that I could. Even on the turned outer edges that are only 2" or so where it slides onto the window edge, and the very bottom.

Here's a link to someone else's install from another thread, there's one pic showing the inside of the plastic door panel. It's pretty sad how thin the plastic is, with almost everything plastic riveted and melted together. I covered all the plastic, even under the white insulation flap, leaving only speaker, door light, controls, and around some of the rivets uncovered.

https://picasaweb.google.com/octomo...?authkey=Gv1sRgCNWFkfyYjurmYA&feat=directlink

I put each panel in turn on top of a towel covered table so that it was very easy to work on. The spray adhesive does get on your fingers in a serious way, so you have to be careful not to mess up the 'good' side of the door when you're moving things around. Also tape/block areas such as the courtesy light and various connections/snaps that you don't want glue on. I also eyeballed the areas near the snaps to make sure the insulation wasn't going to prevent them from snapping in, or pushing them out once they were in.

The adhesive seemed to work pretty well, and even if a piece decides it doesn't want to stick at some point, since it's skwushed up against the metal door, it's not going to go anywhere. If I do the hood I'll buy the super dooper sticky heat resistant adhesive.

One note: Be =sure= to snap the door handle cables back into their notched holders completely when putting the panels back on the door. If you don't, the door won't open, and the cold sweats that follow when mental images of boring a hole in the door panel pop up are not a pretty sight. Lady Luck was there.....this time.

Final results, purely subjective numbers from my point of view:

D'Amplifier mats in trunk and back seat area - probably around 10 - 15% total car noise reduction, but more importantly, 50% or more reduction in general noise from the rear area, that 'hollow' boomish/echoey kind of sound that comes from hatchbacks.

D'Amplifier mats in doors - another 10 - 15% noise reduction, not a lot, but now it's evident when driving in town and on highway. Combined with trunk/backseat area there now is a discernable difference.

Door matting on inside of door - 20%+ total noise reduction. Absolutely the biggest difference of all the work that was immediately noticed. Driving around on city streets was very, very quiet now, only the low rumbling was still evident, almost all higher pitched noise (whining,whoosing/rushing sound) is absent. On the freeway not quite as obvious, but still quieter, and now I don't touch the radio volume at all.

So each step helped a little, but when added together, the total reduction made a big difference.

Lessons learned, if I had to do it again:

1) I'd only put in the D'Amplifier Pro type material on half the trunk/panel/backseat metal surfaces to stop metal vibration, and then cover the entire area completely with the sound deading material matting. This would save weight, money, and probably do just as much sound damping. The exterior door panels I'd still put 2 - 3 square feet of dampener on each. Lexus 'thump' when closing.

2) Buy the door panel remover tool before anything else.(O'Reilys) One cannot express how much easier it is to gently 'pop' the plastic rivets/snaps out instead of pulling, jerking, and cursing the panels while hoping nothing breaks.

3) Still buy the expensive mats, it was obvious they weren't going to peel off, probably ever. The trunk mats were in the car for a couple months before I put in the door mats, and when I tried to peel even a corner of one of those up, it would not turn loose -at all-.

4) Make sure to get all pics, diagrams from Priuschat, eBay manuals, etc. that show locations of all connectors, rivets, clips, etc. Really helps so that you know you're not pulling on something that needs to be pushed, etc.

My Prius is now easily as quiet as some of the other cars I drove before I bought it, Sonata/Malibu quiet or better, probably just behind Fusion quiet.

I'd do it again, and probably will on whatever next car I buy, if it's not a Lexus. Aside from back seat and a couple of spots that were very tough to pull out, generally was not difficult to do at all. Just took some time, but a weekend for a young'un would suffice.

It's obvious that Toyota manufactured the car components in a way to save money, but probably more importantly, to squeeze out one or two more mpg's for the sticker. 51 vs 50 was likely big, very big deal to the Marketing, Advertising, Executive bigwigs. So they pushed stripping weight as much as possible. They succeeded.