Sound deadening 2010 xD
 

Last week I had a reputable local place to install some sound dampening material in my 2010 xD.

I was disappointed by the amount of road noise in the vehicle since I bought it late last summer. Yes, there is also engine noise but the road noise is what I was trying to reduce. The audio was bad. I figured the stock speakers were cruddy and the cabin could use some sound deadening. Every review I read on the xD criticised it for 'road noise'. For good reason.

I settled on a sound deadening product called Ballistic, which is similar to the other butyl sheets with foil backing like Fat Mat, DynaMat, etc...

I liked the Ballistic material (not so much the name, but what can you do...) because the specs show it as being thicker than the DynaMat extreme which I figured would mean it should do a little better job.

Here's what they did:

• Removed seats and carpet all the way back to the spare tire
• Removed all 4 door panels
• Applied a single layer of Ballistic material on the floor -- if it was carpeted, it got covered. Including the floor behind the rear seat, including down into the spare tire well.
• Applied a single layer of Ballistic material inside of each door on the outer skin (behind the outer panel, they had to reach into the door cavity to do this)
• Applied a single layer of Ballistic material on each door right behind the door panel.
• (So each door has 2 layers of material on it)

They did not remove the firewall to put Ballistics between the engine and the cabin
They did not put Ballistic on the rear hatch
They did not put Ballistic on the roof above the headliner

Surprisingly enough, the car isn't really much quieter. For the cost, I would have to say I don't think it was worth it.

I used a sound meter before and after the install and the dB rating is about the same.

I've verified that they put it where they said they did (as much as I can) and they're a reputable place and have no reason to doubt the places I can't see.

The doors are noticeably more solid when you thump on them as compared to the back hatch which was untreated.

(They also put in new speakers when they did the sound reduction -- I went with some nice Infinity speakers, including new tweeters. They sound good.)

What I'm wondering is what else would you recommend I do to quiet down road noise?

Some options:

I could put on quieter tires, like the Goodyear ComforTred tires. But that's another $600 and it's hard to get other tires in the stock xD size thanks to an unfortunate tire size on the xD. I would have to go with 205/55R16 (I think) to be as close as possible to stock, but my speedo and odometer would read slower than actual by something like 1.5%. But it would seem if I quiet things down at the source everything would benefit.

I could see about having Ballistic put on the firewall, but that would probably mostly help with engine noise reduction and would be a hassle and costly to have the dash removed to get there. But could it be applied on the engine side instead?

I could find a place to spray onto the underbody a layer of soundproofing material, like Ziebart (though we don't have Ziebarts here). Or maybe spray the wheel wells?

I could pay the shop to put a 2nd layer of Ballistic down, not sure how much that would get me.

Any other ideas or suggestions?

I had similar results as you when i used Fat mat on my diesel dodge truck. It quieted it down some but not much - music sounded better though.

I don't have any suggestion for you but remembered when choosing between the buzz of the engine noise of the honda fit or road noise the xd. Glad I choose the xd. If you do find the solution to the road noise I would like to know as well.

My guess is the tire compound and the lack of wheel well noise dampening causing most of the road noise.

Well a second layer may help but it may not. Changing tires may help as well but sound will also travel though the windows which you can do nothing about.

Best thing to fix it and it is easy and cheap. Turn the volume knob on the radio up. :D