Removing seat and floor liner to add floor sound deadening

[Finpro807]

I have a 2023 Integra Aspec (non-tech). I'm thinking about stripping my interior down so I can apply sound deadening material (Dynamat, Sound Skins, etc.) to the metal floor. It's just been too much road noise and NVH especially at highway speed or going through broken pavement. I was doing some research and people said the Integra didn't really have any sound insulation on the floor from the factory, and that adding floor insulation could seriously reduce road noise and NVH... Does anybody know if that's true? I went to a stero store and the guy quoted me $1600 for parts and labor (they used SoundSkin). It's a bit steep for me so I'm thinking maybe buy the material online and DIY.

Has anybody done project like this and can give me some input on your approach? Anybody knows how to remove seats (front and back), floor liner, and anything else I might've missed so I can access the metal floor frame? Is this a DIY friendly project or more of a pro only project? I'd classify myself as a handy person but nowhere near mechanic level. I'm also concerned about putting everything back correctly so I don't add more squeak and creak that Inetgra is already prone to.

Any input would be greatly appreciated, thanks! ?

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[NoelPR]

Got a better idea.
Just turn the music level up and save the money.

 

[Westhaver]

(1) Sound Deadening Project | CivicXI - 11th Gen Civic Type R (FL5), Hybrid, Si Forum, News, Owners, Discussions

 

[Finpro807]

(1) Sound Deadening Project | CivicXI - 11th Gen Civic Type R (FL5), Hybrid, Si Forum, News, Owners, Discussions

Thanks a lot! Such a great thread to read it's almost addicting. Definitely motivated me to start this project myself, just need to know how to remove the back seat first.

 

[Westhaver]

Good luck. I think the backseat is pretty straightforward, should be the same as the Civic.

 

[Integra23]

Back seat is very easy. Removing bottom portion only has a single bolt that needs to be removed, driver side above the cushion. Then 2 plastic clips under the seat that you push the seat down then squeeze clip and lift.

 

[Finpro807]

Back seat is very easy. Removing bottom portion only has a single bolt that needs to be removed, driver side above the cushion. Then 2 plastic clips under the seat that you push the seat down then squeeze clip and lift.

Thank you! Would I need to remove the backrest portion too to have full access to the floor?

 

[Integra23]

Thank you! Would I need to remove the backrest portion too to have full access to the floor?

That's has a few bolts hidden under side flaps when folded flat. Depends how serious you are but it would allow easier access.

 

[Finpro807]

Does anybody know how to remove the carpet to access the driver and passenger footwell metal frame? Preferably without having to remove the seats.

 

[Frenzal]

Don't think you can remove the carpet without removing the seats.

Had to remove the seats in my 00 Civic to remove the carpet. Might be different in the Integra though.

 

[Victorofhavoc]

@Finpro807, have you done other parts of the car yet? There's not much/any insulation in the floor (in any car really) and the sheet metal isn't quite as thin there.

From what I've read from others, the best roi comes from trunk + rear wheel wells, doors, hatch, floor, firewall. In that order.

I haven't addressed mine yet, but plan to soon with some kilmat and aggfoam. On some crappier roads, my car can get LOUD at hwy speeds. All the noise sounds like it's coming from the rear. I started pulling up some of the hatch lower trim and it's pretty clear why it's so loud the moment you tap the metal back there. It's all thin and it all echoes.

 

[Finpro807]

@Finpro807, have you done other parts of the car yet? There's not much/any insulation in the floor (in any car really) and the sheet metal isn't quite as thin there.

From what I've read from others, the best roi comes from trunk + rear wheel wells, doors, hatch, floor, firewall. In that order.

I haven't addressed mine yet, but plan to soon with some kilmat and aggfoam. On some crappier roads, my car can get LOUD at hwy speeds. All the noise sounds like it's coming from the rear. I started pulling up some of the hatch lower trim and it's pretty clear why it's so loud the moment you tap the metal back there. It's all thin and it all echoes.

That's great insights! I added butyl mats (like kilmat) on my door a while back, it did help cut down NVH and outside noise while the car was at low speed, but not much help at highway speed. The biggest difference I felt after deadening the doors was when a car passed me on the road; it felt quieter and better insulated. Music also sounded better but only at low speed.

I completely agree with you with the noise (buzzing, echo-y, drony sound) coming from the rear. I'm getting pretty frustrated with it especially if I drove through poor pavements. I've always wanted to do the trunk but hadn't thought about sound deadening the hatch. Was it hard for you when you did it?

Just got more butyl mats and aggfoam delivered today and I'll probably start on the trunk and rear wheel wells (inside cabin) this weekend. Will be posting updates!

 

[Victorofhavoc]

That's great insights! I added butyl mats (like kilmat) on my door a while back, it did help cut down NVH and outside noise while the car was at low speed, but not much help at highway speed. The biggest difference I felt after deadening the doors was when a car passed me on the road; it felt quieter and better insulated. Music also sounded better but only at low speed.

I completely agree with you with the noise (buzzing, echo-y, drony sound) coming from the rear. I'm getting pretty frustrated with it especially if I drove through poor pavements. I've always wanted to do the trunk but hadn't thought about sound deadening the hatch. Was it hard for you when you did it?

Just got more butyl mats and aggfoam delivered today and I'll probably start on the trunk and rear wheel wells (inside cabin) this weekend. Will be posting updates!

I haven't done it yet. I just got a box of foam in yesterday actually.

I've taken apart most of the hatch for another project though. It's easier than it looks, and as you remove plastic the reason it's noisy becomes more apparent.

 

[GenryHale]

I used the stuff from resonixsoundsolutions.com for my floor and doors, and it made a big difference. The install was pretty straightforward once the seats and trim were out. I left the factory liner in and just layered on top of the bare metal under it. Their products stick really well too, which helped a lot so I didn’t have to mess much with extra adhesive or anything.

 

[Victorofhavoc]

@Finpro807, have you done other parts of the car yet? There's not much/any insulation in the floor (in any car really) and the sheet metal isn't quite as thin there.

From what I've read from others, the best roi comes from trunk + rear wheel wells, doors, hatch, floor, firewall. In that order.

I haven't addressed mine yet, but plan to soon with some kilmat and aggfoam. On some crappier roads, my car can get LOUD at hwy speeds. All the noise sounds like it's coming from the rear. I started pulling up some of the hatch lower trim and it's pretty clear why it's so loud the moment you tap the metal back there. It's all thin and it all echoes.

Thanks @GenryHale for kicking this thread up and making me remember it.


Following up here, I got two boxes of aggfoam (the light stuff that comes in sheets) and kilmat butyl. I specifically targeted hollow areas and places where sheet metal has no supporting structure and would tend to vibrate or echo. This includes inside doors (behind the vapor barrier) on the outside sheet metal, behind door panels, and every crevice I could get to.

At this point I have deadened (stopped vibrations) using butyl and silenced (blocking sound) using foam in the front doors, rear doors, under rear seats, whole hatch area, and up the rear wheel wells.

On the doors I targeted the back of touchable plastics and things that echo (like upper plastic area, by the door handle, the door handle, behind the door handle, buttons, door well, speaker area, etc). Each of those areas got some butyl behind it and then was layered with aggfoam so that the foam forms a "blanket" over the whole door card. This Combo of butyl and foam dramatically improves the feel of the plastics. They no longer echo, and there's a solid thud when tapping on them... Similar to what you'd find in a German car, just not quite as nice on the feel. There's still the hard plasticy surface, but it's way more dense now. If for nothing else than feel, the butyl is absolutely worth it behind the plastics!! ESPECIALLY in really cheap feeling areas like the door "trim" by the door handles and the areas around the window controls. I cannot overstate how much of an impact selective butyl usage has!

In the hatch there was so much echo you can go hog wild. I did butyl almost everywhere and then two layers of foam on top (I will go back in and add a third layer everywhere). Huge difference doing this area. I even wrapped the whole sub enclosure in butyl and aggfoam to control the sound and clean up the sub response.

I ran without the rear doors being done for a while, then with just one door for a few weeks, and finally the last door done. There's a big difference adding the deadening in the rear doors. It cut down on the road noise quite a bit. The fronts weren't as much of an impact, but it was still a noticeable difference, especially in quality of sound coming from the speakers.

Overall, I'd 100% do this again, and I've added roughly 25lbs in sound deadening and silencing material. That's negligible really. The benefit to my children's, my spouse's, and my hearing was well worth the effort. If more type s owners were closer, I'd volunteer my time to help people navigate doing all of this.

As far as overall sound reduction, I didn't have a proper sound mic to log before and after. Phone mic and external mic to phone just do too much processing to truly be accurate in sound volume measurement. Most people have a hard time distinguishing 1 or 2 dB changes, but 3dB becomes noticeable. 6dB is a pretty massive difference that anyone can notice. For me, the sound difference was pretty drastic, especially at speed. There's still noticeable sound coming from the floor and firewall as road noise, but at the moment I'm happy. I can hold a conversation at 80mph on the hwy without having to shout at my passengers. I would estimate a 5dB drop.

On another note, the ANC system will play tones to try and drown out the road noise. I have disconnected it, and noticed a few things... In cabin noise at low speeds went slightly up, my speakers no longer rattle at high rpm while accelerating, and the subwoofer response is way tighter and cleaner. It finally has a bit of kick on the low end. I believe with the sound deadening and silencing, we don't really need the anc, and the benefits of unplugging it outweigh the effort to do it.

I hope that helps anyone else following this! If you need assistance with how/where to deaden and insulate, I'm happy to help!

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