Sound Proofing

[Azmodon]

The '10 grand tin can' as we all know, earns its name when it comes to road noise and every other type of noise that could exist in a car - anyone who's stripped the trunk of carpet and plastic knows you can see outside from inside where you really aught not to lol

So while I figure out the mounting of the diffuser, I'm also getting started on phase 3 of sound proofing the car.

Phase one - strip the interior and line the floor with (not) dynamat (used "noico"), pictures to follow.
cost: ~$75

Phase two - bridging the gaps in the trunk (wheel well to fender... damn thing's a drum skin) with "reflectix" - a thermal barrier for duct work that just so happens to be a great sound absorber (unpoppable high grade bubble wrap lined on both sides with foil)
cost: ~$30

Phase three - I'm going to fabricate some VB-3 from Cascade Audio. Normally the stuff is $9.80ish per square foot... I'll be laminating aluminum foil in place of the lead sheet they use since it's density changes, not density itself, that causes these materials to function. The foam I'll be using is Volara since it's rated for a 54 decibel drop at 1/2" thick. Since I can get 250 square feet of foam for $70 (+shipping... which'll be another 50ish because it's so heavy). Halved since it's the bread of the sandwich puts it at 125 sq-ft.
250ish square feet of heavy duty aluminum foil is ~$6, assuming I use 10 layers to reach somewhere near 1/64th thick, that's ~25sq-ft per roll, 5 rolls to do 125 = $30... + spray adhesive... so like, $160ish, to get 125 square feet of VB-3... $1.28 per square foot, instead of $9.80/sq-ft + shipping.

Won't make all 125 though, should be more than enough to load the doors without doing that and then line the inner skins with just the foam.

So that's what I'll use this thread for - progression pics of the VB-3 assembly will come, for now, here's some of the ones I took while installing the butyl rubber sheets.

rear cover removal



Pulling the headliner not all the way off

Mind the air bags


after feeding in a sheet, smoothed over scrapper acts as the 'roller'

[Azmodon]

Rear door - plastic pulled up (all pop latches)


How to remove these dudes




4 bolts per seat, out they come

another for the seat belt


the pile


Pulling at the edges, everything just comes up

[Azmodon]

peeling the carpet back - Didn't remove the centre console... really should've lol





Mind the stem

[Azmodon]

fin


so yeah... now to glue layers of foil together as I wait for foam to arrive :P

[brady]

fin


so yeah... now to glue layers of foil together as I wait for foam to arrive :P

sorry to bring up a post from so long ago, but how is the difference, did you find it worth it?

[Azmodon]

I did, with the race exhaust it was quite loud inside. I've since built a silencer to insert in the muffler, and it's really nice now but still keeps the growl. If I took the time to do it again, I would also put more effort in to fully covering the roof.

[brady]

I want to do as much as i possibly can on mine, how much did you use, the stuff im ordering comes in square meters and i dont want to get too little but i dont want to have enough for a second micra when done either haha, i plan to do the whole floor, hood, firewall, roof, hatch, doors, up the pillers front mid and back as much as possible, plan to make this tin car sound like a mercedes, going to do a full sound system probably next year as well. i was going to install a/c but havent been able to aquire the parts needed, so sound deadening i shall do.

[UAMUWT]

Gutsy effort trying to make a K13 quiet!
I recently bought a 2011 Australian spec 1.5 manual Micra and its certainly got its good points but NOISE is probably its worst!
I've analysed why its noisy compared to all the other small hatches I've owned going back many years.
It bothers me that my K13 has a rear mounted exhaust. All my other lil cars had front mounted exhausts.
I can see small threaded posts welded to the engine bay side of the firewall/bulkhead and scuttle so Nissan allowed for the fitment of soundproofing pads but never fitted any, BAD MOVE!
Its interesting that my other car here, a 2017 Suzuki Swift auto is quiet but then it has a front mounted exhaust, soundproofing pads on firewall/bulkhead and scuttle and the underside of the bonnet/hood plus it has VERY thick bonded carpets with thick fabric underlay attached.
Most of my past cars had little or no sound proofing and thin carpets but not all were noisy.
My K13 has VERY low gear ratios compared to my other cars. I have to short shift to avoid using high revs and the resulting ROAR. Silly choice of gear ratios!
Some cars simply have components that are either quiet or noisy and harmonics and vibrations that buzz around the body are expensive to eliminate. Car makers don't as a rule bother making small economy cars refined.
Trying to retro fit soundproofing to the engine bay side of the firewall/bulkhead looks to be impossible with the engine in place
Its just too crowded in there and the scuttle on the K13 is not removable as it was on my K12.

[UAMUWT]

I decided to try adding soundproofing to my 2011 K13 but already its fighting me pretty good.
Except for the dash the interior is mostly stripped out.
My headliner is not just mechanically fastened at the edges like my K12 was. Its been glued over much of the central area so it won't come out, bummer
Carpets were fitted before the dash so the only way to get them out without cutting them is to remove the dash. NOT an appealing idea
Some good news though.
The firewall/bulkhead on mine has a chopped cloth pad on the inside face and the carpets are thick with bonded chopped cloth underlay (decent quality) so its scary to think how rowdy the K13 would be without this fairly good cabin soundproofing!
At this point I will try to add a layer of foil backed butyl rubber to the inside floor and I will try to add underfloor soundproofing to the exterior/underside. Adding extra rubbery stonechip coating to the wheelwells might help. I plan to stick some kind of sound deadening mat to the underside of the bonnet/hood though not sure what type yet.

[MrMicra2015]

yikeberries! you disassembled your brand new car!