corradoMR2

The NX is quiet, as quiet as the 3RX I had, but in the spirit of kaizen, why not improve it even further?

Sharing with you this video that includes a comparison in sound differences as well as sequential pics that outline the steps to the work. Not nearly as detailed as previous DIYs but hopefully it's pretty clear. As per any DIY, you assume the risk and I cannot be responsible for any issues you may incur in following my video.

In scope:
~ 60% of the cabin floor.
~ 85% of the cargo sub floor.

Not shown but also done is the passenger side which is a repeat of the driver's side.

In short, tested like for like (same speed, road, day) I noticed a quieter cabin and am very happy with the result!

RDLGX

Nicely done ! I enjoyed the music on the video as well
I always enjoy all the clever things you do to the NX ! Unfortunately, I'm not smart enough to do much of it LOL

Drtbk4ever

Do you ever venture to Alberta? I'll hold your beer.

coldsoda

interesting idea with the cork foam. Ive only ever used mass loaded vinyl for barrier insulation, I have found that it seems to be the best option for its high mass and low stiffness. I've done sound deadening projects on much noisier cars, have not had the chance to do any Lexus vehicles yet. Eco cork foam is certainly less expensive, for ~$50 I can find 75sq ft of eco cork but that will only get me 22sq ft of good quality MLV.

Thanks for sharing the video!

NickTee

Mass loaded vinyl is the way to go. It is a much better insulator and that is why it is so popular for use in sound deadening projectors. The cork foam could be used as the isolation between the floor and the MLV, as opposed to closed cell foam(ccf).

webra

There is another way.

http://lexusboutique.net/?pid=1391643

On my 3IS the difference was easily noticeable.

NickTee

For that much money you could probably pay someone to line your entire car with CCF, MLV, CLD tiles, and it'd make a bigger difference than those dampers.

webra

these help handling too....they are more like clever strut bars with additional Acoustical side effects. I had them fitted to my BMW as well....they are actually made by Yamaha, tuned for different and specific applications. Made a very significant difference in the BMW. And the Audio sounds better too. Unfortunately not cheap, but for the quality and result it's fine. Recent Lexi all seem to be overweight....these add weight, but unlikely to weigh as much as full aftermarket sound proofing.

rogerh00

Is that stuff fireproof? I'm not kidding, I once had a scary fire on the interstate. That stuff looks like it would light up the interior in a flash.

corradoMR2

Thanks. It's not hard at all in the method shown. I didn't remove all the carpeting, seats, and so on. That would have been a BIG job. Lifted the carpeting and slid underneath the eco cork foam in between the top layer carpeting and existing soundproofing pad underlayment.

I'll keep this in mind!

I wanted to try something inexpensive and easily attainable. You're right on the money. Got it for $59 for 75 sq ft at Home Depot (Canada).

From tests, results, and feedback I've seen online, indeed MLV looks like it's the best option.

Note: the Eco Cork Foam is CCF as per the material specs sheet (below attached), but not sure how that impacts sound travel versus open cell foam (ccf is quieter?)

The lateral performance dampers come standard on the F Sport and loved the smooth ride over minor road imperfections on both the RX F Sport and NX F Sport.

Thanks for your concern Roger. It's safe. It meets the Federal Motor Vehicle Safety Standard (FMVSS 302). I also installed it above the existing (should be fire retardant) underlayment so nothing directly on the floor near the exhaust or other heat sources. I'm comfortable with this setup, but of course if someone follows my video and has issues, I have to throw it out there that I cannot be responsible and that the person assumes the risk. Common sense disclaimer...

NickTee

Closed cell foam typically has somewhat poor acoustic properties and its main purpose is isolation. In order to get acoustic absorbing properties, you want much thicker foams. That is the reason that you see the foam used in audio chambers is so thick. Another advantage to the CCF is it's ability to not absorb water. Open-celled foam(OCF) is semi-permeable and will allow water to go through and become trapped in some of the pores. This is not what you want in a vehicle. Also, the design of OCF does not create consistent chamber sizes of the pores in the foam, so the absorbance is not going to be equal throughout. It may over and underdampen frequencies. In this case where the general purpose is to simply lower the volume, that doesn't matter.

MLV, on the other hand, can stand to be thinner because of both the density and what it is being used for. You are using the cork foam to absorb sound, while MLV is going to be used to block sound. It will also block lower frequencies, which is advantageous to blocking out the din of tire noise.

coldsoda

^ good info NickTee. For those wanting to read a bit more from a reputable source on sound deadener materials and methods check out this site:
http://www.sounddeadenershowdown.com/

The "products" tab goes into what materials are best for each intended application. The guy is not just marketing this stuff to make money. I've met the guy who runs the site (Don) in person when I lived in Maryland and he was a nice guy that does this to help the community of audio enthusiasts more than he does to make money.

corradoMR2

Good technical info guys!

tresmith00

Pardon my ignorance but I was expecting a bigger drop in decibels than just 2.

Is a 2 decibel decrease that significant?

My0gr81

A 3db drop is half the SPL (sound pressure level) from where it started, so 2db is a good drop. Probably doesn't justify the time and effort even if costs are really low, unless you are driving a lot on country or gravel road with the sound system off. My answer to road noise is crank the radio up. Road vibration is another matter though.