BradRX330

I've an 04 330 (built in Japan not Ontario if that has any bearing) not as quiet as I'd like it to be at highway speeds anyone have experience with sound proofing these units or know of how to's? thanks in advance.

gtsnake

The RX line usually comes with factory sound proofing. If you want to add more you can always get some sound proofing mats. However, you will need to remove all the inner panels to install and they will add a lot of weight.

joedaddy1

iTrader: (1)

tires.. get quiet tires.

BradRX330

Yeah I went with Walmart cheapos

tomr51

tires are the biggest difference in noise. Cheap tires are normally the noisiest. I have fitted cooper CS5 to my RX350 and find them to be very quiet.

ToledoRX

It could be that or it could be a bad seal. I have not had any issues with noise at highway speeds. Lexus soundproof their cars like a Cocoon - so it probably tires or dried out seal.

MikeB139

Coming from an '99 E38 bmw 730D, I find the RX far from quiet.
I've done extensive sound proofing in the rear that made little difference. I still need to do three doors and half of the rear wheel wells (inside of course).
2mm Silent Coat and on top Dodo Pro Barrier MLV, taped with 3M aluminium tape to seal the air gaps.

To find the places where the most roadnoise is coming from I had a friend drive at highway speeds and I used a decibel meter.
That showed that indeed the wheel wells and rear/front doors are the main culprits.

I was simply baffled by the totall lack of sound proofing.
Taking out the panelling revealed a total non existence of sound proofing.... Just a very small piece of fabric here and there.
Nowhere near the sound proofing in the BMW. It is basically on the same level as my wives 1/5 of the price Renault.

On the doors I replaced all the damp shielding (plasic) and replaced it with sound deadening panels which I also taped with industrial strength aluminium tape (made for -50c to +150c).
Make sure you cover EVERY opening as moisture will find a way!
In the doors I placed some strips of the same sound deadening to quiet down the "ringing" from the outside panels. When you tap it now, it sounds like a thud, i.o. "boing"

Anyway, here are some pics.

Oh and I have new quiet tires on mine (Vredestein Sportrac 5).

tomr51

on your db meter, what were the difference in sound levels?

BradRX330

That is very helpful thanks much for the reply, is removing the the rear wheel interior pieces difficult?

professorm

Wow, you did a lot of work soundproofing. That is pretty extensive.

MikeB139

Measuring at head and door level there was a 3-4dB difference, which is significant.
Most of the noise comes from road noise in the lower frequencies, which are hard to suppress.

That is why I choose to replace the plastic sheets in the door by ("heavy") sound deadening.
There is a definate difference between the driver door (which I treated) and the passenger door.
It's quite an extensive job, which takes about 2 hours per door.

I was busy anyway, because I also replaced the foam surrounds from the speakers.

MikeB139

The ones in the trunk not so much, but removing the parts between the rear seats and door requires removing of the rear seats (which I will be doing the coming weeks).

tomr51

thks for the update mike

BradRX330

excellent work Mike,would you happen to have a materials list as to sound deadeners a such ?

MikeB139

Silent Coat 2mm mat: Silent Coat
Dodo Pro Barrier MLV: Dodo Pro
3M Aluminium tape: 3M tape

All of these can also be found on Amazon and Ebay.

The Dodo Pro Barrier is a pain around corners though. Had I known this, I would have opted for something different.
Since I bought a lot in advance (I hate to keep re-ordering stuff) I will use it to finish it.