Kaban

I know dynamats are used mainly to bounce off sound from speakers instead of absorbing it. But is it effective to use them for sound deadening as well?

Right now, I am going to put dynamat original on my driver and passenger side floor. Not to make stereo louder but to deaden road noise coming from mainly tires. Will it make any difference if I turn the mat face down to help bounce off the sound from the road?

What about Dynaliner/Max? I couldn't find any at my local Best Buy but saw the flier that comes with Dynamat I bought.

disc108

i think dynamatting is used as a sound insulator.. it keeps the music in and roadnoise out. so you should just put it "facing in" (normal) and it should be fine.

Kaban

thanks Disc,

I am going to get the mat today and put it in and see how the results are.

Mean Gene

Kaban - Dynamat's for sound deadening, not wave reflection. Percy's mentioned a material called Deflex which works in the manner that U describe, I think. Dynamat designed to reduce resonance more so than soundproofing but it works well for that additionally. Original's good but Premium's better ( same deadening but half as thick ). Plus there's Dynamat light for use on trunk lids or anywhere that it must be overhead ( like a roofline ). Let us know the results from your project!

Kaban

Well, I finally finished up dynamatting my car floor.
First I must say the Lex is build with extremely attention detail. Every wire is bundled up with electrical tape and secured in place by clips.

After I flip the carpet up, I noticed the steel panel already has plenty of sound isolation materials. But obviously not enough that's why I am dynamtting it. From the firewell down to the fuse box, a soft rubber padding is bolt down with the bottom part of the dash. Removing it will requires major work, so I left it alone.
From the break paddle area down to the seats is padded by a hard plastic board glued with some type of industrial strength adheisvie so removing the plastic will be impossible as well.

So the mat will go ontop of the rubber padding and will be stick on the plastic material on the the floor.

I then measured and cut the mat so it fits from firewell down to the seats. I cut a 3x3' hole on the upper right corner mat so it fits around the round plastic gas paddle stop. On the passenger side is easy fit, a 4 sq. ft. mat will fit perfectly with no cutting.
All this took me about 3 hours to do it including a lunch break.

After I am done, I took the GS out for a test drive. I dynamatted the door panel a few weeks earlier. The results are AMAZING. From the door panel down, I couldn't hear any noise at all. All the sound is now coming from the windows. Tire and ground noise is barely audiable now.

The only noise is still hear is from tires when I go over rough surface and concrete roads on the free way. After I get my 18' rims with SP9000 tires, this noise should be reduced quite a bit. I still have stock 16' rims and tires.

I know I probably left out a lot of details, but typing this is harder than installing the mat. But this is definitely worth the work going into it.

disc108

how long did it take u to do all this? how many sheets of dynamat did u need and how much did it all cost? is the car dead quiet?

also, i don thtink getting 18" rims will reduce your roadnoise. if you increase the contact area with ur bigger rims, your roadnoise will increase. unless your tires are super, super quiet.

Kaban

It took me around 3 hours to do the floor. Door panels took a day because I spent a while to get the panels off.
I got a 13 sq ft. mat and a 4 sq ft mat. I ran out of mat and the 4 sq ft mat fits right into the passenger floor with no cutting, cost $70.

The car is basicaly silent untill on the free way when the tires start to make noise, but it is still a lot quiter than without mat. I am hoping the Dunlop SP 9000s would be quiter since it's a high quality tire instead of cheap oem tires. But I won't know untill I try it out.

Hardest part I think would be getting the mat to stick on the floor. The floor board already has sound deadners glued on it, so making the mat stick evenly will take some extra work. But it is definitely worth the time doing it tho, the car is a lot quiter now and my stock amp magically increased about 50 watts power.

Mean Gene

Kaban - Nice way of wording that about having a "suddenly more powerful amp". Though the Lexus IS well insulated from the factory, the Dynamat ( or in my case, Stinger Roadkill matting ) almost doubles the deadening from road noise! Too many people forget that by reducing this surrounding noise, they increase the sound levels that they actually hear. Dynamic range seems to improve & U hear things that before U may have missed! Keeps the wife happy, too when she can't hear the Borlas as much anymore!! At least ya didn't need to cut some channels in the mat to allow the passage of your power wires & RCA's - d*** 0 awg is thick!!:eek:

RadarB8

If you want a super quite ultra high performance tire try the Yokahama AVSdb. Tire Rack reviews for performance are extremely good and they are as quite as a tire gets hence the db designation.

Kaban

Thanks Radar, I'll call up Tirerack and ask them about the AVS.