TSXTim

After some noise problems the K&N CAI install,
I put dynamat inside the inner fender and was amazed.

With door speaker replacement I installed sheets of
dynamat to the outer door skin. amazed again.

I'm on a mission to exploit this stuff but it is expensive.

I took door panels off again and put strips on the inner door panel and more on the outer door skin. For example the plastic surround the encircles the speakers and anywhere else I can make good use of it.

When changing truck lights, with the liner off the truck lid,
there are spots to install pieces to the outer skin and the
inner structure.

Basically I tap around and anywhere there is a hollow metal
sound can be improved.

There is a crossmember across the rear of the trunk
that is absolutely hollow sounding. A few strips of this
stuff works wonders.

It doesn't have to be used in full coverage sheets, it's
too expensive and not necessary.

The car is getting so much better, the rear bass is loader
and tighter. The car doesn't need a sub for those of us
who don't want to go around making boom boom noise.
I have lots of bass now.

Next a full surface of dynamat on the rear speaker deckis my weekend activity.

Also, Circuit City has a much less expensive brand that
gives more square foot for less money in a speaker kit.
The $35 rolls of dynamat come out all
wrinkled which I don't like. It's best to work with flat sheets.

There is liquid paint-on material that would be great for hidden
places like under the front hood insulation and rear trunk areas
that are covering with liners.

I need to try some of the paint on stuff. I'm on a mission.

CDR

Good stuff! I'm working on sound reduction for a 99 Prelude, but might eventually do some on the TSX. Some additional questions and comments:

• Where/how did you install on the inner fender? On the inside of the engine compartment?
• Any other continuing hints on which spots helped the most is useful ... I'd expect your "hollow sound" criteria is a good one.
• Another possibility for improvement: Sound absorption foam barriers (see www.b-quiet.com and others). Dynamat and coatings reduce vibration (noise conduction) and resonances through the metal of the car. Acoustic foam and noise barriers are a complementary approach, I'll be putting this into the firewall and floor area of the Prelude in addition to the deadening. Requires removal of the carpet (and everything inside the car), but I was going to do that anyway on the Prelude.
• eBay seems to be the least expensive place to buy Dynamat Xtreme, several vendors selling the 36 sq. foot "Bulk Pack" for around $100 + 20 shipping or so (heavy). Much better than the $250 list price for the same item.
• I bought a gallon of "QuietCoat" liquid sound deadener -- is this what you're referring to? (www.quietsolution.com). The claim, and their test reports, are that beats dynamat. So far, I've only tried it on a dishwasher tub (as an experiment). Seems to work, although you need to put 3 coats on to over 1/10 inch (3 mm) thick, which looks pretty messy. Spraying on would look better but is hard to do in a small space.

tuan209

there are just as good alternatives out there like RAMMAT and second skin that are much cheaper. If you join CAF you will automatically get 40% off.

TSXTim

For the CAI I just did inside the inner fender because the
bracket will transmit right to the inner fender.
A rubber washer between the bracket and fender also helped
there. When I
go back in there I'll put some on the outer fender.

The quiet coat needs several layers and dries
with a rough surface, I heard. So it would take time to build up
coats and is a dissadvantage. I wouldn't spray around the car.

fdl

I imagine this stuff adds wight. How heavy is it? It sound slike you may have added 20 lbs to your car

TSXTim

Suprisingly light. One guy said the full trunk kit,
which is maybe 4 times what I have used so far, was
8 lb.

waTSX

When you talk about noise reduction, do you mean the Dynamat reduces road noise, or just that it improves the sound of the stereo by improving acoustics?

That would be sweet if it cut road noise, because sometimes the TSX gets a little noisy over rough road.

Thanks.

TSXTim

Sound is complex physics. Basically any sound external
or internal will vibrate everything in the structure.
These sound waves can combine constructively ( loud noise )
or destructively ( noise cancelling noise ). Every permutation
of noise randomizaiton occurs and you have the full spectrum
of sound frequencies occuring in noise chaos.
The dynamat material dampens this in the car's metal.

Obviously we can't get to all of the car's metal, so we can
only improve some.

At the audio store they have a dime size piece of dynamat
on a bell. Take the piece on and off to hear the effect.
With dynamat, it is a thunk with no continuing vibration.

This will reduce vibrations in the structure from external noise
and from the sound system. Less external noise and less
constructive interference will occur and the sound system sounds better.

Road noise is tire elements slapping the road surface, and the waves and pulses of air coming out of the tread grooves.

Now to really focus on road noise, I bet pulling out the
plastic inner fender panels and coating the clean side with the paint on material is effective , plus wherever you can get to inner
fender metal with some dynamat or painting, while these are out.

It would be a full weekend project because the paint on stuff
has to be built up in coats.