Dead Doors

[The Rigger]

Last night I got to stuff a double layer of Cascade Audio's VMAX dampening material in my Cabrio's doors. (I'm doing the whole car, but only had enough sunlight to get through the doors last night.)

John_H recommended the stuff, and I took him at his word. I stuck a double layer inside each door skin. He's right; the sonic characteristics of the doors as a speaker box are *vastly* improved in the low and low-mid end of the spectrum.

Just for giggles, I hooked up an RTA (real-time analyzer; one of my PA system tweaking tools) in the car and played a CD of pink noise over the system pre-installation to establish a baseline profile of the door, based on how I like the EQ set on my AVH-P4100DVD head unit. After installing the VMAX I re-ran the test, and found that I could drop the EQ settings a couple of points in the low and low-mid end of things (1.25K and lower) and still maintain my preferred curve, plus the dampened door smoothed out a couple of spikes in the EQ curve. I call this a big ol' *WIN*.

Today the seats and carpeting come out, and I'll finish VMAXing the rest of the seat pan, plus adding an I-12 "thermo-acoustic" insulation barrier layer to the firewall and engine cover, to drop the engine/road noise and control the radiant heat.

Stay tuned for gallery photos...

[forestacademy]

Don't forget to disconnect the Battery before yanking the seats, or you will need the trip to the dealer to reset those Airbag lights

[The Rigger]

Originally Posted by forestacademy

Don't forget to disconnect the Battery before yanking the seats, or you will need the trip to the dealer to reset those Airbag lights

Hm. I thought I read here that you only had to not turn on the ignition while the seats were out. I had planned on pulling the battery right out of the car and VMAXing the battery tray anyway.

If I have enough left over, I might just pull the front plastic and VMAX the tops of the front wheelwells.

[John_H]

I think I just had the cabin interior side of the wheel wells VMAXed, not the outside. Interested to hear your experience!

It is so cool that you have the audio equipment to compare. Glad to hear how good it compares!

I mistakenly turned on the ignition while the seat was out creating the airbag light issue for myself. If the ignition is absolutely left off, the airbag light should not come on. But disconnecting the battery is always "safe."

I'm thinking a battery cutoff might be a good investment for myself; I'm in the electronics enough.

Looking forward to the photos! Especially the seatless smart.

[The Rigger]

Originally Posted by John_H

I think I just had the cabin interior side of the wheel wells VMAXed, not the outside. Interested to hear your experience!

I looked at that, but I can't get my big butt that far under the dash. I settled for just doing the floor up to the pedals & wheelwells, plus the bottom of the battery tray.

I didn't have the tamperproof Torx bit to remove the brake pedal, so I wound up having to pull the front half of the carpeting over the pedal... *NOT* a fun point in the job.

Lemme tell ya, there are about a bzillionteen and six wires loomed up under the carpet, between the various and sundry brain-boxes, and (if you're smart) they all have to be pulled up off their threaded spikes, so you can get the barrier underneath. (if you're not smart, just ignore the previous sentence, glue your barrier right over the harness looms, and enjoy life until something Goes Terribly Wrong.) It took a *lot* longer to do the job than I initially thought it might, but the rule here is "measure fifteen times, cut & glue once." Then cuss yourself out, pull it up, reposition it, and put it back down.

Originally Posted by John_H

Looking forward to the photos! Especially the seatless smart.

Here ya go... Naked Cabrio.


Cabrio Under Wraps:


More in my SCoA gallery. Still more in my SmugMug gallery.

OBTW: I have a 4'-0"x 2'-10" piece of I-12 thermal barrier and a few sheets of VMAX left over. If anyone's interested, make me an offer.

[douglasmoir]

The Rigger,

Nice job on the install! The combination of Vmax and I12 is an excellent light weight thermo-acoustic treatment. Did you get a roadnoise reading on your rta for pre and post material application? My wife just ordered herself a Smart and I'm trying to convince her to let me apply an acoustic damping package. I also happen to be the product manager for Cascade Audio Engineering so I'm quite fimiliar with the products you used.

Regards,

Doug Moir

[John_H]

I'm happy to see a Cascade Audio Engineering guy and smart ownership come together!

The combo works great, indeed. I got my cabrio quieted before taking delivery back in May of '08. Seeing the car taken apart for sound dampening and for body panel paint was neat but a little more appropriate to October: spooky.

[AdamAtSCD]

i am planning on doing this too. so this material is lighter in weight than normal dynomat or some other comparable product? can anyone post up some links to where you guys are buying this stuff for good prices. Thanks!

[John_H]

Coming from Smart Center Denver, I'd think you would get wholesale pricing straight from the Manufacturer in Oregon: cascadeaudio.com. All I know about them I learned from researching sound/vibration dampening and buying their stuff.

I can't compare the products directly to dynamat. One of the large comparisons someone did ended up excluding the cascade audio engineering products from most of their tests.

The product is probably directly comparable on several points when compared within viscoelastic polybutyl rubber compounds with metal backing. Different manufacturers will have differences in the thicknesses or precise materials in the stackup as well as different adhesives.

I went with cascade audio because I liked the engineering evident from the writeups on their sites and was able to call the company and talk with one of the engineers about proper selection, coming up with the V-MAX and I-12 combo.

[The Rigger]

Originally Posted by douglasmoir

Did you get a roadnoise reading on your rta for pre and post material application?

In the lower ranges, I noted a general lowering of ambient SPL[1] between around 125Hz and 1KHz of around -3dB, with a sharp dip to -6dB at around the 600-650Hz neighborhood.

Overall SPL averaged across the audible range dropped from the high 80s to the mid 80s (dB, A-weighted), which doesn't sound like much, but as we know, a difference of -3dB equals roughly half the percieved SPL.

There's also a general lessening of sharp, bright, rattly sound, like the harmonic resonance of a vibrating chassis panel (which would be understandable) that was too quick for my RTA to react to, but is easily detected by my ears. I'd put it in the frequency range of that in the 2.5K to 5K neighborhood.

I'm quite pleased.


[1] "Sound Pressure Level," otherwise known colloquially as "volume."