mseriously

I've read a lot of stuff and been through a ton of threads on sound deadening and quieting up the engine noise...but what I never get is how much to use and where to use it and if it even works? Some use a little here and there and some tear the whole interior apart and paste everything.

Do I need to go overboard on the whole vehicle? Should I just stick to the front engine bay and firewall? I do plan on putting in a decent stereo set up, so should I just go all out?

Looking for opinions and help...

JIMXB

It all depends on how much of a audiophile you are and how deep are your pockets. For, it can get very costly $$$$ to do your doors, floors + headliner for supreme sound deadening. For example, applying Dynamat to the doors of your vehicle can reduce road noise from 3-6dB. Complete coverage of an average vehicle can reduce road noise 9, 12 even as much as 18dB.

As for me, I have 3 amps + about 2,500 watts with a lot of speakers, no dynomat. I just turn up the volume+ I haven't reduced my savings problem solved , LOL
"Good Luck on your decision"
Decibel (Loudness) Comparison Chart
Here are some interesting numbers, collected from a variety of sources, that help one to understand the volume levels of various sources and how they can affect our hearing.
Weakest sound heard 0dB
Whisper Quiet Library at 6' 30dB
Normal conversation at 3' 60-65dB
Telephone dial tone 80dB
City Traffic (inside car)85dB
Train whistle at 500', Truck Traffic 90dB
Jackhammer at 50' 95dB
Subway train at 200' 95dB
Level at which sustained exposure may result in hearing loss
90 - 95dB
Hand Drill 98dB
Power mower at 3' 107dB
Snowmobile, Motorcycle 100dB
Power saw at 3' 110dB
Sandblasting, Loud Rock Concert 115dB
Pain begins 125 dB
Pneumatic riveter at 4' 125dB
Even short term exposure can cause permanent damage - Loudest recommended exposure WITH hearing protection140dB
Jet engine at 100' 140dB
12 Gauge Shotgun Blast 165dB
Death of hearing tissue 180dB
Loudest sound possible 194dB
Perceptions of Increases in Decibel Level
Imperceptible Change 1dB
Barely Perceptible Change 3dB
Clearly Noticeable Change 5dB
About Twice as Loud 10dB
About Four Times as Loud 20dB

Sound Levels of Music
Normal piano practice 60-70dB
Fortissimo Singer, 3' 70dB
Chamber music, small auditorium 75 -85dB
Piano Fortissimo 84 -103dB
Violin 82 - 92dB
Cello 85 -111dB
Oboe 95-112dB
Flute 92 -103dB
Piccolo 90 -106dB
Clarinet 85 - 114dB
French horn 90 - 106dB
Trombone 85 - 114dB
Tympani & bass drum 106dB
Walkman on 5/10 94dB
Symphonic music peak 120-137dB
Amplifier, rock, 4-6' 120dB
Rock music peak 150dB

CanxB

Doing the whole thing in Dynamat is overkill. A lot of good reading at http://www.sounddeadenershowdown.com/cgi-bin/index.cgi

I used a combination of Polyfill, dynamat, closed cell foam and rubber underlay
Large bag of fill for the hatch. > $20
One queen sized quilt fill cut in two of each rear quarterpanel. >$20
Total of about 60 ft of dynamat bought in two different purchases off Craigslist $60 + $30
80 sq ft of closed cell sound insulation for hard wood floors- freebie
80 sq ft of rubber underlay $40

Total cost of about $160

One of the best improvements was stuffing the hatch with poly-fil ( the stuffing in pillows. Get the big bag at Walmart for < $20 and stuff it all in the hatch and you will be amazed at the amount of noise it reduces. With sound deadening every little bit helps. I started with the hatch and then did the rear floor and rear wheel wells. Knocked down the exhaust noise so much that all I could hear was the motor. Next was the doors, this was a major improvement in the feel of the car because the doors did not feel or sound like a tin can when closing anymore. At this point and then I did the rest of the floor with small pieces of matting in areas where the metal was more likely to generate noise and laid closed cell foam (hard wood floor sound underlay) and a rubber matting (underlay for concrete floors) as a blocker to the whole door from hatch to firewall and now the exhaust is the loudest thing again but at a MUCH lower level. Now I have only the roof to do sometime in the future. I have noticed improvements with each area done and it is starting to get pretty quite inside and the bass is MUCH cleaner!

scion50bx

What do you mean by stuffing the hatch? i have '05 Scion Xb.

mseriously

The cover that goes on the back hatch door comes off and you can stuff the inside with polyfill. I've done a bit and noticed a minimal change.