Sound deadening question

Good Vetrens Day afternoon all,
I have my back seat out of my 11 Scab and an getting ready to do some deadening before installing my audio system. My plan was to do the back panel and the rear part of the floor. I'll do the doors when I upgrade speakers later.

In general, the truck is fairly quiet, but I can hear the exhaust drone from the back. I'm going to install some Second Skin CLD over the areas where I can get to the back panel and attempt to cover as much of the area with Mass Loaded vinyl as possible too. Then I got to thinking (usually means more work for me) that I might as well pull the front seats and do the floor too. THEN, I taped on the roof, and it really rings. Where does it end?

My question, probably Noah would know the best answer, where is the point of diminished returns in sound deadening? Noah, As a rule, how far do you go in your shop on sound deadening from a cost/benefit perspective?

TIA

@The Car Stereo Company

I'm interested in what can be done with the vents in the rear of the cab. Is it possible to put acoustical foam over these? I plan to tackle this in the spring.

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Thanks all,
Im tackling the floor now. I have all the seats out and the back panel covering. I was also wondering what to do about the vents too. I have some poly fill from a speaker project left over, so I may try to make covers with that for the vents. It wont kill all the sound, but it may help out while still allowing some air flow. Since I have everything else out of the interior, it would be the best time to do the roof too.

JanT, did you notice much difference doing the roof? The headliner does seem to block a lot of noise but the sheet metal sure rings when you tap the top with a fist.

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sorry, mia most of yesterday. as a general perspective of how much sound deadening we use, we typically use 4 rolls of sound deadening for the crewcabs and slightly over 3 rolls for the supercabs. without a moonroof, it will be a little more. each roll is about 36sq ft. we cover as much metal as we can. roof, floor, back wall, both layers of metal in the door, anywhere theres metal that can be covered.

The Car Stereo Company said:

sorry, mia most of yesterday. as a general perspective of how much sound deadening we use, we typically use 4 rolls of sound deadening for the crewcabs and slightly over 3 rolls for the supercabs. without a moonroof, it will be a little more. each roll is about 36sq ft. we cover as much metal as we can. roof, floor, back wall, both layers of metal in the door, anywhere theres metal that can be covered.

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And about how much does that cost and how long does it take, Noah?

Ruger said:

And about how much does that cost and how long does it take, Noah?

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cost depends on material. there are cheaper brands of sound deadening out there. most are all the same. butyl rubber with aluminium sheet. these can range in thickness and thats why theres varying prices. dynamat is the most popular. i think it runs about $800 in material. other brands are hushmat, roadkill, blackhole, etc. i prefer the focal stuff because it has additional layer of insulating foam. for n even quieter ride. however the cost is twice as much as dynamat. roughly around $1700 in material. but focal as tested their product in their lab, and anything focal is going to be well worth it. when you figure in the labor the entire process will take a day to a day and a half. at the shop it was a $3,000 job including materials. (and wonderful ca sales tax)

Ya, I'll be heading to Home Depot. Yikes!!!