Sound deadening trunk compartment-is it a big difference?

[jazma]

Ok, so I have a 2dr facelift e30 M40. Technically stock, so no loud exhaust etc. Due to my recently revived interest for car audio, my sound deadening project has gone out of hands way more than I originally planned. But still I would like to have a quieter ride. Too late to back up now.

I've already used Dynamat on front doors and bonnet. I've also used a cheaper option for Dynamat called Vibroplast starting from firewall and going all the way to the rear shelf. Door and rear panels have been treated with about 10 mm thick foam sort of material.
It's a lot quieter now overall. Especially the front door treatment made a big difference. My car has the usual M40 ticking faults and maybe I'll put second layer of Dynamat to the bonnet. But that's not the point here.

Areas that haven't been covered yet with anything are: roof, rear compartment and rear quarter panels. If one should select the next area to be worked on, what would you recommend based on your experiences? Which of these areas makes the biggest difference on reducing noise?
For some reason, the rear compartment isn't high on my list due to the separating wall between passenger and trunk compartments. Although using Dynamat on rear wheel wells would definitely reduce tire noise. If my car would be e.g. mk2 golf, the rear area would be first on my list.

Suggestions, anyone?

[oli325]

on mine i dynemat'd from the base of the rear seats all the way to the rear lights,both sides of the rear fire wall,double thickness on the rear boot floor and spare wheel well,it made a big difference in audio quality and reduction in road noise the only draw back was the weight of the stuff

[davemi16]

hmmmmm, I'm installing a system in mine atm, I'm in two minds whether or not its worth doing, as ive never heard a before and after with soundproofing fitted.

Is it worth the cost and does it actually make that much of a difference to sound quality/bass

[oli325]

the main reason i did mine was because i got hold of o box of dynamat really really cheap,buti did notice an improved sound quality and volume

[barny]

hi ive done mine all over in boot and sides and and floor it makes a big big difference !!!! no road noise and also sound from install, so loud inside car but on out side you cant hardly hear it and you dont look like a tw*t with it turned right up lol

[harry_p]

do the roof. amazing how much difference it makes.

ok, so i went the other way, i stripped al the sound deadening out of a car, but still.

individual areas didnt seem to make a single huge increase in noise untill the roof was stripped. instantly the car sounded a whole lot more tinny and drum like.

seems silly spending all that time and money doing the low down bits, and ignoring the big thin metal skin close to your head. if you've done the floor, rear seat / rear bulkhead, i can't see that doing the boot would make a huge difference.

[miniblob]

Doing the boot will make a difference - presumably there are subs in there???? No point it just vibrating the cars panels!!!

Sound proofing does make a difference!!

I didn't want to do mine because of the weight it adds, but i thought about it and am definately going to be putting plenty of deadening all over!!