I wouldn't dare recommending things but yes this is what I used and it got pretty silent!

I just installed new speakers and put flashing tape in all round. Does provide some improvement in sound deadening... possibly not as much as proper stuff, but then it only cost £15 and I've got 1/3 left over.

I have just been told that foam camping/sleeping rolls work great. Can anyone confirm this?

Sensible + points
It's closed cell and does not soak up water.
It's quite dense so has a good ability to cut noise.

I think they sell them in the pound shop and would make the floor nice and soft

To revive this thread, I'm doing this sometime this week hopefully. Having read through this thread I'm none the wiser.

From what I can gather, flashing tape will reduce vibration of panels. If this is the case, why is it being used as sound deadening? It looks too thin? Dynamat has been said to be too expensive for the results you get but I'm not seeing a viable alternative from what I've read so far, unless I've got flashing tape all wrong?

What definitive product should I use to reduce noise inside the car? I'll be applying whatever material I go for to the roof, door cards, rear panels, under the rear seat and the floor pan.

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ETA - Having just seen the price of dynamat they can jog on!

Flashing tape reduces or kills resonance, which is a source of noise in itself. And yes it's thin, but it's better than just a 0.2 mm sheet of tin or plastic.

There are however plenty of materials to choose from, and there are indeed cheaper brands than dynamat. Do a search for "Peel & Seal".

These come up as good alternatives as well:
http://www.mcmaster.com/#9709t39/=bjlpmj
http://www.edesignaudio.com/index.php?cPath=1_24
http://www.b-quiet.com/vcomp.html (lcomp was supposed to be slightly better but contains leadwhich has risen very much in price)

All those mats are mostly just bitumen so not very different from regular roofing material. Without the gravely layer. The alu foil is meant to get rid of the heat (noise is converted to heat). That's the theory.

Yes but does it actually reduce outside noise infiltrating in the cabin, or does it just stop structural noise (which I dont experience with my coupe)?

You'd be surprised. But as a sound absorber it will only stop high-frequency noise (airborne) and stop low-frequency transmitted noise ('parasitic' vibration).

Check out the vcomp though, that is quite effectove for low frequencies as well.

Like I said if you have a read of this it breaks it down for you.

http://www.sounddeadenershowdown.com/cgi-bin/index.cgi

Flashing tape would be what they call the CDL tiles part.

Have a look on Ebay for the closed cell foam and Mass Loaded Vinyl. I'm trying to find a cheaper way to do the second and third parts but I'm having no luck.

That looks like a really useful link. Thanks! I'll have a read

Im in the process of looking to do the whole of my misses coupe so its ultra quiet and like you all know the price of sound deadening is very expensive so il just keep an eye on this thread

BINGO!

Here's the closed cell foam. I've just ordered 4 rolls with free P&P.

Now I just need the MLV.

That's a great idea, I'd be interested to see how well this works - please report back!

like I said check out the pound shop for these.

Do make sure though that the pound shop ones are closed cell foam (not the cheaper open cell) and check the thickness.

The missus has informed me they are closed cell with a smooth surface. Dont know about the thickness though.

An automotive OEM I have worked for uses Porofib (http://www.hordastans.se/?articleId=73&lang=UK&topId=6.4) and Lamiflex (http://www.hordastans.se/?articleId=74&lang=UK&topId=6.4).

I believe partially closed cells are the way to go then it comes to foam. The foam business is tricky since not all foam are good sound absorbants. The best bet is to use recycled textile fiber such as Porofib. Got both kinds which I have applied to rear quarter panels and door panels.

Need something for structurally borne sound as well though, such as these: http://www.hordastans.se/?articleId=75&lang=UK&topId=6 to sheet metal. For example, under the rear seat.

Generally I would recommend a good technical foam or textile fiber applied to the inside of the plastic panels for absorbtion and heavier stuff such as the ones showed in the second link structurally borne sounds for body panels.

<edit:> After looking around, bitumen-based heavy layer mats will be the plan for me for body panels, should be readily available in the UK as well.