Having just decided (actually the wife decided for me) I need to moderate the low rev boom I get from my back box I did a scan of previous posts and saw that dynamat was one of the common soundproofing cures proposed. Tootled off to the local ICE shop to get some but was told that dynamat will probably make any low frequency noise boom worse. Can anyone comment on using dynamat to reduce cabin exhaust noise or maybe suggest an alternative if the ICE guy was correct.

Having a five door probably makes it worse

 

I'm floundering a bit here, but I think Dynamat is used to reduce the higher-frequency noises coming from your panels. The traditional selling stand for it has two cymbals: one with, one without dynamat. One with Dynamat goes "thunk", not "ting".

He could be right, but I would think that anything you can do to insulate the noise would be good.

It may be worth just putting down more insulation material under the carpets first? It really depends how the sound is getting through. If it's airbourne, you're knackered but if its resonating through panels then dynamat may help.

In short, I dunno. Suck it and see.

Not a great deal of help. Sorry.

 

Thanks Nick. I'll start as you suggest by filling the spaces around the spare and then adding a layer of "some material yet to be dermined" over / under the load space tray. If I get +ve results I'll post back.

 

I had the same problem after purchasing SS back box, I purchased some high quality carpet underlay placed this under the carpet in the boot and in the tyre well, it worked great.

 

Bubble wrap works good on MY97 WRX 4 door.

Gethin.