Thread: Soundproofing my 90!

Having driven my 90 for a few thousand km, I thought it was time to make it a more pleasant environment to live with, especially with reducing the road noise! After much reading on here and other forums, I decided on a strategy, fitting Dynamat Extreme, then a mass loaded vinyl, then a quality carpet with sound deadening properties as well!

The whole lot has been work in progress for several months... I went through a phase of wanting to leave the rear seats out and just install a rear cargo drawer leaving me with a lovely flat floor! But having driven around without seats for a couple of months, the practicality of that waned and I decided to proceed with the rear seats installed!

So, first job was to remove the rear seats (heavy!) and all the associated hardware! Dynamat installed, very sticky stuff so you have one go to get it in the right place! I made templates for the forward end of the wheel wells and over the fuel filler cap. Being summer, it was lovely and sticky from the get-go, but a good hard roller ensures a nice finish!



It took 2 full packs to do the entire area, minimal wastage.



Once the dynamite was down, it was much quieter! I was very surprised how such a thin layer worked so well, stopping the panel vibrations and resonance makes a big difference!



Then came the mass loaded vinyl. Lots to choose from, but I finally settled on a product made by Pyroteknc in Sydney called Wavebar Quadzero. I chose the 4KG/meter version... It's only about 2mm thick and quite flexible. It offers a big jump up in sound absorption from the 2kg stuff, but is nearly as effective but is not as thick as the 8kg/meter version which was 5mm.

I use my carpet sections to mark up then cut out templates for the Quadzero. Easy to cut using a craft knife. I then used SikaFlex contact adhesive to secure this in place over the top of the DynaMat. I did this outdoors with all the windows open and a respirator mask on as this glue stinks! Again, the contact adhesive is VERY sticky so definitely a once only chance of getting it in the right place and alignment from the get-go! As a 'one man job', this was challenging as it's heavy too! One side done!



All done!



The combined thickness was now the Dynamat plus the Quadzero! Too think to re-install the seat frames to line up with the holes, so I cut around these and peeled off the Quadzero leaving just the Dynamat. This was perfect.



Next came the carpet install! I had decided to use the great product made by LRI in the UK. Apparently it is Jaguar carpet, it's certainly a nice quality. In view of the fact that I may want to remove the carpet for cleaning or access, I decided not to use contact adhesive, but rather industrial strength double sided tape to fasten it in place. Some careful measuring up using 4 lengths. Despite the self stick of the tape, it was till not enough too really stay secured to the back of the carpet, so I once again used contact adhesive to secure the tape to the carpet face.





Both sides now installed. Some very minor trimming required but otherwise a perfect fitting carpet from LRI. The only pieces not included for some reason were the wheel arch faces and the fuel filler neck. I bought a small piece of black automotive quality carpet and using the same templates I had used for the dynamat, I cut out pieces to suit and contact adhesive these in place.



The floor piece is thicker and comes with a sound deadening material backing. Once again, this fitted perfectly with no trimming required. Very impressive from LRI, thanks!



Finally, got the seats back in, heavier to re-install by myself! I finished off the job by replacing and installing the rear door 'kick strip' with lovely brushed Stainless Steel versions from Brendan at 4X4 Overland in the UK. Spot on fit and looks very smart!



Really pleased with the whole job! Not only is the Defender MUCH quieter now (my other half even commented on it!) but it looks really great too! Plans now to do the front in the same way!

Cheers, Pete

Nice job... looks almost "County" spec with carpet in the back :P I have got seats out at the moment and couple of packs of dynamat extreme that arrived last week so am about to embark on the same job.

I was planning on doing extreme in the back and doors, with extreme followed by dynaliner over the transmission tunnel and roof to reduce heat. Did you do any sound measuring with the different layers of insulation beyond the rudimentary stereo volume at 100km? Specifically do you think the gains of the mass loaded vinyl worth the effort/cost/weight over the dynamat extreme and carpet alone?