Forester Soundproofing

Forester Soundproofing

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Discussion

corvus

Original Poster:

431 posts

151 months

Thursday 22nd August 2013
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I love my Forester. After owning for around three months I don't regret the decision to buy it. It's good in almost every way, but there is a fair amount of road noise. I've already had the front doors apart, fitted decent speakers and installed soundproofing to the inside of the them in the form of damping pads and closed cell foam, and it's made a big difference to sound quality.

Does anyone know where I can obtain sheets of self adhesive soundproofing for a good price? I plan to do the boot floor and spare wheel wheel. Any tips as to the best places to cut some road noise would be appreciated. I'm not after Lexus levels of hush, just an improvement. Thanks.

Edited by corvus on Thursday 22 August 12:40

Ved

3,825 posts

174 months

Friday 23rd August 2013
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Dynomat perhaps?

corvus

Original Poster:

431 posts

151 months

Friday 23rd August 2013
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Ved said:
Dynomat perhaps?
I would Ved but it's damn expensive. I think I'll just use the same supplier I got the last stuff from and go for a foam in a thicker grade. I used Silent Coat as the deadening pads in the front doors and was very impressed. It's cheaper than Dynamat and does the job.

Ved

3,825 posts

174 months

Saturday 24th August 2013
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Might have to look at this too for my own. The wind noise in the little triangle window runner that's next up!

benharry

7 posts

130 months

Saturday 14th September 2013
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I used these in mine - http://www.bodykitsonline.co.uk/impreza_shop/audio... You would need about 4 packs to really to town, but a couple of packs would go around the boot floor and bootlid. I used all 5 sheets doing front doors and bootlid and a little bit inside quarter panels in boot.

adingley84

337 posts

161 months

Thursday 24th October 2013
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05 Forester 2.5XT. Currently at 85k.

Still pulls brilliantly, gearbox and clutch feel good but suspension knocks a bit over rutted ground. Prob needs some new bushes as had had a pretty hard life with heavy loads more than a few times.

The wife says 'we need to replace it soon'. But i'm thinking 120k miles would be good the way its going!

DJFish

5,917 posts

262 months

Thursday 24th October 2013
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http://www.screwfix.com/p/flashing-tape-225mm-x-10...

This stuf is a good alternative to the 'professional' sound deadening products.

corvus

Original Poster:

431 posts

151 months

Thursday 14th May 2015
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OK, so I was disappointed with the level of noise in the car, and decided to do the front doors, as mentioned above.

Put it all back together, and it made quite a bit of difference to the noise coming through the doors. It made the speakers sound better, and I have no vibration from the panels when turned up.

The car was still plenty noisy in other areas though. With soundproofing you really have to treat quite a few areas before making much of an impact. The trouble is, after reading various threads on the Forester forums, everyone is of a different opinion as to where all the noise is coming from. My aim was to reduce road noise. Wind noise doesn't bother me and I doubt that you could do much given the Forester design.

The best material for blocking road noise seemed to be mass loaded vinyl, with a thin layer of foam used as a decoupling layer. MLV next to metal doesn't work. So I bit the bullet and ordered some SBM5, a 2mm mlv that was good value for money and easy to cut. And more 3mm ccf.

I removed the interior trim from the tailgate and boot sides and added deadener (silent coat) to the outer panels. These panels really resonate and sound very tinny, and I treated them enough to produce a dull thud rather than a hollow sounding ring. I stuffed some acoustic foam into the tailgate cavity, the tailgate interior panel and the hollow sides of the boot before putting it back together. I'm not sure how effective this foam is, but it's supposed to absorb sound reflections.

I cut a piece of SBM5 using the boot floor sections as a template, then just laid it down on top of the boot as a liner. You can go underneath but it means a lot of cutting and messing around to get it to fit in the spare wheel well, and having it on top meant I didn't need to use foam as a decoupling layer.

The other area that looked bad for noise was under the rear seat, as this has no soundproofing at all, just bare metal. Although you can see that Subaru added deadener to this area. I took out the rear seat cushion, covered the metal floor in foam to just behind the seat back area, and cut SBM5 to fit over the top, also cutting to allow any fixings to poke through. There are two small areas of exposed wheel arch on either side, I covered these too. And put it all back together again.

The SBM smells a bit rubbery when first unpacked, but it seems to have dissipated, and I only did the car a few days ago. It doesn't bother me, and I have a very good sense of smell!

I went for a drive, and I'm very pleased with the results. Most of the noise I can hear now is through the doors, particularly the back, and they haven't been treated yet. It really has made a massive difference already, and I reckon once I give all the doors the same treatment, I won't have to do any other areas, it will be good enough for me.

The other unexpected bonus is the ride quality at the back. Instead of jolting over bad roads it flattens them more effectively. Mass loaded vinyl is very heavy and dense material - 5kgs per metre squared. I used around two thirds of a roll which weighed as a whole roll around 18 kgs. That's why it's good at deadening sound. Anyone looking to keep their car light don't use this!





Edited by corvus on Thursday 14th May 13:13


Edited by corvus on Thursday 14th May 13:13

74merc

594 posts

191 months

Friday 15th May 2015
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Interesting post, I have a Forester too and if a car needed to be sound proofed, it's it!
The difference in NVH between it and the Outback is night and day, and ruins the car for me. It's just too noisy for long motorway journeys.

corvus

Original Poster:

431 posts

151 months

Friday 15th May 2015
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74merc said:
Interesting post, I have a Forester too and if a car needed to be sound proofed, it's it!
The difference in NVH between it and the Outback is night and day, and ruins the car for me. It's just too noisy for long motorway journeys.
If you do the areas I've noted, you'll make a big difference, but you must use mlv as the noise blocking barrier - this is the stuff that really makes a difference. I've tried before with foam and it's not enough. This website is very useful and educated me

http://www.sounddeadenershowdown.com/home

v8250

2,724 posts

210 months

Friday 15th May 2015
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Corvus, just seen this thread. I too have an FXT but in 2.5 SG form. Dynamat is the preferred way to go though a little pricey. Interestingly, I find the biggest noise comes from the window seals and gussets + tyres. Have recently changed to Goodyear Efficient Grips running 225/50R17. The noise levels are superbly low. I can recommend these to anyone looking for good all round performance tyres. Window seals and gussets are a discussion for another day...

corvus

Original Poster:

431 posts

151 months

Friday 15th May 2015
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Thanks for the tyre tips. I'll keep that in mind when changing. I'm on 2 year old Vredestein Quadracs and they are pretty noisy on rough road surfaces. All tyres seem to get noisy as they age though.

TEKNOPUG

18,844 posts

204 months

Thursday 21st May 2015
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The vast majority of noise in a car is reflected off the road and up through the floor of the car. Quieter tyres will help but ultimately you need to invest in 3-stage soundproofing of the floor to hear real benefits.