Soundproofing

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TB2
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Soundproofing

Post by TB2 » Tue May 12, 2009 10:30 am

Hi there.

Has anyone ever tried to improve the BX' poor noise insulation? It's not a problem up to maybe 70km/h, but from 100km/h upwards it's not really pleasant to listen to music anymore. I looked at different options but they seem either ineffective or expensive or both.

I looked at these options:
- Alubutyl, very expensive, good sound proofing for the doors, to get better resonance from speakers. Not necessarily a lot of sound proofing from outside noise.
- Foam panels. A bit cheaper but only effective when using a lot, so it's still pricey.
- Bitumen panels. Very ineffective.

Asking in a hifi-forum someone also told me that there might be a range of things that are different in a newer car that make it less noisy compared to a BX, some of which I could add myself, if I new which materials to use, but most of which are impossible to improve:
Underbody encased
Double bulkhead
foam panels under carpets (can do this?)
Rubber suspended body on chassis frame
Double or tripple door seals (can do this?)
Window glass with coating
Wheel cages with plastik casing
Seals inside body seams to reduce stream noise
So, has anyone improved the sound proofing on a BX before? What materials to use? How much better can it get? Is there any potential?

By the way I'm impressed how silent the inner of the car is. No rattling, as in many other cars of that age. It's pretty rock solid :)
Carl

1989 TRD "Entreprise" Turbo Diesel
1989 16 Valve
---
Parts needed:
- One black leather headrest.
- FDV overhaul kit (95.669.034)
Please contact me through PN if you have any of this.

roody262
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Post by roody262 » Tue May 12, 2009 10:55 am

I've never tried it myself, there is however a short paragraph on the topic Here

retrodriver
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Post by retrodriver » Tue May 12, 2009 11:06 am

Have a look here:

http://www.fiatforum.com/500-guides/165 ... r-pan.html

Its for a completely different car but the principle is the same and according to the author he has registered some accurate readings showing good improvements.
Alex


1991 BX 16 TGS 104k miles, FOR SALE
2007 Grande Punto Sporting

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MULLEY
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Post by MULLEY » Tue May 12, 2009 7:23 pm

It would be interesting to have a ride in a bx thats had some extra soundproofing done to see if its worth the effort.
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mountainmanUK

Post by mountainmanUK » Tue May 12, 2009 8:05 pm

I've been thinking about trying to improve the soundproofing on Monica for a while. After seeing those links I may be tempted to give it a go later this Summer.
I was amazed at the increase in noise levels inside the car, simply by omitting to correctly refit the little rubber grommet thing on the pedal end of the clutch cable. Lots more engine noise coming through that little gap!!

I still havn't got it properly sorted, as the rubber is very tatty and won't fit right....but I believe that they are still available from Citroen.

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TB2
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Post by TB2 » Tue May 12, 2009 11:14 pm

Well well. My vacation starts in a couple of weeks. I'm determined to do something about the noise. I'll see what happens. The Fiat guy also used alubutyl on the floor.
Carl

1989 TRD "Entreprise" Turbo Diesel
1989 16 Valve
---
Parts needed:
- One black leather headrest.
- FDV overhaul kit (95.669.034)
Please contact me through PN if you have any of this.

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docchevron
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Post by docchevron » Wed May 13, 2009 2:04 am

I found a really easy way of improving the sound deadening of the car.

Install a pair of 6x9's and stick some MUSE on fooking loud. Job done.
Smokes lots, because enough's enough already!

Far too many BX's, a bus, an ambulance a few trucks, not enough time and never enough cash...

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maxgreenwood
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Post by maxgreenwood » Wed May 13, 2009 2:22 am

yeah i've been thinking about this one. Its one of the main reasons i'd opt for a more modern car.. for better music listening conditions, although the setup in the TZD is pretty good and would be better with better speakers in my case, i can't help feeling an extra layer of dense foamy stuff in the doors/footwells/bulkhead/firewall would improve things no end.

i recently left my car overnight in a church carpark.. don't ask.. ok it was after a gig in there.. and returned the next day to find my r/h wing mirror carefully placed on my bonnet. couldn't believe it, been taken straight off by some unobservant fool. Luckily my 17TGD was wating at home with a donor. So while i was fitting it was quite interesting to see the innards of the door. I reckon theres definately scope for a big sheet of something dense and spongy to add to the door, similarly under the footwell carpets, bulkhead not sure how to get at that one.

I'd be very disappointed spending time to source the materials and the hours to dismantle/assemble and there be not that much difference.

I'm sure theres a member on here has mentioned they have done quite extensive extra soundproofing with success?

let thee be known :)
'92 16TXS (m), Dark metallic green, 74k
'90 16TZS (m), White, 86k
'89 19TRS auto, Olympic Blue, 133k
'88 Saab 900 8v Turbo (auto) 107k Red with Tan leather, lovely drive and well maintained.
'07 Hyundai Santa Fe 2.2 CRDi 85k (m). Practical family wagon

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docchevron
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Post by docchevron » Wed May 13, 2009 2:25 am

There's huge scope for sound deadening in the doors, in the scuttle, behind the dash, pretty much everywhere actually.

Also, modern sound proofing shit is infinetly better than stuff of old, and thinner, so whapping some sheets under the carpets can pay massive dividends.
Smokes lots, because enough's enough already!

Far too many BX's, a bus, an ambulance a few trucks, not enough time and never enough cash...

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maxgreenwood
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Post by maxgreenwood » Wed May 13, 2009 2:28 am

lets get some more data on this modern soundproofing shit doc, i'd be interested
'92 16TXS (m), Dark metallic green, 74k
'90 16TZS (m), White, 86k
'89 19TRS auto, Olympic Blue, 133k
'88 Saab 900 8v Turbo (auto) 107k Red with Tan leather, lovely drive and well maintained.
'07 Hyundai Santa Fe 2.2 CRDi 85k (m). Practical family wagon

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Post by kiwi » Wed May 13, 2009 6:16 am

Another less obvious route to follow in sound proofing is remove the cause!

Tyres are a first step and what tyres you have fited makes a differance but then so does the road surface you are driving on. I recently changed my front tyres and have noted a distinct lowering of Road Noise or certain sections of the roads I navigate.

Of course improving with some of this modern shit stuff Doc refers to will also help.
1991 BX19 TZS 04/01/91 (Deceased)
1990 BX19 TRS 27/10/89 (Reborn)
1992 BX19 TXD (Ex UK - K 744 SDF) 15/06/92
1990 BX19 TZS Auto 06/11/1989
1992 BX TZD Turbo Estate (Ex UK) 1/07/91

roody262
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Post by roody262 » Wed May 13, 2009 10:49 am

There is a company called dynamat who make sound proofing material, they sell it in large rolls or small kits just for speakers. I saw a video of a guy testing its effectiveness by putting it on a symbol from a drum kit and hitting it, the results were very impressive.
I've seen it for sale in Halfords and also online car audio retailers such as http://www.caraudiosecurity.com

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Kitch
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Post by Kitch » Wed May 13, 2009 11:16 pm

Sound proofing all adds weight. I've got quite an extensive Alpine setup in my car and I love the sound quality. It's fine on the motorway too....in fact it drowns out the drone of the engine. Valvers aren't motorway cruisers!

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Post by Way2go » Thu May 14, 2009 12:09 am

Kitch wrote:Sound proofing all adds weight.
Very true! The best soundproofing material I've seen (heard :) ) is a dense rubber in sizes of 3 and 5mm thick rolls. The 5mm stuff was demoed made into a Top Hat that was big enough to totally encase a 100 watt speaker that was blasting out music. With the 'Top Hat' placed over the speaker the sound was inaudible apart from the odd sybillant.

I hate to think what the weight would be to cover the whole interior of the car in this stuff besides what the cost would be. :shock:
1991 BX19GTi Auto

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docchevron
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Post by docchevron » Thu May 14, 2009 2:30 am

Dynamat do indeed do some rather good sound deadening shit.
There's a company that supplies body builders (commercial stuff) we use in work, cant for the life of me remember the details off the top of my head, but I'll ask the Engineering director next time I'm passing.
Weight is a tad of an issue, but thats dependant on how much you add to the car I guess.
There's some pretty good lightweight stuff about now.

Tyres do have an effect fo shizzle, but I've been using Uniroyal Rallye 550's for years now, and wouldn't use anything else so tyre noise is way less of an issue for me.
Infact non of it is really an issue for me since I never drive without the radio on, Radio 4 or some shit on CD.
The general accusticts of the BX tends to amplyfy alot of the noise so adding small bits of stuff in strategic places is almost certainly better than plastering the whole car in shit anyway TBH.
Smokes lots, because enough's enough already!

Far too many BX's, a bus, an ambulance a few trucks, not enough time and never enough cash...