Sound Proofing Defender 90 TD5

AJJackson1 said:

Right guys, I just spent £175 on products today and they will be delivered Monday and hopefully fitted pretty damn soon after.
I have done a few test runs and I seem to get between 95 and 100dB at 55mph with no sound deadening. I will report back with my findings early next week.
Just so you all know, my strategy is 100% 2mm silentcoat coverage, maybe double up on the big panels as suggested, 100% camping mat (closed cell isolator), 100% MLV.
I'm hoping for good results!

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exactly what im aiming for! one last thing you should do is:
3m tinsulate
3M Thinsulate AU4020-6-60 1 m X 1.524 m
im gonna put it in the roof space and anywhere else i can stuff it. especially behind dash as you can just stuff it in without removing entire dash!!
this stuff doesn't go on floor !!!
been researching this stuff and its what private jets and luxury boats use!!! will also keep you warm!!

AJJackson1 said:

Right guys, I just spent £175 on products today and they will be delivered Monday and hopefully fitted pretty damn soon after.
I have done a few test runs and I seem to get between 95 and 100dB at 55mph with no sound deadening. I will report back with my findings early next week.
Just so you all know, my strategy is 100% 2mm silentcoat coverage, maybe double up on the big panels as suggested, 100% camping mat (closed cell isolator), 100% MLV.
I'm hoping for good results!

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You sure that there will be enough space left inside for you?

Cheers for that g-mack! I will have a look and see if I can get some. I do already have a headliner so I'm hoping it's not entirely necessary but I like the idea of putting it behind the dash. I did wonder how I was going to get the sound deadening behind there as removing the dash is a right pain!
Boguing, who knows I guess it will be really quiet if I can't get in to turn it on!

So, I would like to say how excellent it is to have a nice quiet Defender,however, after spending 2 days filling my car with 40kg of soundproofing I can say that really, there is no difference from how it was before. The road noise is probably less but let's be honest it's nearly all engine noise in a Defender and that's very much still there. I imagine on the motorway it will be quieter but harsh accelerations etc are all just as before.
I recommend a louder stereo!

AJJackson1 said:

So, I would like to say how excellent it is to have a nice quiet Defender,however, after spending 2 days filling my car with 40kg of soundproofing I can say that really, there is no difference from how it was before. The road noise is probably less but let's be honest it's nearly all engine noise in a Defender and that's very much still there. I imagine on the motorway it will be quieter but harsh accelerations etc are all just as before.
I recommend a louder stereo!

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Hahaha that probably suits me then! i do like my music loud when im driving!

Youve also probably increased your fuel consumption, but hey landys seem to drive better with a bit more weight in them!

On a more serious note though mate is there anything you could suggest to do differently to improve results? What db levels are you recording now at 60mph?

I have gone for the music approach too. 1600 watts and 7 speakers seems to just about do the job!
I think you will be right about the fuel consumption. Not something I will look forward to at all. It will be a pain in the arse to remove it as well so it looks like it's all there to stay.
I really can't see that it can be improved easily. Somehow the noise needs to be stopped from coming in from the engine. The vents on the dash can't help but maybe that Thinsulate stuff will be useful but I doubt it.
I can say that the vibration reduction sticky panels are, in my mind, a waste of money. With a 50% coverage I heard no difference with the classic 'knock test'. With about 150% coverage the panel was a thick thud sound but I don't think panel vibrations was much of a problem in the first place.
I did a 2 mile test loop so I didn't get up to 60mph but full throttle and high revs is still around 97dB, before it was 101. This is classed as a 'barely perceptible change'

AJJackson1 said:

I have gone for the music approach too. 1600 watts and 7 speakers seems to just about do the job!
I think you will be right about the fuel consumption. Not something I will look forward to at all. It will be a pain in the arse to remove it as well so it looks like it's all there to stay.
I really can't see that it can be improved easily. Somehow the noise needs to be stopped from coming in from the engine. The vents on the dash can't help but maybe that Thinsulate stuff will be useful but I doubt it.
I can say that the vibration reduction sticky panels are, in my mind, a waste of money. With a 50% coverage I heard no difference with the classic 'knock test'. With about 150% coverage the panel was a thick thud sound but I don't think panel vibrations was much of a problem in the first place.
I did a 2 mile test loop so I didn't get up to 60mph but full throttle and high revs is still around 97dB, before it was 101. This is classed as a 'barely perceptible change'

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Well you dont know untill you try mate, im gonna say a big thankyou for sharing this useful information with everyone on here though. Youve certainly saved me a fortune and time. Ill not bother with it, i think like you say we just need to come up with something good of reducing engine noise.

Like you say vibrations and panel noises dont really bother me its just noise on the motorway which only comes from the engine.

Surely theres something amazing you can line the bonnet with like the insulation they use in an astronauts rocket or something haha!


As for the radio i have a td5 county 90 comes with cd player and four speakers two in front and two in rear. i have heard of upgrading to an alpine head unit but i was wondering do you know of any good direct replacement speakers i could fit? im after better sound quality and power but would be good if i could do a direct swap to save messing etc.

AJJackson1 said:

I did a 2 mile test loop so I didn't get up to 60mph but full throttle and high revs is still around 97dB, before it was 101. This is classed as a 'barely perceptible change'

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4dB is a big difference even though it doesn't look much on paper - Sound levels double every 3dB!

so covered all panels with silent coat, and most of bottom of car with mlv and its still no different?

Sambora8080 said:

Well you dont know untill you try mate, im gonna say a big thankyou for sharing this useful information with everyone on here though. Youve certainly saved me a fortune and time. Ill not bother with it, i think like you say we just need to come up with something good of reducing engine noise.

Like you say vibrations and panel noises dont really bother me its just noise on the motorway which only comes from the engine.

Surely theres something amazing you can line the bonnet with like the insulation they use in an astronauts rocket or something haha!


As for the radio i have a td5 county 90 comes with cd player and four speakers two in front and two in rear. i have heard of upgrading to an alpine head unit but i was wondering do you know of any good direct replacement speakers i could fit? im after better sound quality and power but would be good if i could do a direct swap to save messing etc.

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No worries about sharing my findings, everyone's been helpful to me so I'm glad I can return the favour! For the blocking of engine noise I will say one thing. Make absolutely sure your vents are done up. I usually pull mine up until they are stiff, then lock them off. I yanked on them today until they were at the very top and that in itself made a 2dB difference!
With regard to the bonnet, apparently that is a good place to go. If you, like me, don't have the factory bonnet liner then apparently putting a liner in is good for a few dB Land Rover Defender Budget Bonnet Sound Insulation | FunRover - Land Rover blog & magazine

As for speakers, you are fortunate to have them as standard! Any single DIN headunit will have 4x50W output so unless you are intending to amplify your speakers you may as well keep the standard one. You will struggle to do a direct replacement as the nearside has negligible spare room due to the wiper motor. I made a spacer out of 20mm MDF but you can buy them from MUD UK. I made 130mm holes for 5.25 inch speakers. I would advise component speakers as you get a separate tweeter which you can mount on your dash, raising the soundstage dramatically. I stuck mine on with double sided tape as I did not want any more holes! Look at Car Audio Equipment | Buy online at Car Audio Security for a large range at good prices.
You can see my speaker setup/tweeter location in the pictures.

g-mack said:

so covered all panels with silent coat, and most of bottom of car with mlv and its still no different?

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I will go for a longer/faster drive tomorrow but essentially yes. I was a tad harsh and it is quieter but it isn't £170 quieter, more like £20 quieter if you know what I mean.

I have near 100% coverage of silentcoat on the front and rear footwells, bulkhead, and rear of cab. I have 50% coverage in the seatbox under the front and rear seats and doors, some parts of the footwells are 150 or 200% coverage.
MLV is 100% coverage in front footwells, transmission tunnel, rear footwells, rear seatbox and more than 50% coverage to front seatbox and rear of cab. There is also a 6-7inch strip in the bottom of the front doors and 80-90% coverage in the rear doors.
The factory sound deadening is then on top of that which is the thick rubber/foam for transmission tunnel, rubber mats in front and rear.

That's disappointing isn't it!! I guess it will be an expensive project to make significant improvements.
I bet if you topped it with a wrights matt it would help. That is what I will eventually do!
Another trick I heard for the bonnet was to get a full length chequer protector and fill the void with a few inches of mlv. I have a noise killer engine blanket too . Cost £120 for very little difference, but it helps a little!

http://pages.ebay.com/link/?nav=item.view&alt=web&id=251565100015

I was wondering about this not sure how it would fit or how good it would be on it its own.

Perhaps you could put a good coating of MLV to underside of bonnet then stick this cover on though?

My final update then. I thought I would try a baseline test yesterday and the result was quite interesting. I tested the background outside noise which was 58-90dB. I then sat in my Defender with doors and windows shut. It only decreased to 48-50dB! To give you a comparison, my Dad's 5 series took it down to 33dB. We will always struggle with Defenders, especially older ones, simply due to panel gaps. I would recommend ensuring they are good condition before forking out loads on sound deadening.
On a drive today I would say that road noise has certainly decreased, considering I have M/T tyres there really is a noticeable difference in that sector which is pleasing. The engine is still loud but when cruising the noise is down to 92-94dB from 98ish plus. Overall then, it hasn't been a complete failure.
Sambora, that cover looks like it has potential but I couldn't possibly say. Some people are saying engine blankets are the best upgrade you can get, others say they are useless. I think you would struggle bonding the MLV on to the carpet and may risk it melting with engine temps too. I would save a few squid and just buy some open cell foil backed foam for the bonnet. That is around £25-35 on eBay.

G-Mack, I don't have enough space for another mat! The doors already barely shut haha!

AJJackson1 said:

My final update then. I thought I would try a baseline test yesterday and the result was quite interesting. I tested the background outside noise which was 58-90dB. I then sat in my Defender with doors and windows shut. It only decreased to 48-50dB! To give you a comparison, my Dad's 5 series took it down to 33dB. We will always struggle with Defenders, especially older ones, simply due to panel gaps. I would recommend ensuring they are good condition before forking out loads on sound deadening.
On a drive today I would say that road noise has certainly decreased, considering I have M/T tyres there really is a noticeable difference in that sector which is pleasing. The engine is still loud but when cruising the noise is down to 92-94dB from 98ish plus. Overall then, it hasn't been a complete failure.
Sambora, that cover looks like it has potential but I couldn't possibly say. Some people are saying engine blankets are the best upgrade you can get, others say they are useless. I think you would struggle bonding the MLV on to the carpet and may risk it melting with engine temps too. I would save a few squid and just buy some open cell foil backed foam for the bonnet. That is around £25-35 on eBay.

G-Mack, I don't have enough space for another mat! The doors already barely shut haha!

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make sure you don't have any open holes in your bulkhead, and stick some proofing over the grommets. I'd also check your tappets and make sure your exhaust isn't blowing

Don't worry, Trax. I've got those grommets absolutely covered in sound deadening! Even the ones under the bonnet where the wires enter for the dash. It's just where the pedals enter teh cab that I can't fully insulate. I think my engine could do with a service so it may be worth looking in to, cheers.

I went to town on my 90 hard top... if you can get along to these guys near oxford, it's worth a trip, they did a great deal on some seconds. They know their stuff too and can advise as well as supply it all.
Acoustic products, sound absorbing products, soundproofing foam from Sound Service

I also splashed out on the Noiskiller The UK's Leading Land Rover Soundproofing Specialists | Car Soundproofing | Industrial Soundproofing | Marine Soundproofing underbonnet and cab insulation... haven't tried their engine/gearbox blankets - any reviews on them?

On top of all the insulation i've carpeted all metal surfaces with excellent results

Radio now at 7-8 instead of 10!

Don't forget the rear door... replaced it since soundproofing... and noticed the increased road noise... transferred soundproofing from old door, and trim... back to quiet ;-)

The only shame of my quest for a quiet ride was to loose the straight through mid pipe which gave a really sweet exhaust note... even tried the fancy cherry bomb type - still too boomey!

Good luck...

Bought my 2000MY Defender 90 TD5 last November and diesel noise inside was terrible.
Defender Diesel Interior noise comes from two major sources; Airborne into cab and Structure borne into cab.
Airborne:
First thing I found was the centre panel under the storage box was a loose/poor fit to the floor/seat panel. Took all that off and refitted with large self tappers with foam seal around edge, made first big difference.
Bought some Brushable Seam Sealer from Morris Minor Parts - E.S.M. Spares Part No. MAC030 and sealed all holes/gaps in floor pan/bulkhead (didn't remove all bulkhead covering just lifted up and poked around, but did remove floor mats etc.) - good water seal also! Cost about £24.00 (NB. Of course looked at other water leak sources as per the good old Defender Water Ingress manual as well)
Replaced front & rear door seals, again, airborne engine and road noise paths and of course water leaks. Do the "pull out paper strip test" to ensure seals are working!
Reduced Engine radiated noise with excellent material from
http://www.foamsolutionsuk.co.uk/under-car-bonnet-fire-retardent-foam, 1 metre square self adhesive, just about right for under hood, trim edges for improved appearance. Cost £25.00 Removed hood and stuck on underside; added some Fir Tree fasteners for added security from EBay firm Autoclipsdirect using Ford P44 type. Cost £3.50 Marked places on hood ribs and drilled thru; making sure drill had DEPTH STOP for obvious reasons! Sounding better already!
Took rear and front head linings down, 13 years old needed a good soap & water wash. That enabled me to use another Foam Solutions material. I went for the 2 x 1 meter x 6 mm CLOSED CELL (must always be) self adhesive sheet. Cost £31.00. Cut according to need, sticks well to underside roof panel (in the summer).
Closed cell foam to these surfaces reduces noise both radiated from "loose" roof panels and "absorbs" the higher frequency noises from diesel engine.

Structure borne:
This requires basically added MASS to the panels in form of damping pads.
Soundproofing & Acoustic Control - Sound Control Services offers good bitumen based damping pads, DM5, 2.5mm thick and 2 sheets 1mtr x 750mm for about £30.00. Want to get highest density without being too thick so can be formed (in summer) to floor areas. I made paper templates for floor foot wells, over transmission tunnel, removed seats and covered all of the seat box surfaces, including the battery and ECU covers. Then cut pads to shape and just stuck down.
Also had some of the foam solutions 6mm material left over which I put under the Land Rover floor mats.
I am very pleased with the result as although you know its a diesel still, that harsh cackle and diesel combustion noise has significantly reduced and one can converse with the passenger or have the radio on.
Total cost about £115.00 plus the satisfaction of doing it myself for half the cost of packages!

Nice one Morgan. I already have some new seals on the way as I can see through to the road outside if I angle my head properly. I'm hoping that will help quite a bit.
I like the sound of the bonnet foam as well so may get me some of that over Christmas.
I shall report back with my findings.

The comments on grommets etc are valid because partial covering is not a good indicator. Covering 90% does not lead to a 90% reduction in noise. One small 10% gap can allow 90% of the noise in