Noise Reduction in my Defender 110 CSW

[popotla]

I’ve just finished fitting to my LR 110 CSW almost all the bits contained in the “Noisekiller” sound-dampening kit. As my expectation wasn’t high, I’m perhaps not too disappointed with the results. Suffice to say that the noise is far from “killed”.

My first question: as regards noise-dampening /”soundproofing”, is it a case of “the more the better” in terms of the depth of dampening material on any particular area? In other words, if I add more material on top of the Noisekiller sheets I’ve fitted, can I expect further improvement?

Second: most of the stuff Noisekiller supplied is 6-mm foam bounded on both sides by rubber app. 1.5 mm thick (total thickness 9mm). I don’t know whether this is high-, medium- or low-quality stuff in terms of its dampening abilities. (Maybe it’s very ordinary stuff sold at a high mark-up because it’s in “kit form”). To further improve sound-dampening, what kind of material should I look for? Please don’t suggest UK or other brand names or UK or other retail outlets as I’m not in the UK but in southern Oman and need to go hunting around looking at this or that kind of sheeting that building material suppliers or car accessory shops etc. might offer me. IS PLAIN THICK RUBBER SHEETING suitable, and if so what’s the maximum/minimum thickness to look for, or is foam bounded by rubber better (as per the Noisekiller stuff)?

Third: The Noisekiller kit contains pieces to be glued to or placed over parts of the seat boxes. Fitting the pieces on the front of the driver’s seat-box, under the vertical carpet covering appears to be not so easy, though possible (e.g. bolts retaining handbrake need undoing in order to release and lift carpeting). Does it make any difference in terms of effectiveness if the material is glued on the inside metal surface, i.e. inside the battery box, or must it be on the outside?

Fourth: Having heard that a lot of noise comes from/is reflected by a Defender’s roof, I was surprised to find that the kit contained nothing for the roof. Perhaps this is to keep down its cost. What would be the best stuff to fit to the roof, and can those plastic retaining studs be got out without making a dog’s leg of things?

Fifth: The Noisekiller kit contains a piece about 42 x 33 cm, designed to fit to passenger-side bulkhead. In the case of my vehicle, that will entail removing the air-con unit in order to get to the bulkhead wall behind it. I’m thinking that that will be troublesome and not easy, and wonder if I should go to the trouble.

Sixth: The NK kit contains some “pads”, thin, rubbery and foil-backed, and approx. 25 x 17 cm in size, to be fixed to the inside of each of the five doors. Are these small pads somehow supposed to reduce vibration/noise passing through the door?

I’m sorry this post is so long, but having come this far in terms of effort, time and cost, I feel I must do the job properly. Thus would much appreciate your advice regarding each of my points.

[gruntus]

Hi Popotla,

There has been a lot of questions on this in the path and a lot of various answers.

Essentially on my rebuild I have fitted a "lead blanket" sheet to my front bulkhead (not cheap) to cut out as much noise from the diesel and I will be fitting a Wright Off Road kit for the front floor pan that is highly recommened according to the feedback.

Feedback from all the stick on type sheets wasnt very favourable.

I cant let you know the results of the blanket (see attached) as its still a project but I was advised the two items above were the best way forward.

HTH

Cheers

G

[cackshifter]

Some years ago a chap designing truck cabs told me the most effective way to kill noise was with weight between you and the noise - hence use of lead engine covers. I've never had much success with using felt etc. I'd imagine the door pads are supposed to damp out generation of noise by drumming rather than stop noise passing through. I can't tell what is noisy apart from the engine because its very vocal, but I'd guess gearbox etc as well. My guess therefore is if you can get some weight (eg heavy rubber) especially on the bulkhead and over the transmission it'll make the most difference there.

Nigel

[Dave K]

I just take the children out & turn the radio up!

[DaveSIIA]

The law of diminishing returns applies to the thickness of sound deadening you can fit under the carpets. The Noisekiller kits provide a bit of weight to damp the panel vibrations and a soft(ish) core to reduce acoustic transmission.

In terms of sound transmission, the seat box is barely treated in comparision to the bulkhead and transmission tunnel of the 110. I would make the effort to apply the kit to the box, and on the inside of the vehicle. If it was on the underneath / chassis side of the panel then the material would need to be an absorber rather than providing damping, so would have a more "open" face.

The Defender roof panel seems to vibrate like a drum, so would benefit from some damping pads applied to the unbraced areas. The gap between the headlining and the roof panel could be filled with an acoustic absorber such as rockwool - only worthwhile if there is more than ~13mm gap otherwise there won't be much material in there.

The pad to go on the bulkhead behind the air-con unit is probably an attempt to reduce transmission through the bulkhead. It may or may not be significant in your application. You might get an easier return on your time by making sure there are no leak paths for sound to get through holes in the bulkhead and gaps in door seals, etc. Fitting a new foam seal to the battery box lid made a noticeable difference in my 300Tdi.

The thin pads are to damp vibration of the thin door panels and reduce acoustic radiation back in to the vehicle.

My Td5 110 CSW had a noise killer type kit fitted and made a ~10dB(A) reduction (subjectively halving the noise level) at motorway speeds. My 300Tdi 110 CSW doesn't anything more than the standard factory fit and is somewhat noisier. I plan on using conveyer belting (cut to size/shape) to treat all the floor panels and lower bulkhead. The seatbase will get particular attention, as will the floor under the middle row seats. The rear seats have been removed so the back will be completely lined to waist height and a loadbed liner fitted on top. This doesn't sound that scientific an approach, but I doubt Noisekiller did that much science either.

[popotla]

Thanks for these replies.

HTH, is all the foil-covered material in your photo sound-dampening stuff?

[gruntus]

Thanks for these replies.

HTH, is all the foil-covered material in your photo sound-dampening stuff?

It is, it has foil then foam a solid sheet of lead, more foam then the adhesive.

If you phone up noisekiller they will send you samples of all their products.

[bernie]

Hi,

I fitted Horse Stable matting thoughout the rear floor,wheelarches under rear seats, seat box and footwells in my 110 csw, it is 17mm thick and definately makes a difference, here in the Uk u can buy it for approx £30 for a 6` x4` sheet, which is a lot cheaper than Landrovers rubber matting for rear of vehicle. I would have thought that it could be purchased through out the world

[tychoS]

Hi,

I fitted Horse Stable matting thoughout the rear floor,wheelarches under rear seats, seat box and footwells in my 110 csw, it is 17mm thick and definately makes a difference, here in the Uk u can buy it for approx £30 for a 6` x4` sheet, which is a lot cheaper than Landrovers rubber matting for rear of vehicle. I would have thought that it could be purchased through out the world

I have been very happy with the ExmoorTrim kit.

It's made up of a thick, dense and very heavy lead/rubber type material. The matting is roughly 1 cm thick all over.

One piece covers the entire seatbox, you take out the seats, place the mat and replace the seats on top of the mat.

Another piece covers the floor and gearbox tunnel.

Finally a smaller piece to go around the fusebox and out into the vertical parts of the footwells.

It's not cheap, but can be fitted in 4 hours, where the majority of the time is spent removing and replacing the seats and making cutouts for handbrake elver, bolts for seats etc.

When driving with the top off, the vehicle is virtually noiseless, only a bit of tire noice is heard. With the tilt on, there is noice, but we can have a conversation up to around 90 km/t without shouting. This is with a 2,5 TD

[wanderlust4ever]

Hi,

I fitted Horse Stable matting thoughout the rear floor,wheelarches under rear seats, seat box and footwells in my 110 csw, it is 17mm thick and definately makes a difference, here in the Uk u can buy it for approx £30 for a 6` x4` sheet, which is a lot cheaper than Landrovers rubber matting for rear of vehicle. I would have thought that it could be purchased through out the world

Hi Bernie, what is the name of the company where you bought the mats.

Cheers mate

[bernie]

Hi Bernie, what is the name of the company where you bought the mats.

Cheers mate

Hi, I bought my mats through the well known auction site,

Company is Coruba, item no is 150 352 072 986

There is many other companys on there selling the same product throughout the UK,

I have had the mats in now for approx 3 months and are really happy with them, make sure you have a decent stanley knife to cut them with, i got through several blades.

[wanderlust4ever]

Hi, I bought my mats through the well known auction site,

Company is Coruba, item no is 150 352 072 986

There is many other companys on there selling the same product throughout the UK,

I have had the mats in now for approx 3 months and are really happy with them, make sure you have a decent stanley knife to cut them with, i got through several blades.

Many Thanks for the info.