Soundproofing?

The_Monk · 29th December 2006, 11:55

I had a quick search and couldn't find anything previous, so sorry if this has been asked before, but has anyone put any soundproofing in their 75's or Zt's?

Its mainly road noise at speeds over 50 that begin to irritate. I remember reading about the tyres can cause a lot of noise with them being 18" is this true? Would soundproofing actually reduce this noise on the floor of the car? I know doors, behind the dash should be done as well but the opportunity to do the floor will be available next month. Then hopefully over the next 12months the rest of the car could be done (funds permitting of course

).

Ken · 29th December 2006, 16:58

This is a good question and I am looking forward to any answers. I put sound proofing in the engine bay of a 45 and it made the engine noise a lot quieter but then I could hear the rear suspension! :lol:

If I did it to my 75 I would have to do the whole thing and not just the bay. To be honest I don't think its needed but the thought has crossed my mind

Ken

The_Monk · 29th December 2006, 17:54

I don't actually hear the engine much, not enough to distraction anyway. The road noise is getting rather annoying.

I had a search over on the .org site earlier after I posted, and a few different products came up, I didn't realise just how much weight was in them either till reading some of the posts. I dont really have the time to allow products to cure so i'm limited to adhesive mats etc... I can borrow my dads 75 its just finding space to store all the cars insides and I don't have a garage so curing would take ages in this weather!

M47Rman · 29th December 2006, 17:56

The basic NVH package, certainly on the original 75 was actually pretty good. A lot of work was done to 'tune' the engine and gearbox mounts to reduce vibration/harshness as much as possible, and also developing the accoustic pack. The twin wall bulkhead makes a huge difference to previous Rover cars, but and it is a BIG but, one of the things we found time and again, was that it only takes ONE plug or cable gland to be missing or incorrectly fitted, and all the hard work is undone. First thing to do is to ensure, as best you can, that all of the routes through the bulkhead, into the car, are sealed as best they can be. Any missing plugs or glands which are partially fitted should be rectified, and this will make a big difference. Also, make sure that the engine is not 'shorting out' on anything. If one of the engine mounts has been fitted incorrectly, with the engine being forced to sit in an artificial position, this will increase engine noise/vibration. This can be fixed by slackening off the engine mounts, and allowing the engine to find its natural position, and then retorquing the bolts. Also, on the diesel, ensure the engine NVH cover is not fouling on anything (shorting). If it is the rattle that can be caused is amazing. You can simulate this, with the engine idling, by putting hand pressure on various parts of the cover and listening to the change in noise.
Road noise would be the only small complaint that I have with my cars NVH performance, even though I continue to be amazed at how quiet my car is at (at an indicated 77 mph

. There used to be an old saying that if you had a lot of road noise, you had not got enough carpets in the footwell, so extra sound proofing could help, although may be difficult in the pedal box area - and the difficult areas are usually where the noise finds its way in!
You could also try the alternative route of changing your tyres. I would not know what brand to recommend for noise performance, but I have read time and again in the motoring press that a change of tyre make has transformed road noise on various makes of car. Perhaps you could ask your local tyre supplier for an opinion (assuming you have an honest one who will not try to sell you a set of gold plated tyres).
HTH
Andy

Tatts · 29th December 2006, 18:01

Have you seen this?
http://www.noisekiller.co.uk/sound_p...ehicles_04.php

Probably a bit far for you, but they sell diy kits. A weekend project maybe?!

The_Monk · 29th December 2006, 18:06

Quote:

Originally Posted by Tatts

Have you seen this?
http://www.noisekiller.co.uk/sound_p...ehicles_04.php

Probably a bit far for you, but they sell diy kits. A weekend project maybe?!

I had seen them whilst browsing the .org site. I don't think anyone had had it done to give feedback. There was lots of talk about other products that had been used and I only wanted to spend the money once. Although it does look very interesting.

The_Monk · 29th December 2006, 18:11

Quote:

Originally Posted by M47Rman

The basic NVH package, certainly on the original 75 was actually pretty good. A lot of work was done to 'tune' the engine and gearbox mounts to reduce vibration/harshness as much as possible, and also developing the accoustic pack. The twin wall bulkhead makes a huge difference to previous Rover cars, but and it is a BIG but, one of the things we found time and again, was that it only takes ONE plug or cable gland to be missing or incorrectly fitted, and all the hard work is undone. First thing to do is to ensure, as best you can, that all of the routes through the bulkhead, into the car, are sealed as best they can be. Any missing plugs or glands which are partially fitted should be rectified, and this will make a big difference. Also, make sure that the engine is not 'shorting out' on anything. If one of the engine mounts has been fitted incorrectly, with the engine being forced to sit in an artificial position, this will increase engine noise/vibration. This can be fixed by slackening off the engine mounts, and allowing the engine to find its natural position, and then retorquing the bolts. Also, on the diesel, ensure the engine NVH cover is not fouling on anything (shorting). If it is the rattle that can be caused is amazing. You can simulate this, with the engine idling, by putting hand pressure on various parts of the cover and listening to the change in noise.
Road noise would be the only small complaint that I have with my cars NVH performance, even though I continue to be amazed at how quiet my car is at (at an indicated 77 mph

. There used to be an old saying that if you had a lot of road noise, you had not got enough carpets in the footwell, so extra sound proofing could help, although may be difficult in the pedal box area - and the difficult areas are usually where the noise finds its way in!
You could also try the alternative route of changing your tyres. I would not know what brand to recommend for noise performance, but I have read time and again in the motoring press that a change of tyre make has transformed road noise on various makes of car. Perhaps you could ask your local tyre supplier for an opinion (assuming you have an honest one who will not try to sell you a set of gold plated tyres).
HTH
Andy

I will have a look over everything the week before I plan to install. The soundproofting does not come cheap, its one of those things if it works then money well spent! If it don't then.... well! Perhaps if I can find causes of all the possible noise areas I can deal with them in turn!

Alex30013k · 30th December 2006, 13:50

One thing you could do is get a second boot carpet! This reduces a lot of road noise!

I have this, but the 75, with its 16 is silent even up to speeds 70mph +

End of the day what ever you have - you want better!

Christopher · 30th December 2006, 13:57

I supervise a student who is continuing work on an active noise cancellation system for Lotus ... perhaps when it is finished I could persuade them to put it in my 75!

(Me-thinks NOT - so far it requires a half-dozen or so accelerometers or so on the chasis and some mics inside the cabin - road noise is the main target as already explained engine noise is 'easier' to tune out ...)

Alex30013k · 30th December 2006, 13:57

I find that most engine noise comes in where the Air intake is for the Aircon!
In the passengers foot well!

29th December 2006, 11:55	#1
The_Monk I really should get out more....... - Join Date: Nov 2006 Location: - Posts: 2,586 Thanks: 0 Thanked 3 Times in 2 Posts	Soundproofing? I had a quick search and couldn't find anything previous, so sorry if this has been asked before, but has anyone put any soundproofing in their 75's or Zt's? Its mainly road noise at speeds over 50 that begin to irritate. I remember reading about the tyres can cause a lot of noise with them being 18" is this true? Would soundproofing actually reduce this noise on the floor of the car? I know doors, behind the dash should be done as well but the opportunity to do the floor will be available next month. Then hopefully over the next 12months the rest of the car could be done (funds permitting of course ).

29th December 2006, 17:56	#4
M47Rman Avid contributor 2001 Rover 75 saloon 2.5 KV6 Conn SE Automatic Join Date: Nov 2006 Location: Peterborough Posts: 186 Thanks: 0 Thanked 0 Times in 0 Posts	The basic NVH package, certainly on the original 75 was actually pretty good. A lot of work was done to 'tune' the engine and gearbox mounts to reduce vibration/harshness as much as possible, and also developing the accoustic pack. The twin wall bulkhead makes a huge difference to previous Rover cars, but and it is a BIG but, one of the things we found time and again, was that it only takes ONE plug or cable gland to be missing or incorrectly fitted, and all the hard work is undone. First thing to do is to ensure, as best you can, that all of the routes through the bulkhead, into the car, are sealed as best they can be. Any missing plugs or glands which are partially fitted should be rectified, and this will make a big difference. Also, make sure that the engine is not 'shorting out' on anything. If one of the engine mounts has been fitted incorrectly, with the engine being forced to sit in an artificial position, this will increase engine noise/vibration. This can be fixed by slackening off the engine mounts, and allowing the engine to find its natural position, and then retorquing the bolts. Also, on the diesel, ensure the engine NVH cover is not fouling on anything (shorting). If it is the rattle that can be caused is amazing. You can simulate this, with the engine idling, by putting hand pressure on various parts of the cover and listening to the change in noise. Road noise would be the only small complaint that I have with my cars NVH performance, even though I continue to be amazed at how quiet my car is at (at an indicated 77 mph . There used to be an old saying that if you had a lot of road noise, you had not got enough carpets in the footwell, so extra sound proofing could help, although may be difficult in the pedal box area - and the difficult areas are usually where the noise finds its way in! You could also try the alternative route of changing your tyres. I would not know what brand to recommend for noise performance, but I have read time and again in the motoring press that a change of tyre make has transformed road noise on various makes of car. Perhaps you could ask your local tyre supplier for an opinion (assuming you have an honest one who will not try to sell you a set of gold plated tyres). HTH Andy __________________ [SIGPIC][/SIGPIC]

30th December 2006, 13:57	#9
Christopher Owners Club Director Rover 75 V6 Copperleaf Red, MG ZTT 190+ Lagoon & Early MGF Join Date: Oct 2006 Location: Rugby Posts: 9,287 Thanks: 105 Thanked 343 Times in 81 Posts	I supervise a student who is continuing work on an active noise cancellation system for Lotus ... perhaps when it is finished I could persuade them to put it in my 75! (Me-thinks NOT - so far it requires a half-dozen or so accelerometers or so on the chasis and some mics inside the cabin - road noise is the main target as already explained engine noise is 'easier' to tune out ...) __________________ Christopher in banana veritas

29th December 2006, 16:58	#2
Ken Busy doing nothing! . Join Date: Oct 2006 Location: Hampshire Posts: 6,373 Thanks: 33 Thanked 44 Times in 16 Posts	This is a good question and I am looking forward to any answers. I put sound proofing in the engine bay of a 45 and it made the engine noise a lot quieter but then I could hear the rear suspension! :lol: If I did it to my 75 I would have to do the whole thing and not just the bay. To be honest I don't think its needed but the thought has crossed my mind Ken

29th December 2006, 17:54	#3
The_Monk I really should get out more....... - Join Date: Nov 2006 Location: - Posts: 2,586 Thanks: 0 Thanked 3 Times in 2 Posts	I don't actually hear the engine much, not enough to distraction anyway. The road noise is getting rather annoying. I had a search over on the .org site earlier after I posted, and a few different products came up, I didn't realise just how much weight was in them either till reading some of the posts. I dont really have the time to allow products to cure so i'm limited to adhesive mats etc... I can borrow my dads 75 its just finding space to store all the cars insides and I don't have a garage so curing would take ages in this weather!

29th December 2006, 18:01	#5
Tatts This is my second home MG6 TL Join Date: Nov 2006 Location: Tarn Posts: 5,269 Thanks: 2 Thanked 46 Times in 37 Posts	Have you seen this? http://www.noisekiller.co.uk/sound_p...ehicles_04.php Probably a bit far for you, but they sell diy kits. A weekend project maybe?!

30th December 2006, 13:50	#8
Alex30013k Posted a thing or two Rover 75 Saloon 2.0 CDTi Conn Se Join Date: Nov 2006 Location: Ashford Kent Posts: 1,560 Thanks: 17 Thanked 29 Times in 21 Posts	One thing you could do is get a second boot carpet! This reduces a lot of road noise! I have this, but the 75, with its 16 is silent even up to speeds 70mph + End of the day what ever you have - you want better!