Sound Proofing (SP) Advice Needed

[Elfenstar]

Hi guys, need some advice as this is an area I know little about.

 

My main gripe is road noise from the tyres, and the OEM A349 Aspecs seem to be getting louder (or maybe its because i've been driving the punto more, and it became quieter after I changed the P4's to K415's).

 

Anyway, I'm trying to figure out what way I can most effectively lower the road noise levels. Do note that in their weight reduction scheme for the DE model Mz2's and Demios, Mazda has minimised the SPing done, and if you lift up the spare wheel cover, you'll realise that there is only some minimal spray/paint on sound deadener.

 

In no particular order, this is what I'm planning on doing. Basically I'm targeting a cumulative reduction in tyre noise volume.

1) Change tyres to either the Hankook K415's or Kumho KH17's. Any comments on either tyre in comparison to each other??

2) Get someone to use the spray on/paint on deadener in my wheel arches. Extra coat in the rears as more noise is coming from them. I've read that it helps.

3) Cover the entire boot floor and spare wheel well in sound absorbing materials. Should I do the same for the back of the rear seats and/or the underside of the parcel shelf???

4) Soundproof the firewall on the engine side. Sound absorbing mats at the lower sections extending to a little under the car, and sound reflecting sheets at the upper 1/3rd

 

My assumption with the firewall and boot soundproofing is that both the engine bay and boot act as resonators to increase the road noise.

 

Oh one last thing, When the bass from my music gets too deep, my front door cards seems to vibrate against the inner frame. Should I just use 1.5/2mm insulation foam to line the frame or should I just SP my front doors??? I've heard that you get tighter bass with the latter.

[Leepee]

In no particular order, this is what I'm planning on doing. Basically I'm targeting a cumulative reduction in tyre noise volume.

1) Change tyres to either the Hankook K415's or Kumho KH17's. Any comments on either tyre in comparison to each other??

> I would not as all tyres are more or less noisy after some time.

 

2) Get someone to use the spray on/paint on deadener in my wheel arches. Extra coat in the rears as more noise is coming from them. I've read that it helps.

> I would do the sound deadener like tuff cost under chassie and wheel arch. I think extra cost is not necessary.

 

3) Cover the entire boot floor and spare wheel ell in sound absorbing materials. Should I do the same for the back of the rear seats and/or the underside of the parcel shelf???

> Yes, it would help the most. There are industrial 3 layers density foam that will be very effective against sound and vibration transmission. Remember the normal rubber mat(dyna-mat) only reduce resonance/vibration on the metal floor plate. You will need a softer and thicker sponge layer, to effective absorb the sound sound energy.

 

4) Soundproof the firewall on the engine side. Sound absorbing mats at the lower sections extending to a little under the car, and sound reflecting sheets at the upper 1/3rd

> Not easy to do, new and clean car still ok. If old and dirty car, it will be messy and hard to paste. Well, if you got the time and $, can do it too.

 

My assumption with the firewall and boot soundproofing is that both the engine bay and boot act as resonators to increase the road noise.

> Yes, but don't over do it. Just a few strategically placed dynamat will dampen the metal vibration. But you still need a physical softer and thicker sponge like layer to reduce the sound transmission from the firewall and boot area.

 

 

Oh one last thing, When the bass from my music gets too deep, my front door cards seems to vibrate against the inner frame. Should I just use 1.5/2mm insulation foam to line the frame or should I just SP my front doors??? I've heard that you get tighter bass with the latter.

> Yes SP the front door as well. The door card is tricky, you have to isolate the contact point that is causing the vibration and then apply soft density foam at those contact points to reduce vibration. If your door card is 'light', maybe placing some dynamat at those 'hollow' sounding area will help.

 

 

 

 

 

 

 

 

 

[Leepee]

Multi-layer type of sound proof for the floor and boot area.

 

http://www.soundprooffoam.com/ultra-barrier-plus.html

[Leepee]

These are more efective than just dynamat alone..

It reduced vibration and air borne vibration!

 

http://www.silentsource.com/barriers-whispermat1and2.html

[Ngck]

My humble experience....

 

 

1) Change tyres to either the Hankook K415's or Kumho KH17's. Any comments on either tyre in comparison to each other??

This on no ides.. never use kumho before.... but anyway whatever tyre you use, once high mileage and rubber harden will be noisy.

so either you live with it or change more regularly

 

 

2) Get someone to use the spray on/paint on deadener in my wheel arches. Extra coat in the rears as more noise is coming from them. I've read that it helps.

 

 

No use spraying stuff on rear wheel arcs as those areas already quite enclose from the cabin (Unlike front arc.)...

If want to do it, apply sound proof materials on rear seat portion(Which covers the rear wheel arc).

 

might as well sound proof the entire cabin (like i did)... especially the top. When raining, you will hear the difference...

 

 

 

3) Cover the entire boot floor and spare wheel well in sound absorbing materials. Should I do the same for the back of the rear seats and/or the underside of the parcel shelf???

Same as question 2

 

 

 

4) Soundproof the firewall on the engine side. Sound absorbing mats at the lower sections extending to a little under the car, and sound reflecting sheets at the upper 1/3rd

 

no experience on firewall as its time consuming and expensive... alot of work to be done.

 

 

anyway, if you intend to do it, just do a proper one... here abit there abit you cannot feel the effect.

 

For me, i did my floor plan. 4 doors, top, boot, front arc (cause its only plastics cover for front arc for most cars unlike the rear which is metal with coating already)

 

you might also want to reduce wind noise by covering whatever gaps the the sound is coming from. Normally from windows portion from hardening rubber.

[Elfenstar]

Thanks for the replies thus far

 

I do miss working on a car, so I'm planning on doing most of this myself. Anything to do with spraying or painting on i will outsource though as I doubt anyone can find someone worse than me in applicating liquids or gels

 

There was a drastic sound reduction from changing the tyres on the punto to the K415. Tyre noise went from being as loud as the Demio to near silent at slower speeds on a smooth surface. The KH17's are supposed to match if not better them so I'm contemplating between the two (personal experience vs tests from others). I do plan on changing my tyres every 1 to 1.5yrs though, so if there are any other recommendations with above average grip both in wet and dry like these two pls feel free to recommend them. Wear rate doesnt matter.

 

The noise seems to be coming from behind which is the norm in a hatch (even if the source is in the front) which is why I plan on only using sound absorbing materials on the boot floor and spare wheel well. However after monkeying around with the rear seats down and someone else driving, I'm very sure that most of the tyre noise is from the rear. So I shouldn't use the spray on deadener in the rear wheel arches but use SPing on the inside of the wheel well? What if I do both? And what type of sound deadening material should I use for that section?

 

The front sounds fine right? Any comments on using different SP material types on the firewall???

 

I'm leaving the roof as my target is tyre noise, and I'm leaving the floorplan as I'm getting some floormats that deaden sound made-up. I don't actually mind the tyre noise, its the volume that I have an issue with

[Picanto]

what is your budget like?

[Leclair]

install better ICE, on the volume louder , play your favorite music and you wont need to do all these stuff ( which btw may or may not effective.)

 

But if your concern is the tyre than just change the tyres to those known to be quiet type.

 

REgarding the front door sp, the sq ( sound quality) will be better as there will be less vibration of your 2 front speakers on the doors, thus providing better Sq.

 

 

[Picanto]

  On 5/1/2012 at 2:45 AM, Leclair said:

install better ICE, on the volume louder , play your favorite music and you wont need to do all these stuff ( which btw may or may not effective.)

 

But if your concern is the tyre than just change the tyres to those known to be quiet type.

 

REgarding the front door sp, the sq ( sound quality) will be better as there will be less vibration of your 2 front speakers on the doors, thus providing better Sq.

 

SP is an important part of ICE

[Elfenstar]

  On 5/1/2012 at 12:53 AM, Picanto said:

what is your budget like?

 

About 2.5 years too late bro Change car liao.

[SimonTan]

So is the new car better in terms or quiet interior?

No need aftermarket SP?