Sound Proofing..

[Mavvy]

You fellows very into acoustics...

 

I can only do that when at home.. heh... my ride to work only 8 mins.. not worth doing alot..

[Michel]

Mine's a 20 minutes' ride to work. But, in my case, it can be quite noisy on certain stretches of the road.

[Michel]

Will let you know if i find any.

[Mavvy]

I see... 20 minutes still can hear couple of songs.. the most for me is two..

[Michel]

[Mully]

$80?

 

Hmm top it up a little I'll buy those active noise cancellation ear-phones from Sony.

 

I did research and some work on active near real-time, and predictive noise cancellation technologies last time... Really quite interested in noise cancellation...

 

NO, Cool, NOT Sound proofing... I not interested in sound proofing... I HATE BITUMEN!

 

Understand that quite a number of upmarket brands in US offer active noise cancellation/management systems in built into their factory fitted ICE.

 

Are there any after narket ICE system that has active noise management?

 

Thanks for any leads.

[Apollo]

to DIY or whatever,

 

step 1 is to quantify the noise. ie get a soundmeter and measure the noise level at various location within the car, when it is parked, when moving, when adjacent larger vehicle passes.

 

location to measure include floor pan, door side, front screen, side window.

typical problem areas are wheel arch, floor pan and door (driver side).

 

step 2.

A. understand noise.

ambient noise level in an office is ard 40dB. ur HDB flat may be 50-60dB. industrial depends 70-100dB. a mitsubishi aircon ard 41dB. road noise ard 60dB.

 

if car A which has engine noise of 50dB drive pass u, then follow by bus A with noise of 70dB pass u, bus A will mask the noise by car A.

if bus B has same noise level as bus A and both drive pass u, the noise level is 70+3dB.

if bus C has same noise level as A and B, then the noise level is 70+3+3 dB, simple rule.

 

noise deteriorate by distance and thru material exponientially due to the power law.

 

internal factor

when not moving or speed below 60kmh, it is engine noise.

when moving fast, it is wind noise and tyre noise.

 

external factor

adjacent vehicle.

 

step 3.

B. understand construction.

 

check wat is below ur carpet. any undercarpet layer?

check the engine bay, any bonnet insulator?

check the doors / front & rear fenders by lightly tapping with ur knuckles.

check the firewall internally and at the engine bay area, any material to insulate?

if ur glass only 3mm thick, noise reduction is smthg like 10-12 dB only. this is imprt as i exprain below.

 

step 4.

C. understand location.

 

the most impt location is the driver at ear level. this is where u pick up the problem and makes the decision. even though i hv pointed out to quantify noise at various location. do understand, u can insulate anywhere except the glass. and becos ur ears r at this level, any improvement u made (to b quantified again after doing SP), u will not improve beyond this level. ie u r basically screwed by the glass. so if u hv a measurement of say 70dB when a bus drove pass ur side glass, that's it. if nothing drove pass, mebbe u hv 60dB due to engine noise.

 

so wat can b done? basically, u mask the noise fr the engine/ tyre at the floorpan/door to below the 60dB mark. it is not economical or technically possible to mask the noise down to 40dB becos of inherent problem of the glass. (note: check out thickness of BMW and lexus and u can understand why). so why thinner glass used by manufacturers? cut load + cut cost + better FC.

 

step 5.

D. Choosing the right material. never overinsulate.

 

some material are solid in nature,they act as physical barrier to impede noise. eg dynamat, silent, etc

others which r porous seek to absorb noise. such as cinema walls. eg insulflex neoprene open cells. carpet underlayer.

 

an imprt lesson here is sound imaging, etc tat u may hv learnt in ICE. do remember, the most dangerous thing is to over insulate. the reason for this is becos it is hardly possible to prevent noise entering ur car. but when the noise does enter, u will want to absorb it away as well as leaking it out away from you. otherwise, the noise will reverberate within the ride making it even more uncomfortable.

 

step 6. validate ur noise reduction.

 

if u hv done the quantifiable method using soundmeter, it is possible to generate noise externally within a workshop and to test out what u hv installed.

[Honda2]

What is the difference betw Dynmat and Accumat. Which is better.

[Prosumer]

Wow! Apollo, thanks for taking the time & effort to share these....

 

The part on measuring it b4 and after is really key.

 

I was quoted $250 to sound proof the front doors. Didn't ask what materials, etc. as I'm new to these. Having some meaurement will determine if the money is well spent.

[Apollo]

dunno leh...

 

tat one is my friend, the kachang puteh man tell me one. haven try yet...

 

u mean really can work arh? oh.....

[Baka]

I was quoted $300 for 4 doors and wheel arc for soundproofing.. now considering

 

The workshop guy told me another good thing abt soundproofing is that it will toughen the metal. When kena knocked in accidents, it will not get dented so easily. Is he bull sh|tting?

[Apollo]

of cos he bull shitting lor.. if kena accident. will need to replace entire door, and re-SP again.

 

$300 depends on wat he use, where he use. if he gg to give u single layer on doors and wheel arch, might as well dun do. i count is 1.5 pc per door. total mebbe only 5 pc, ard $50 per pc. roughly i suspect using chirper material not dynamat.

 

normal door, need slightly more then 2 pc, ard 2.5 pc for 2 layer 1 inside 1 outside.

[Baka]

his workshop a bit run down... although business looks ok for them when I visited, but dun feel good about their workmanship and quality... you got good lobang of workshop can PM me? thanks!

[Apollo]

really is up to u. at the price is unlikely to be dynamat. best u ask him explain more what he is doing, how many layers, etc.

 

i suggest u do it if it is within ur means if not do double layer at wheel arch 1st n not overstretch since any ICE stuff is always poisonous. door can do when u upgrade the speakers becos need to hide the passive crossover. u may also wanna consider snake lights for the door as well. so doing the doors at one go is better.

 

however, remember... all door panels must be stored properly one side when removed. if u hv masking tape, tape the door sill so paint wun b damaged. tape + plastic sheet the panel also. i suspect he will just make use of used canvas and if u hv chirp plastic trimming, they may b damaged unduly.

[Baka]

I intend to do double layers at 4 doors and single layer at arch. I am going to fix the component speakers this month end, so thinking of doing SP together while he fix the speakers.

 

wat is snake lights btw?

[Apollo]

snake lights LED normally pple now fix for doors. yes, fix SP layer with door otherwise problem. will look ugly to remove the SP and repaste.

[Baka]

I have done up the ICE and soundproofing for the doors, but could not have time to do SP for the wheel arch as I stayed with them till 3am. They did not detach the doors like what you said.. they just stick the SP layers straight to the opened doors.

 

Will next install the snake lights as I think they are quite cool looking. The vendor quote me $50 for snake lights per door, saying the products are good and durable ones... you think is good price?

[Apollo]

$50 try asking other shops. so i was quite right only 1 layer.. how the hell it took them so long to do it? only 1 worker for ur ride doing everything?