in-car noise

[thinkfloyd14]

I think I may have a problem. I've been having trouble sleeping sometimes because my ears are ringing. It may be an early sign of tinnitus... I'm 23 now... can it be because of the car I drive?

I have a 76 911 coupe with a 3.0 motor M and K exhaust 2 in 1 out.

Carpet but no sound deadening underneath that. I just downloaded a sound decibel measuring app on my iPhone and measured around 86-88 db while driving on the freeway in 5th gear. Another 7-10 db if i have the music on.

This has got to be too loud... what are your best suggestions?

-sammy

[ivangene]

dont look now but that damn rock N roll is most likely whats causing you to go deaf!!!




kidding!!!!

[DRACO A5OG]

I have to say after installing the "Ultimate Sound Pad" I could actually have a conversation with my lady, very quiet now and my ears don't hum after a long hard drive.

Much more enjoyable then before :-)

Jim

23? I remember when I was 23, wow so long ago , real loud music at clubs, my ears use to ring all the time :-P

[tobluforu]

I had to get rid of my MK 2 out because it was killing my ears, but I'm pretty sure it was louder then your 1 out. It may not be the DB that is killing your ears, but the drone, pull exhaust and see if that helps.

[thinkfloyd14]

How about dynamat?

[JP911]

It may be boring, but there's nothing like a stock 2-in, 1-out. You won't lose performance, it just sounds like a Porsche should, and you'll save your ears. Loud Porsche engines are cool and all, but it gets old in real use...especially daily use.

[DaddyGlenn]

FYI - extreme caffine intake can cause a ringing in the ears that will be with you forever.....

[KNS]

If you're only 23 do what you can now to preserve your hearing, you'll thank yourself when your 43 or 63. If that means a quieter muffler and a little extra sound insulation - do it.

Remember, from this point on your hearing will never get any better.

[Packet82]

Go back to the stock exhaust, consider replacing the sound pad in the engine compartment, or putting some sound deadening under the carpet.

I just replaced my carpets. While I was in there I ripped out all the stock 30 year old sound deadening and replaced it with more modern stuff. It's made a pretty decent difference in sound levels in the car. It's not a mercedes and isn't going to be dead quiet, nor should it. However, I can actually hold a conversation with someone while driving now.

[KNS]

If you're approaching 100 dB you are damaging your hearing. Insulation under the carpet will muffle road noise - good but what you want is to quiet down the noise behind you as well. Get a stock 1 out muffler and see if you can add some extra insulation behind your parcel shelf. Mass Loaded Vinyl (MLV) will help.

I should also add: I just installed new, stock motor mounts, not the OE ones but Porsche items. I had installed German OE mounts but the were sagging in six months. When I replaced those with stock, factory mounts I noticed a nice little drop in noise on the highway!

I believe the Porsche mounts are superior to the cheaper OE ones.

[DaddyGlenn]

Damn those un muffled early 80's RX-7 race cars..... Wish I wore ear plugs back then. But then again, I was only 20-something...

Add sound deadening material. You will also find the reduced noise will reduce how tired you get on long drives. Excessive noise sucks the energy out of you, too.

[steve911T]

Get some earplugs from Lowe's or where ever and that will make it reasonable. You will still hear it but will cut out some of the decibels.

[dshepp806]

I'd use a lab grade device to measure it (dB levels).

As to the ears: I'd get in to see a Doc about that,..even go ahead and have a hearing test done. Hell,..it could be your blood pressure or something FAR removed from the car.... For your own health, DO rule out any medical condition (ears and everything else)

I can't even begin to tell you how careful you must be is protecting your hearing, starting at an early age. Music (engineering) has always been something dear to me.........these ears are different from 25 years ago...I go in annually to have my hearing curves plotted...having mixed some LOUD bands over many years, I can tell you that it comes with a price (at almost 55 years old) of "curve alteration...certainly has influenced my studio/production mixdowns.....Many years ago we started using tuned ear plugs for sound reduction when working FOH (especially in LARGE venues),..studio is another matter entirely...

As to the car,..yeap,..deadened it to death (if you aren't necc'y a weight freak), as your speakers will be better "presented"...

I wouldn't know anything about the various exhaust mods (other than what I read) on a personal note.....only a stock, '89 setup........never measured it,..but I consider it quite sweet, especially at high revs.....!!!!!!!!

BEST!

Doyle

[Jerome74911S]

I have a Dansk Sport 2 in 1 out muffler. I can't even hear it because of the gear whine and fan screaming noise that conquers all else. I have to wear ear plugs to avoid going deaf.

Is a silent transaxle a fantasy? And, what about the fan?

[teenerted1]

ear plugs.

[timmy2]

You guys have motivated me to lay down some sound mat in the interior of my car. I have a bulk roll I bought for my 442 restoration, but I'm going to take a yard or so and apply it to my SC. I'm in an industrial setting at work and have no hearing degredation after 25 years. Don't need to start now!

[nineball]

to really "block" noise it is a 3 step solution.

1. apply a cld (constrained layer damper). this is what dynamat xtreme and second skin damplifier / damplifier pro is: a butyl-based rubber with a layer of adhesive on one side and a layer of aluminum on the other. the adhesive side is applied directly to the metal panel, the butyl converts vibrations into low level heat which is then dissipated by the aluminum. you only need 25-40% coverage on large flat panels for this to be 100% effective. there is no need to do 100% coverage as you are just wasting time, effort and product (money).

2. apply a ccf (closed-cell foam) decoupler. most people use ensolite, or a similar closed-cell foam product. thickness varies but a minimum is 1/8", up to 1/4" will work as well. this acts as a separator between the cld and mlv and also serves to block some of the spectrum of sound. some come with adhesive applied already but if not something like 3m super90 spray adhesive will do the trick. this needs 100% coverage.

3. the last step, and the one that actually blocks (or repels) the sound is mlv or mass loaded vinyl. the optimal solution for most car applications should weight approx. 1lb/foot, and this needs 100% coverage to be effective. you also need to seal up any seams as noise (like water) will find the path of least resistance. overlapping the mlv and sealing it with a contact cement-type glue is the best method but you can also use a heavy duty tape.

if you have any questions feel free to ask and i'll help in any way i can (including pics of my install).

ps> applying steps 1 and 2 to the inside of the outer skin and inside of the inner skin of the doors will greatly improve your audio output as well. the cld helps with vibrations caused by the speaker and the ccf absorbs the backwaves of the speaker.

[fanaudical]

85dB continuous noise is the threshold for mandatory hearing protection in an industrial setting. I don't see earplugs as a practical solution for a street vehicle. I think sound deadening is your answer.

[hcoles]

Originally Posted by jp911

it may be boring, but there's nothing like a stock 2-in, 1-out. You won't lose performance, it just sounds like a porsche should, and you'll save your ears. Loud porsche engines are cool and all, but it gets old in real use...especially daily use.

+1

[wwest]

Originally Posted by nineball

to really "block" noise it is a 3 step solution.

1. apply a cld (constrained layer damper). this is what dynamat xtreme and second skin damplifier / damplifier pro is: a butyl-based rubber with a layer of adhesive on one side and a layer of aluminum on the other. the adhesive side is applied directly to the metal panel, the butyl converts vibrations into low level heat which is then dissipated by the aluminum. you only need 25-40% coverage on large flat panels for this to be 100% effective. there is no need to do 100% coverage as you are just wasting time, effort and product (money).

2. apply a ccf (closed-cell foam) decoupler. most people use ensolite, or a similar closed-cell foam product. thickness varies but a minimum is 1/8", up to 1/4" will work as well. this acts as a separator between the cld and mlv and also serves to block some of the spectrum of sound. some come with adhesive applied already but if not something like 3m super90 spray adhesive will do the trick. this needs 100% coverage.

3. the last step, and the one that actually blocks (or repels) the sound is mlv or mass loaded vinyl. the optimal solution for most car applications should weight approx. 1lb/foot, and this needs 100% coverage to be effective. you also need to seal up any seams as noise (like water) will find the path of least resistance. overlapping the mlv and sealing it with a contact cement-type glue is the best method but you can also use a heavy duty tape.

if you have any questions feel free to ask and i'll help in any way i can (including pics of my install).

ps> applying steps 1 and 2 to the inside of the outer skin and inside of the inner skin of the doors will greatly improve your audio output as well. the cld helps with vibrations caused by the speaker and the ccf absorbs the backwaves of the speaker.

4. Pressure wash/clean the wheelwells and discharge a full spray can of aftermarket undercoating into each.