Sound deadening disappointment

[rohrt]

I know some of you swear by the sound deadening but I have to say I really can’t tell much of a difference. I used a high end DynoMatt equivalent and covered the whole interior. Drove the car with no interior, drove the car with just the sound deadening and drove again once the carpet was in.

In all fairness this is a convertible with very loud strait through mufflers, so if it helped with road noise I would not be able to detect it.

[jocko124]

Dynamat only takes care of vibration and does not block sound. True sound deadening usually entails multiple layers of various materials.

[wmhjr]

Having driven my '66 GTO Convertible a bit by now, my experience is far different. 2nd Skin Damplifier Pro and Luxury Liner. 600hp motor, loud exhaust. Yeah, the exhaust is still loud, but the car itself feels "solid" and is much more pleasant. Even notice the difference just shutting doors, etc.

[rohrt]

Having driven my '66 GTO Convertible a bit by now, my experience is far different. 2nd Skin Damplifier Pro and Luxury Liner. 600hp motor, loud exhaust. Yeah, the exhaust is still loud, but the car itself feels "solid" and is much more pleasant. Even notice the difference just shutting doors, etc.

I would knock on the panels with each sheet I installed. To me the difference was slight.

[wmhjr]

Interesting. The difference to me was the difference between a kettle drum and a solid object. Did you put the stuff everywhere? I put damplifier Pro in the doors, quarters, wheel houses, trunk (everywhere) firewall, floors. Covered everything pretty much. Then Luxury Liner Pro on Firewall, floors and trunk. I now have zero vibration sound or "echo" kind of sound. Close a door and it's SOLID. Night and day difference.

[silver69camaro]

I would think there would be less of an improvement in a convertable, where most of the noise is carried in through the top, instead of the bottom.

[fordsbyjay]

I know some of you swear by the sound deadening but I have to say I really can’t tell much of a difference. I used a high end DynoMatt equivalent and covered the whole interior. Drove the car with no interior, drove the car with just the sound deadening and drove again once the carpet was in.

In all fairness this is a convertible with very loud strait through mufflers, so if it helped with road noise I would not be able to detect it.

What is a "high end Dynomat equivalent? I am no expert but from what I have read here there is a big difference between brands.

[wmhjr]

I would think there would be less of an improvement in a convertable, where most of the noise is carried in through the top, instead of the bottom.

You're somewhat right. If you're trying to eliminate exhaust noise from a relatively loud exhaust, it's gonna be tough. But road noise, vibration, and "echo"? Big difference there. I mainly hear my exhaust (which is a bit loud) but not road noise or rattles. You'll never make a vert as quiet as a coupe. But it's worth the effort to try.

[rohrt]

You're somewhat right. If you're trying to eliminate exhaust noise from a relatively loud exhaust, it's gonna be tough. But road noise, vibration, and "echo"? Big difference there. I mainly hear my exhaust (which is a bit loud) but not road noise or rattles. You'll never make a vert as quiet as a coupe. But it's worth the effort to try.

My exhaust dron is from 2200-2800 and is obnoxiously loud. I post this to only serve as a warning to others that if you expect the exhaust noise to quiet down, it won't. Road noise or vibration rattles I believe, just can't tell at this point.

I'm getting old so bought a set DynoMax mufflers that I plan to throw on the car. I just won't have a reference for comparison like I did before.

[wmhjr]

OK, so it's really not overall sound deadening performance you're unhappy with, but the ability to remove exhaust drone.....

Different story. I'm not sure anything other than ear plugs can help if you have really persistent exhaust drone. There is also a difference between trying to deal with "exhaust noise" and "exhaust drone". Very different animals.

[aronhk_md]

Yes, there isnt a thing thats going to get rid of the exhaust drone on my Spin Tech mufflers between 2100 and 2600 rpm. At those rpms they resonate. Switching to a different muffler can help. I'm going with a set of Goerlich Xcelerator x123's on mine....which is moving up from a 14" to an 18" muffler, has been shown to reduce about 10 db from what I have and NO resonance from what I've been told. All in a muffler thats been tested to flow 99% of what free pipes flow. Hope its all true...lol

[Second Skin Rep]

When it comes to noise reduction in automobiles, there are 2 tyeps of sound deadeners that are commonly used:

1. Constraint layer Dampers - Foil backed mats with elastomeric adhesive similar to the Dynamat Extreme you are used to. These vibration dampers reduce structure borne noise, (vibrations) and to a degree, reduce some heat and make the car feel a bit more solid. This is always the foundation layer of any automotive insulation project.

2. Noise Barriers- these are usually mass loaded vinyl or lead sheeting laminated to a foam decoupler. These go on top of the vibration dmaper to block the transmission of airborne sound waves.

Many company advertise that their vibration dampers will lower road noise and exhaust drone by 20 db or more. This is crap.
VIbration dampers reduce vibrations. That is about it.

The barrier does the grunt of the work on airborne noise so it should be the hero. Not the damper. Dampers however are very improteant and will, on theri own make a very noticable impact on noise levels and comfort levels.


Dynamat Extrme is a good product for what it is, but it is pretty expensive
There are lots of comparable products out there tha cost less, and some, that are much better than Dynamat Extreme, and still cost less.

I am not here to spam the board, so if anyone has any specific questions about our products, go ahead and ask.

Hope that helps!

ANT

[CarlC]

Where does the exhaust exit? Full tailpipes that exit straight back will help. Big engines, big cams, big exhaust tubing, ineffective small mufflers, and turndowns will always be loud no matter what other barriers are put in place.

Using the largest possible effective muffler is important. I've had good luck with Dynomax Super Turbos on several builds. Dynomax also makes a larger version 3" in/out that works well.

[Chevy Kid]

X2 on the DynoMax Super Turbo's!

Tim