Ringing doors

[azopelnut]

I know that there are a number of threads discussing sound deadening materials but I have a specific problem that I could not find the answer to.
My Sportwagon doors have a very annoying resonance (ring) when shut.
I am not into adding much weight to the car so sound deadening material placement is import.
For door deadening which is the best surface to either spray or attach material to:
1) The inner surface of the outer door skin
2) The outer surface of the inner door skin
3) The inner surface of the inner door skin (where the door panel touches)

In most car stereo shops it seems like they do 1 and 3 but that seems like a lot of weight.

[opelwasp]

Paul if your goal is to reduce the doors resonant frequency then sound deadening the "drum" portion of the door is fine, ie. the door skin. Stereo shops do both because of said door ring and to prevent any resonance in the inner panel due to the speaker itself.

[OpelJim]

Originally Posted by opelwasp Paul if your goal is to reduce the doors resonant frequency then sound deadening the "drum" portion of the door is fine, ie. the door skin. Stereo shops do both because of said door ring and to prevent any resonance in the inner panel due to the speaker itself.

Scary quote

[Aardvaark]

I thought this may have come up before. I search but didn't find the fix posted. Maybe I missed it.
The ringing heard on many Opels when the doors are closed is very easily
cured, but I guess the fix has been lost to time.
I just cured this again this morning on my "new" Manta.
It's the two small vertical extension springs on the lock mechanism vibrating.
I just wedge a 1" long piece of 1/8" dia vacuum hose between them and
the doors sound like bank vault doors as the should.
You have to remove the inside panel and pull back the plastic sheet
near the lock and large access hole to reach in to the spring.

-Mark

[David McCollam]

Could you send a photo or drawing? I can't envision the springs to which you refer on the Manta lock mechanism.

Thanks,

Dave

[Aardvaark]

Glad to David.
The photo is from the '74 service manual pp 2C-12.
The back of the lock/latch asm isn't shown but my
sketch shows what you will see if you access it.
Any other questions, ask away.
Regards,
Mark