How is the soundproof effect of Mass loaded vinyl? not bad!

This video has no post-editing and was shot with pingguo 🍎 12.

Many dudes have uploaded test videos of soundproof materials, but none of them seem to be rigorous and objective.

So I made two wooden frames, one covered Mass loaded vinyl and the other did not. Then I turned on the music and performed a comparison test, you can intuitively feel the effect.

I will appreciate any suggestions and comments from you.

[mysterious_codm]

Should do a test with 2 layer drywall,
50, .75, 1.0 and 2 pound MLV, agasint green glue with 2 layer drywall and see how each performs

[_baller]

And MLV is more for impact sounds too, now try same test with small pieces of drywall and green glue between

[lovemesomepollo]

I'm guessing this is 1/8" thick (one pound per square foot)?

[TANMANTANMAN]

Can i just hang this up in my room lol
Can i just put it on my walls and paint over it acting like its art or do i need to legit cover the whole wall

[KirmesRuf]

From what I understand, mass is what actually soundproofs and absorption (rockwool, etc.) only does so much (Plus helps with echo).

What I don't quite get yet is how mass actually soundproofs. I keep reading about "blocking" sound waves. Or hindering transmission. But doesn't that mean it has to absorb sound in some way? It can't just be reflecting the sound till infinity inside the room.

Same thing with mass loaded vinyl - It's very heavy, so it's good for actual soundproofing. But it's also flexible, unlike drywall. How is it actually blocking sound getting to the outside?

I keep hearing that soundproofing with mass is a different thing than absorption.


Also - When looking at sound proofing drawings, you often see (from the outside to the inside) : A layer of rockwool, then an air gap, another layer of rockwool, another air gap, then 2 drywall layers with a limp layer like green glue inbetween.

Why is it in that order with the drywall part being on the inside of the room. Doesn't that mean it's echoing like crazy and you have to get more absorbers? Why not do it the other way around, with the rockwool layers on the inside and drywall on the outside?

[larrytan]

You have the MLV backwards . WTH? is this?