Mass Loaded Vinyl (MLV) Acoustic Treatments - A Question

MLV is designed to absorb physical resonance (vibrations), not acoustic. It works well when sandwiched between two layers of MDF in a speaker enclosure, for example.

It is being marketed as a sound-proofing solution, a rather high level one at that, for residential and commercial buildings. I am in the construction business but have no experience with this material, cost being the prohibitive factor.

MLV has been used for soundproofing cars for years. It's put between the carpeting and the floor boards in the cabin, in the doors and the trunk. It's very effective at that task; effectiveness as acoustic treatment of a room I can't say.

I decided to take the plunge and get a sheet of 1/8" MLV to see what it was capable of.

From an acoustic perspective it is an inert material,  i.e. it does not resonate at all.
It is somewhat pliable, but it does not like any kind of shape that is rounded in more than one plane i.e. application to a straight pipe is OK as long as there is no bend or curve in the pipe

It does not allow sound waves to pass through it and I believe is reflects very little also.

I have used it to build a couple of different types of acoustic traps and it appears to do a reasonable job of quelling unwanted vibrations

- however that my also be due to in part to the shape of the trap and the other materials used

Structural rigidity is very poor, so it should be glued/fastened in place on a frame or structure. A hot glue gun is a good bonding agent for this material.
You can cut it with a carpet knife, simply scour and bend to open the cut and then finish with one final cut, however, curved cuts can be a little difficult.

Suggested uses:

if you are planning on building an acoustic trap, one suggested use might be to line the inside of the trap with this product. This will act to absorb sound waves inside the trap and reduce vibrations that may be transferred to the outer panels of the trap.

It might also be used for soundproofing a wall, since it is only 1/8" thick - but it is also quite heavy, therefore special glue must be used

The name of the product I use is "Noiseblok" and purchased from..
http://www.acoustiguard.com/ in Toronto (Mississauga), but there are many similar products available on the web from other locations, because it weighs 1 lb/ sq ft - so shipping can be as much as the cost of the product, so try to source locally.

It came in 4' x 6' sheets only and cost $50 CDN/sheet

Bottom Line...

The traps I built have eliminated unwanted reflections that I didn't even realize I had and most of those were around 70 Hz and up. They did result in a significant reduction in what I believe to be standing waves below 70 Hz, but it did not eliminate them completely. However, the taps are significantly smaller than any traps I have seen to date.

That's the scoop on MLV - it's probably more for "the adventurous DIY'er"   :-) 

Regards...