Mass Loaded Vinyl (MLV) Acoustic Treatments - A Question

Hi all,

I have nothing that compares with bugredmachine’s extensive "ground-up" installation, but went through a challenging time damping the excessive low/mid-bass frequencies in my 15’ X 24’ X 9’ room.

I read a ton of stuff by Jon Risch on another forum and built floor-to-ceiling SEALED corner bass traps using 2" thick by 24" wide dense fiberglass panels (not the loose pink in-a-roll kind you buy at home-improvement stores) found at a builder supply warehouse and common 1/2" thick 4" wide plywood planks to build the frame around the fiberglass. Covered them with an attractive acoustically transparent fabric to match the room and to keep fiberglass particles from entering the air in my listening room. I used a thick, yet pliable rubber garage-door gasket material to seal the traps into the front corners of the room (behind the speakers) all the way around the frame.

These worked wonders to eliminate the exaggerated mid/low bass in my room without overdamping the overall sound. Pics can be seen on my system page.

I also built smaller 2" thick 24" X 48" panels for side-wall reflections using the same materials and construction technique (but unsealed) that are place at the midpoint between my speakers’ front baffle and my listening position. Audible improvement in imaging and soundstaging.

I recall that it cost me around $500 total plus a few days of dedicated construction/installation time.

I hope this is helpful.

Best to you all,
Dave

I just finished my new room, just posted in All Out Assault, and I incorporated MLV on the ceiling of a 16 x 20 room. It cost me $500 for the materials. I have done many rooms and this is the first with MLV. Was it worth it? Overall it does help (living room is directly above) but it kicked our butts getting it up. I used a drywall lift and still had to cut the 15 foot rolls in half to have a chance in cranking it up to the ceiling. I had to screw it in and then go back and add some nails. We taped all the seams as well.

The heating ducts will ruin the effects of MLV if you don't treat them properly. DOn't ignore them, they carry everything up and away.

My ceiling is 16 OC joists with rockwool in it, MLV, hat channel, 2 layers of drywall with greenglue, then diffusion and absorption to taste. I'll try to add some of the construction pics here but over on AudioCircle my complete room build is documented.

@shahzada123 

Any chance on you posting those pics? I'm starting in on room treatment and you sound like you know what you're doing..

I rarely post here but seeing that this is right down my alley, I thought I'll chime in.
I've been in the Industrial Acoustics field for almost 20 years and in my experience the best product for low frequency attenuation is Rockwool.
Fiberwool would be the next one, foam being the least effective among these three but does work once the density is suitably high.

I've treated my room accordingly and the sound is absolutely fantastic.
I will add some pictures of the back wall, to my virtual system, to try and show what I'm talking about.
Wooden diffusers have also been used to a great effect.

I don't think MLV would help in taming low frequencies

I'm not an engineer, just someone who's in the business of manufacturing Sound Attenuated Enclosures.

Apologies if I came across as condescending, just that I'm not used to writing here, prefer reading.   
-S

Vinyl based products and rubber and so on, do squash vibrations, but aren't appropriate for a superior sonic solution regarding isolation in an audiophile listening environment

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...

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.

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 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.

Hi, I'm not familiar with the (MLV) treatments. Upon the very nature of (vinyl), to me, it suggests more of a reflection treatment? Is this your experience? Other than (proper placement) of speakers, in my room/experience, I found a combination of diffusion/absorbtion to be the ticket. My smaller room, (8.6" x13.8"x8'). I get a substantial difference in sound upon very small increments in placement of these treatments.

I'm a single guy so, "limiting visibility" isn't at all necessary. This may be the limiting factor in achieving the best sound for you?

Good luck!