Sound Absorbing Acoustic Paint Experiences

[BarfanyShart]

So I moved into this new house that is much bigger than my old house, with high ceilings, and an open concept thing. The echo/reverb is really bad in the house, and even after we are done accumulating furniture and curtains and all of that, I think it will still be a problem. We have to paint the interior of the house at some point soon anyway, so I am thinking that acoustic paint may help. My expectations are realistic, but if the cumulative effect is a 25% reduction in echo and reverb in the main areas of the house, that will be "worth it" for my goals.

Anyone have any experience with this stuff? Suggestions, brands, application methods, opinions?

 

[AGCurry]

I don't see how it could possibly help you.

Acoustic paint is more commonly known as "soundproofing" paint, and it works for soundproofing by drying with voids embedded in the paint coat. Those voids provide acoustic insulation, like foam.

Echoes and reverberation result from sound waves bouncing around in a room. The treatment for those problems is not to cover the walls with some material, but to interrupt the sound waves within the room, using gobos, partitions, and traps. The furniture will help to some degree.

 

[silky smoove]

Here's a useful thread on the subject. Pay special attention to posts by Rod Gervais who's an expert in this field: Invalid Link Removed

As a means of an acoustic treatment it's the wrong tool for the job.

 

[Basslice]

I don't know anything about "Acoustic Paint" in particular, but I am an expert in polymers and coatings. I can't imagine a scenario where paint can change the acoustics of a room. Maybe knock down vibrational noises if something is vibrating against it. It would have to be about a half meter thick to really affect acoustics!

Like I said, maybe I am missing something here.

 

[Basslice]

I know in naval applications (ship and submarine hulls, for example), there are acoustic properties and sound frequency reflection properties that can be influenced by coatings - read SONAR. But that is quite different than aural hearing frequencies of LOUD music in a studio.

 

[AGCurry]

I don't know anything about "Acoustic Paint" in particular, but I am an expert in polymers and coatings. I can't imagine a scenario where paint can change the acoustics of a room. Maybe knock down vibrational noises if something is vibrating against it. It would have to be about a half meter thick to really affect acoustics!

Like I said, maybe I am missing something here.

Well, a "popcorn ceiling" can cut down on high-frequency reflections. A glass or marble wall will reflect more high frequencies than a fabric-covered wall. But lower frequencies are controlled by interrupting standing waves.

 

[silky smoove]

I can't imagine a scenario where paint can change the acoustics of a room.

You would be right, except for a tiny bit of a high frequency reflections which are almost never the actual problem. The paint in question is supposed to be an isolation measure, not an acoustic treatment. In other words, it is meant to limit transmission of sound from one space to another, not the reflection characteristics within a space.

 

[Basslice]

You would be right, except for a tiny bit of a high frequency reflections which are almost never the actual problem. The paint in question is supposed to be an isolation measure, not an acoustic treatment. In other words, it is meant to limit transmission of sound from one space to another, not the reflection characteristics within a space.

I see. Then that is even worse. A case could be made for reflection of very high frequencies, but transmission of a film will depend much more on the substrate than the film. Unless said film is thick and of the right density. It is physics. Magic not involved.

 

[Basslice]

I mean lets look at the problem from a mechanical point of view. You have sound waves moving air towards a surface. There is a certain energy associated with that sound wave. Some gets reflected, but most gets absorbed. What happens to the energy upon absorption? It either causes the surface to resonate and -re-transmit, or it gets dissipated as heat (actually not an either/or, both happen). Thus if you are trying to keep sound from leaking, you have a big problem that is solved by having enough stiff mass that reflects or dissipates (traps) the energy.

So it is no mystery that large concrete walls work a lot better than wood framed walls with sheet rock. There are parameters for materials that have interesting interactions with energy at the Hz to KHz spectrum. There are also a lot of neat tricks that one can do by using phase cancellation and other tricks.

But a paint? Not gonna cut it. Unless you are talking about very specific reflections, the substrate (wall, ceiling or floor) is gonna catch most of that energy.

Now lets say you have some highly unusually dense and stiff material - Unobtanium - then you are in business. I would look at the bottom of the periodic table. You might need a cyclotron to make some of those elements and alloys. YMMV

 

[MynameisMe]

You might try just breaking up the wall with pictures or some acoustical panels.
You can buy them online In many shapes.
I have no affiliation with this company but with these look reasonable in price.
I have installed many.Professional Grade Acoustic Panels, Sound Absorbing Panels | Acoustimac.com
Piece of cake.

 

[BarfanyShart]

Thank you for the input, and I am also dubious about the properties of this paint. I also know how to do real sound treatment with panels and furnishings and whatnot. I really wanted to know if anybody has actually used one of these paint products, and has any first-hand experience with the effects.

 

[silky smoove]

I really wanted to know if anybody has actually used one of these paint products, and has any first-hand experience with the effects.

I suspect you're not going to find many folks who have outside of the companies that make them. It doesn't seem terribly effective, is relatively expensive when comparing to the cost of typical interior latex paint, and is aimed at a different task than what you're trying to accomplish, all of which will probably add up to very few actual uses in the real world.

 

[ThingsAbove]

I'm sure your wife will be hip to a lot of hanging foam baffles

 

[ardgedee]

Hang things from the ceiling? Fans, glass globes, mobiles, giant macrame tapestries?

 

[spatters]

One of the posters in the gearslutz/gearspace thread noted that the paint needed to be applied thickly, with a trowel, to produce a useful result when coating the inside of loudspeaker cabinets.

This strongly suggests that the paint works more by dampening the sympathetic vibrations of whatever it's painted onto than by preventing acoustic reflection -- sort of a paint-on soundproofing mat. The effectiveness of this treatment would depend on how prone the surface (in this case, drywall) is to sympathetic vibration in the first place.

In any case, if you apply it that thickly, you'll probably end up with walls and a ceiling that look like they're coated with Duraliner, which is likely not what you want. I suspect that cluttering up the room with lots of bookshelves (full bookshelves make great acoustic panels), furniture, and other bric-a-brac (including curtains and other fabric wall hangings) will produce much better results.

 

[silky smoove]

This strongly suggests that the paint works more by dampening the sympathetic vibrations of whatever it's painted onto than by preventing acoustic reflection

Correct. This was mentioned earlier in the thread by me and @AGCurry. The product is designed to limit transmission, not reflection, but by the limited number of available accounts, appears to do neither task very effectively.

 

[Aidenn7]

sound diffuser in front and behind the amp..

 

[Rip Van Dan]

I know in naval applications (ship and submarine hulls, for example), there are acoustic properties and sound frequency reflection properties that can be influenced by coatings - read SONAR. But that is quite different than aural hearing frequencies of LOUD music in a studio.

There's actually some sound dampening material in the Trident Submarines that was a big deal when it came out because it dampened vibrations and thus sound and made the Trident subs virtually impossible to find if they didn't want to be found. The manufacturer that the Orvis Company bought graphite from for their fly rods was the manufacturer of the these sound damping materials. So Orvis put a noodle of this stuff inside part of the rods and when you really started casting beyond about 40 feet the dampening made such a difference in casting efficiency that the line speed jumped way up. The line seemed to just jump of the end of the rod. Was great for Salmon, Steelhead and Saltwater. Didn't make much difference for trout because you are usually casting within about 30-feet of where you stand and it needed more weight and vibrations to really activate it.

Then Orvis included the vibration damping material in the handles of their rods for years. It was a thin wrap between the cork and the graphite and that gave a more gradual increase in power and tracking to the rod. Was a really big hit for a while until the next "best thing" came along. So there are some sound dampening materials like that out there but that's a pretty extreme example.

What I have seen though and I honestly have no idea how it works is some of those 12" squares of acoustic foam applied in patches in various parts of a room. We played a room that had a real tall ceiling a few years back and it was twice as long as it was wide. Everyone went direct to the FOH and they had a good sound tech. Folks who followed us to a number of different venues said that was the best mix of sound they'd ever heard from us. And they did NOT have a lot of those acoustic foam squares. They just seemed to have patches of them in strategic locations to deal with the bounce.

I'm sure there are folks here who know about strategic placement of sound absorbing materials, so hopefully they'll speak up and help clear the confusion.

 

[dbsfgyd1]

I don't see how it could possibly help you.

Acoustic paint is more commonly known as "soundproofing" paint, and it works for soundproofing by drying with voids embedded in the paint coat. Those voids provide acoustic insulation, like foam.

Echoes and reverberation result from sound waves bouncing around in a room. The treatment for those problems is not to cover the walls with some material, but to interrupt the sound waves within the room, using gobos, partitions, and traps. The furniture will help to some degree.

i’m going to but in here and than you for this advice. I’m having a house built. Several weeks ago when they completed the drywall in the room which I plan on using for musical pursuits, TV and such, I clapped my hands and boy did it ring. I’m glad you mentioned about furniture and carpeting can help tame it. I still think I’ll need some traps as well as partitions. I’ve never heard of a gobo. Guess I’ll have to google it.

 

[Greenstreet]

I know in naval applications (ship and submarine hulls, for example), there are acoustic properties and sound frequency reflection properties that can be influenced by coatings - read SONAR. But that is quite different than aural hearing frequencies of LOUD music in a studio.

Mm. They use four-inch-thick carbon-impregnated rubber tiles. Not really a "coating", per se.