ProSoundWeb Community

Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => SR Forum Archives => Installed Sound/Contracting FUD Forum Archive => Topic started by: jeffhtg (Jeff Kenney) on August 08, 2008, 02:51:39 PM

Title: creating sound deadining panels
Post by: jeffhtg (Jeff Kenney) on August 08, 2008, 02:51:39 PM
I can't find this in the search and I know some people have talked about it before. I have a room that is going down to brick and need to make some acoustic panels for a very large hard surface. Looking for something that could be painted.. anyone got any hot links?
Title: Re: creating sound deadining panels
Post by: Tom Young on August 08, 2008, 03:15:10 PM
Almost anything used for absorption cannot be painted without losing a significant degree of effectiveness.  The exception would be absorptive material with a fairly open type of grill (over it) such as perf metal.

Diffusive treatments are much more likely to be paintable without disrupting what they have been designed to do.

If it is absorption that you need, I suggest you first decide what type to use (area of panels, their thickness and the distance from the wall or ceiling) and then wrap them in a fire-rated fabric that matches or compliments your surrounding interior architecture.
Title: Re: creating sound deadining panels
Post by: Chad Johnson on August 08, 2008, 03:40:56 PM
I always us Tectum Panels. They come on large sheets, they can be painted. Fir them out from the wall with Roxull fire rated fibre wool behind and your good to go. With a two inch insulation behind they are very broad band and very absorbent.  Everything is fire rated and paintable to match any decor with out hurting fire or acoustical performance. You'll want to spray them first and touch up with brush/roller once installed. The website has all of the ratings for absorption coefficients with different combinations of spacing and insulation.

Polycylindrical absorbers for bass and mid/hi diffusion can be painted as well.
--Chad
Title: Re: creating sound deadining panels
Post by: Duane Massey on August 08, 2008, 07:34:28 PM
+1 on Tom's reply; you can build the panels in any shape that appeals to you, and even do them in varying layers.
Title: Re: creating sound deadining panels
Post by: SteveKirby on August 08, 2008, 07:43:24 PM
If you do some research into RPG diffusers, you will find that in spite of the convoluted math used to make them sound special, the actual progression of cavities is quite straightforward and easily managed in a decorative remodel.  Kind of like a "quadratic" waveguide being one with a straight flare.
Title: Re: creating sound deadining panels
Post by: John Birchman, CTS on August 09, 2008, 09:02:15 PM
ATS Acoustics has both pre-made panels in assorted sizes and colored coverings (ASTM E84 fire rating as option), as well as selling the materials for diy.

http://www.atsacoustics.com/

John
Title: Re: creating sound deadening panels
Post by: Dan Chujko on August 09, 2008, 09:44:17 PM
FYI, Tectum panels have a couple of issues but seem to be widely used.

On an installation of a TV/production studio that I was brought in on after the fact, the contractor decided to save a few bucks and order the 4'x 12'panels instead of the standard 4'x 8' sheets.  The GC mounted the sheets long ways (12' wide - horizontal)with the wall studs too far apart (according to the mfg)and after a few heating/cooling/high humidity cycles the tectum bowed and dipped to the point that it looked like a 20'h x 68' basket weaved wall!!!  A true ugly & costly situation for the GC.

Also tectum even in the best scenario of max depth from back of product to structural wall does not absorb very well from 500 Hz and below.

Original topic was sound panels.  Was the OP looking absorbing, stopping or both?
Title: Re: creating sound deadening panels
Post by: Chad Johnson on August 10, 2008, 04:00:30 AM
Dan Chujko wrote on Sat, 09 August 2008 18:44

FYI, Tectum panels have a couple of issues but seem to be widely used.

On an installation of a TV/production studio that I was brought in on after the fact, the contractor decided to save a few bucks and order the 4'x 12'panels instead of the standard 4'x 8' sheets.  The GC mounted the sheets long ways (12' wide - horizontal)with the wall studs too far apart (according to the mfg)and after a few heating/cooling/high humidity cycles the tectum bowed and dipped to the point that it looked like a 20'h x 68' basket weaved wall!!!  A true ugly & costly situation for the GC.

Also tectum even in the best scenario of max depth from back of product to structural wall does not absorb very well from 500 Hz and below.

Original topic was sound panels.  Was the OP looking absorbing, stopping or both?


Good question, I assumed absorbtion panels.

I fir Tectum panels with 2X2 and/or 2X4 and have never had a bowing problem and always use 12 foot lengths. I've found them quite accurate for down to 250hz or so and then go to corner traps or poly diffusers for absorbing lower freq's.

I like them because they are fairly simple to use, fairly cost effective, can be painted to match any decor, and are fire rated.
Title: Re: creating sound deadining panels
Post by: Brad Weber on August 10, 2008, 10:03:45 AM
Chad Johnson wrote on Fri, 08 August 2008 15:40

Everything is fire rated and paintable to match any decor with out hurting fire or acoustical performance.

Tectum has a Marketing Bulletin specifically on this topic where they define using one specific paint that comes in 50 gallon drums and very specific environmental conditions, sprayer characteristics, etc. for the application.  They also state that the panels should be painted in place and brush and roller application are specifically not recommended.  The fact is that it is quite easy to adversely affect the performance if one does not follow the manufacturer's recommendations.

There are actually two steps involved in interior acoustical treatments.  The first is determining what are the proper treatments, then there is figuring out what products meet those requirements.  These requirements usually go beyond the acoustical performance to include aspects such as durability, impact resistance and of course, cost, but they will affect what is appropriate and some more information of the application or specific requirements would help.  Blanket application of any product without consideration for the application is poor practice.  For example, even on a basic level the solutions may be quite different if this is a boardroom or a gym or if the sources are speech versus full range music and so on.  
Title: Re: creating sound deadining panels
Post by: jeffhtg (Jeff Kenney) on August 10, 2008, 08:27:17 PM
The room in question is a nightclub. My problem is every wall is "armored" in plywood. I have done my best to array the speaker system to keep it off the walls - but in some places that simply cannot be done. I'm looking for general HF absorption in these areas where direct HF energy is exposed to solid walls.
Title: Re: creating sound deadening panels
Post by: Dan Chujko on August 10, 2008, 11:29:24 PM
The room in question is a nightclub. My problem is every wall is "armored" in plywood. I have done my best to array the speaker system to keep it off the walls - but in some places that simply cannot be done. I'm looking for general HF absorption in these areas where direct HF energy is exposed to solid walls.

Depending on what you consider HF . . .

If start with 1KHz and up there is a wide variety of products that are affordable.  Now it depends on your budget and if you or a contractor is going to install the material

It is not rocket science but sometimes it ends up being penny wise and pound foolish not to have a contractor to install the product.

PLEASE make sure you use a fire rated product that both your local inspector and your insurance company will approve in writing.  If you are in the club business you will remember that ugly situation a few years back.
Title: Re: creating sound deadining panels
Post by: Chad Johnson on August 12, 2008, 12:20:48 AM
Brad Weber wrote on Sun, 10 August 2008 07:03

Chad Johnson wrote on Fri, 08 August 2008 15:40

Everything is fire rated and paintable to match any decor with out hurting fire or acoustical performance.

Tectum has a Marketing Bulletin specifically on this topic where they define using one specific paint that comes in 50 gallon drums and very specific environmental conditions, sprayer characteristics, etc. for the application.  They also state that the panels should be painted in place and brush and roller application are specifically not recommended.  The fact is that it is quite easy to adversely affect the performance if one does not follow the manufacturer's recommendations.

 

Yes Brad, that is a good point. The sprayer PSI etc is speced by Tectum. I have spoken with Tectum reps about the painting procedures and their instructions to me confirmed regular latex paint will work fine in most applications (as has been my experience). They also offer paint advice where mildew/mold is a problem. A couple of coats of regular latex should not affect acoustic properties and this is done everywhere they are used. However, when giving advice online, I think it's best to go by the book and mention the protocols as outlined by the manufacturer, thanks for pointing that out.

When applying them to a wall in an existing building where overspray is an issue, IMHO, I have found painting them first is best. Again, I was told the reason they are recommended to be painted on the wall is because they are somewhat brittle and can flake away on the edges while being flexed and lifted and fastened into place. I found that to be accurate and that's why I suggested touching up with a roller/brush once they are put up (and spraying first).

You are also very correct in your thoughts on blanket statements are not helpful. There are many ways to address acoustics. Placements, bandwidth, absorption, diffusion, durability, cosmetics, material cost, labor cost, "fasten-ability" are all factors and no one method is best in all cases. Tectum is just one approach. I've had good luck with the product and it worked well in four specific installations I've done in the past few years.

I enjoy these threads because I am always trying to find innovative and differing approaches to acoustical issues. What are some of the absorption approaches you have found work (with a  good balance of cosmetics, durability, cost, labor, etc)?
Title: Re: creating sound deadining panels
Post by: Brad Weber on August 12, 2008, 12:13:14 PM
If done properly it may be very feasible to paint some acoustical products, but will that attention to detail be maintained over time?  I have seen too many projects where as part of a renovation or simple sprucing up people end up painting over acoustical plaster, acoustical panels, etc. without any special consideration, only to negate much of the acoustical benefits of those materials.  So my reluctance with painting acoustical materials is greatly based on experiences with long term issues when in a few years people assume that since a material was already painted they can just get out the old brush and whatever paint they're putting on the walls and slop some paint on.

The question on what materials I typically recommend brings up an interesting point.  I certainly understand the desire to use DIY solutions in many situations, but as a Consultant I usually have to avoid them.  With DIY solutions or modified products the resulting acoustical performance is generally unknown and even if estimated, can add a large degree of uncertainty into any analysis.  Manufactured products typically have laboratory derived acoustical performance data available to use in any analysis.  If you simply want to do something that should help, DIY may be a viable option.  However, if you want a specific result or someone to say with any certainty that a solution will resolve specific problems, which is typically when a Consultant gets involved, then you almost have to base the solutions on known products for which reliable performance data is available. So many Acoustical Consultants do not avoid DIY products because of any profit motive or ties to manufacturers but rather because they need to work with products with a known performance and that is generally impractical with DIY products.

For a club type situation something like http://www.kineticsnoise.com/interiors/conform.html, or http://www.kineticsnoise.com/interiors/knp.html or http://www.kineticsnoise.com/interiors/ksp.html might also be an option (there are other manufacturers of similar products).  I've used similar products in animal habitats and prisons, so some club patrons might be right at home with them!
Title: Re: creating sound deadining panels
Post by: Ivan Beaver on August 12, 2008, 09:03:25 PM
I have seen a good number of spaces that have acoustical problems and claim they have acoustic panels.

Well they do-somewhere 8o-under all that paint Laughing .  The panels are covered up with so much paint as to make them useless. Mad
Title: Re: creating sound deadining panels
Post by: Gene Hardage on August 20, 2008, 11:53:37 AM
jeffhtg (Jeff Kenney) wrote on Sun, 10 August 2008 20:27

The room in question is a nightclub. My problem is every wall is "armored" in plywood. I have done my best to array the speaker system to keep it off the walls - but in some places that simply cannot be done. I'm looking for general HF absorption in these areas where direct HF energy is exposed to solid walls.


Can you get the owner to look into spraying certain areas with cellulose?  I think you can paint it and they have some kind of fire retardant stuff they mix it with when they spray it on.