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Church and H.O.W. Forums for HOW Sound and AV - Your Displayed Name Must Be Your Real Full Name To Post In The Church and HOW Forums => Church Sound Archive => Topic started by: Mike Rayle on November 13, 2007, 10:20:22 am

Title: Acoustic Treatment
Post by: Mike Rayle on November 13, 2007, 10:20:22 am
One of the many highest priorities that our church has after moving into our building is to treat the rear wall acoustically.

The building is a fairly standard shape for a traditional denominational church.  Narrow and long.  We have two "columns" of pews and center and outside aisles.  The building seats around 300.
The ceiling is very high and peaked.

The issue we have is that we aren't a traditional denominational church.  Our style of worship is the more contemporary amplified style.  This building was built so that an unamplified voice from the center/pulput area can be heard fairly well anywhere in the building.

We had an expert come in and recommend acoustic absorption on the rear wall and also bass traps in the rear corners.

He recommended Perdue Acoustics http://www.perdueacoustics.com for the panels.

In an effort to cut costs, someone has done a bit of research on DIY panels using stiff fiberglass boards.  I have seen a few websites that describe how to make these.

My questions to you are.....

Have you gone through a project like this and what was your experience?  Have any of you used the Perdue product?  Have you used the DIY panel approach?  Were you happy with the results?

My biggest concern is that in an effort to save money on the front end, we get something that doesn't solve the problem and we end up having to spend the money on the back end anyway.

Thanks!!!
Mike Rayle
Title: Re: Acoustic Treatment
Post by: Aaron McQueen on November 13, 2007, 12:35:28 pm
We go our panels from here:

http://www.atsacoustics.com/

The standard sizes are cheap and you can get custom sizes.  The custom sizes are about twice the cost of the standard sizes. You can order a sample kit to see if you like them.

http://www.atsacoustics.com/item--Executive-Sample-Pack--sam plepack.html

We purchased the fire treatment.  Make sure it meats your local code, or you'll be taking them down when the fire marshal comes through.
Title: Re: Acoustic Treatment
Post by: Brad Weber on November 13, 2007, 06:02:33 pm
Did they recommend any particular panel thickness, total area of panels, mounting locations, etc.?  Any specific type of mounting, such as furred off the wall, or non-standard panels, such as impact resistant or low frequency tuned panels?

If they are basic 1" or 2" thick fabric covered, fiberglass panels, then there are probably a much larger number of options available.  Perdue Acoustics is one of the better known brands, the biggest difference between them and most other brands is that they use rockwool rather than fiberglass for the core in their panels.  If you want to compare other brands, look at the octave band absorption coefficients and make sure that you are looking at the same thickness, mounting and test procedure.  Testing done with the panels spaced out or with a Type E mounting with an airspace behind the panels can give higher ratings than panels that were tested butted together or as a direct applied Type A mounting, so sometimes what seem to be two equivalent products based on the numbers are not due simply to the details of the testing procedure used.

Unless you have some good finish carpenters and someone familiar with working with fabric on frames, I have seen few DIY panels that looked like manufactured panels.  It can be done, but can be more difficult than it seems and you usually get it all figured out just as you finish the last panel.
Title: Re: Acoustic Treatment
Post by: Andrew Stoeber on November 13, 2007, 10:53:58 pm
I made some DIY absorbers for behind our drums. They are great for our purposes. It cut 3-4 dB out in the room, and there is a big difference to the drummer without everything bouncing around so much back there. You can learn alot by reading stuff by Ethan Winer and around on forums, and it is a little cheaper if you do it yourself....you can also make custom size panels for your purposes.

Here are some pics of our project http://entertainment.webshots.com/album/561141897vDZTvE

We used 3" mineral wool and 2" rigid fiberglass...the project (for screws, wood, insulation, respirators, everything) cost us 160$. If you are just doing 2" rigid fiberglass and covering it in fabric, it would be alot cheaper. If you are just wanting to kill reflections then using mineral wool or fiberglass and covering them is no different than ordering pre-made panels.  The trick is finding an insulation supplier area that carries the stuff. There are some big chains like SPI and BWI that are around though.

Hope that helps...

Andrew Stoeber
Title: Re: Acoustic Treatment
Post by: Bruce Burke on November 14, 2007, 07:25:37 am
I a church you want more diffusion than absorption. If you suck out too much, the congregation won't sing out.

You really need to contact Joe at his website:

http://www.jdbsound.com/

He has DIY plans for panels in his book that are for specifically designed for church acoustics. There is also a bunch of good info on his website.

You can also help your cause with the right speaker. From the building you have described, you may want to investigate the Electrovoice EVI series, which were specifically designed for rectangular rooms.

-Bruce
Title: Re: Acoustic Treatment
Post by: Brad Weber on November 14, 2007, 09:40:18 am
Perhaps you missed this in the OP,
Quote:

The issue we have is that we aren't a traditional denominational church. Our style of worship is the more contemporary amplified style. This building was built so that an unamplified voice from the center/pulput area can be heard fairly well anywhere in the building.

We had an expert come in and recommend acoustic absorption on the rear wall and also bass traps in the rear corners.

Some design and consulting firms like to assume that every church is the same and has the same needs and goals.  That way they can just skip any needs analysis and sell the same thing over and over.  The reality is that almost every church is unique and different both architecturally and in their needs and desires.  Mike's church hired someone to provide them recommendations for their specific situation, unless there is specific reason to question those recommendations, it seems inappropriate to do so.
Title: Re: Acoustic Treatment
Post by: Rob Warren on November 14, 2007, 02:41:39 pm
WEll the reality is even "experts" or hired guns all do things
differently so I don't think the previous poster was "missing"
any info, I think he is just simply disagreeing with the treatment.

I think what we need is more information.  
What problems are happening?  Is it a delay / slap coming from the back wall?  Is it RT-60 factor? that meaning the room is too live and it's decay time is too long for contemporary worship.
Is it a certain frequency that is hanging in the room being a problem?  This all and a lot more is determined when treating an acoustical problem.  

Chances are it will take more than just the back wall getting treated.  Side walls and ceilings can be just as bad or worse.'

Also one last thing to remember.  When using these absorption panels make sure you don't absorb all the higher frequecies and leave all the low mids to rumbling around the room.  
Title: Re: Acoustic Treatment
Post by: Brad Weber on November 14, 2007, 04:38:26 pm
Rob Warren wrote on Wed, 14 November 2007 14:41

WEll the reality is even "experts" or hired guns all do things
differently so I don't think the previous poster was "missing"
any info, I think he is just simply disagreeing with the treatment.

Disagreeing based on what?  Have they been in the room?  Do they know the existing room finishes or any of the problems?  Your comments actually support the point, why would you disagree with someone else's recommendations without knowing any of the things you noted?  I'll assume that the person the church hired has been in the room and does know the situation better than us and I don't see anything in the recommendations noted that would make them seem obviously inappropriate, especially in light of Mike's comments regarding the room and services.

Quote:

The issue we have is that we aren't a traditional denominational church. Our style of worship is the more contemporary amplified style.

Quote:

I a church you want more diffusion than absorption. If you suck out too much, the congregation won't sing out.

This is what I ws referring to.  How does congregational singing relate to what was said was wanted?  If they are a contemporary church that relies heavily on the sound system then adding absorption is likely a very valid treatment while adding diffusion may have minimal benefit, especially given that the space "was built so that an unamplified voice from the center/pulput area can be heard fairly well anywhere in the building".  Combine this with a recommendation for a speaker that apparently someone thinks is the answer for any rectangular room regardless of dimensions or application (not the first time this has come up) and it seems like trying to apply a generic solution to a room for which it may not be appropriate.

FWIW, the book referenced is unavailable.



Title: Re: Acoustic Treatment
Post by: Bruce Burke on November 16, 2007, 07:53:27 am
Brad Weber wrote on Wed, 14 November 2007 16:38

Rob Warren wrote on Wed, 14 November 2007 14:41

WEll the reality is even "experts" or hired guns all do things
differently so I don't think the previous poster was "missing"
any info, I think he is just simply disagreeing with the treatment.

Disagreeing based on what?  Have they been in the room?  Do they know the existing room finishes or any of the problems?  Your comments actually support the point, why would you disagree with someone else's recommendations without knowing any of the things you noted?  I'll assume that the person the church hired has been in the room and does know the situation better than us and I don't see anything in the recommendations noted that would make them seem obviously inappropriate, especially in light of Mike's comments regarding the room and services.

Quote:

The issue we have is that we aren't a traditional denominational church. Our style of worship is the more contemporary amplified style.

Quote:

I a church you want more diffusion than absorption. If you suck out too much, the congregation won't sing out.

This is what I ws referring to.  How does congregational singing relate to what was said was wanted?  If they are a contemporary church that relies heavily on the sound system then adding absorption is likely a very valid treatment while adding diffusion may have minimal benefit, especially given that the space "was built so that an unamplified voice from the center/pulput area can be heard fairly well anywhere in the building".  Combine this with a recommendation for a speaker that apparently someone thinks is the answer for any rectangular room regardless of dimensions or application (not the first time this has come up) and it seems like trying to apply a generic solution to a room for which it may not be appropriate.

FWIW, the book referenced is unavailable.






Church sound involves more than being able to hear an unamplified voice from the pulpit or using a PA system to amplify electronic keyboards or play tracks.
Title: Re: Acoustic Treatment
Post by: Brad Weber on November 16, 2007, 09:16:57 am
The correct environment is what the church wants it to be.  With few exceptions, the physical space and the church's goals and vision differ for each church.  Trying to impose a single standard or assuming that every church is the same ignores the reality that each church and even every space are unique.  In my opinion, providing recommendations without first identifying the actual requirements and expectations for that project does the church a disservice and is not good design.  Of course, many people apply the same criteria and solution to every project simply because this is easier and less effort than actually having to determine what is desired and/or because they don't really know what they are doing and this approach allows that.

Okay, we're not helping the OP here.  My point was simply that I don't believe that any of us have been in the space or talked to the church.  I assume the person that made the recommendations for them has.  We don't know who that person is or how they derived their recommendations, it may have been someone very qualified who performed a detailed analysis.  So unless there is some direct conflict between what was identified in the OP and what was recommended, then why contradict it?  Is it simply because it isn't what you did in another church?
Title: Re: Acoustic Treatment
Post by: Don Lanier on November 25, 2007, 07:54:53 pm
Ive recently been involved in a large church project needing the same acoustical treatments and I understand that its difficult for the end user or church lay person to understand what they are trying to convey to you. After a initial visit where we took laser measurements, performed acoustic testing across the frequency band, attended a service and tested, and consulted with the Architect, we decided on a suggested treatment to reduce the RTA time of the room down from 7 seconds to 2.5, Now explaining why a sound system needs to be done in a certain fashion is difficult to these folks, explaining and then selling the Acoustical treatment is Way more difficult. The terms aren't familiar and without a good idea of Physics and Math its going to be extremely hard making the Church Board understand why there spending 10,000 dollars or more to fix the issues left by poor room design of the 2.5 million dollar church.

There are many manufacturer's of these products and all of them do a good job, there are differences of opinion on what types of treatments, Wall, Cieling, Baffles, Clouds, Wood, Cloth, Fiberglass, Cotton, 1" OR 2" etc, WHATS BEST...After evaluating most of the major brands on the market we looked at several local products as well as well as the DIY versions. Cork Board, Homosote, and Carpet, By doing some research you can find a chart that lists the NRC Rating of most available materials in varying thicknesses and see what works best.

Finally what it comes down to is installing enough materials to bring the RTA Down to an shorter time and this will increase intelligibility and be a more desirable environment for your Church. Diffusion, Diffraction, Absorption, Traps are all types of terms used to describe the end result and how this will be achieved. There are always several vendors doing these installations and I suggest you simply get another bid,
But at some point you must trust the expert or go about attempting to correct the problem with DIY projects that can be costly and not achieve the correct response. Fire retardant ratings are a must for any material's used in a public space and these materials should meet certain building codes and safety criteria.

Good Luck

Title: Re: Acoustic Treatment
Post by: Bruce Burke on November 26, 2007, 11:55:55 am
Brad Weber wrote on Fri, 16 November 2007 09:16

The correct environment is what the church wants it to be.  With few exceptions, the physical space and the church's goals and vision differ for each church.  Trying to impose a single standard or assuming that every church is the same ignores the reality that each church and even every space are unique.  



How many churches have the technical savy to know what they need? If they did, would they be looking for help?

To say each church is unique may be true, but the psychoacoustic requirements are unchanging.

Indeed, someone needs to sit down with them and explain the things they don't understand and what the options are and what the benifits and consequences are of each possibility.

Don Lanier has it right.
Title: Re: Acoustic Treatment
Post by: Brad Weber on November 26, 2007, 02:13:16 pm
Bruce Burke wrote on Mon, 26 November 2007 11:55

How many churches have the technical savy to know what they need? If they did, would they be looking for help?

I believe that the churches do know what they want, at least in terms of their own ministry and vision.  The job of the acoustical consultant, or of any technical or design consultant, is to develop solutions to support those goals, whatever they are.

Quote:

To say each church is unique may be true, but the psychoacoustic requirements are unchanging.

?????  Maybe I'm just misunderstanding what is being said.  Are you saying that an Orthodox synagogue, a Roman Catholic cathedral, a traditional Protestant church and a contemporary Christian church (that sounds like the start of a joke...) all require, or even desire, the same acoustical conditions and environment?  That the same criteria and goals can be applied to all forms of worship and any space?  If so, then I would have to strongly disagree.

Quote:

Indeed, someone needs to sit down with them and explain the things they don't understand and what the options are and what the benifits and consequences are of each possibility.

Agreed, but I feel that a critical part of that effort is listening to the goals and needs expressed by the church and supporting those in what is presented rather than presenting a solution based on assumed goals and then trying to direct the application to fit that solution.  Unless you are designing to a standard set by the church or governing authorities, the design process should be a process of exploration and adaptation.  Any design or analysis should first assess the project's needs and expectations and then use that as the basis for developing solutions.  Admittedly, this entails being sufficiently skilled and knowledgeable to develop varying solutions and address differing goals, but it really seems to be the only way to properly serve each project.

Added: This is becoming much more a philosophical discussion and unless others see any benefit to it, perhaps we should move offf line with any further discusssion.
Title: Re: Acoustic Treatment
Post by: David Sumrall on November 26, 2007, 10:59:13 pm
Hey Mike,

Did your pro give you specifics on which exact pieces to get, where to install etc??

Or was it not as specific and just a general put something on the wall kind of advice??

Did he do audio measurements to help with those specifics??

I think everyone here wants to help, but a little bit more clarity would be helpful before real opinions can be made and advise given.

As to the build it your self concept... remember what you build may or may not give you the same results as the specified pro stuff. I would want to do it right and only once if possible.

I would not mind saving money by purchasing real product and installing it ourselves.

If cost is an issue then you could work on installing it in phases to spread cost around a bit. Maybe put some in at the end of this year and the rest in at the top of 2008.

One trick I will use if given no other option for diffusion is to put some tall fake plants along the reflective wall. I have to do this in one of our rooms that has a lot of glass on the back wall sometimes. It does not fix everything but it does help.

Good luck!

David Sumrall
Technical Director/A1
First Baptist Orlando