Acoustic Help Needed ASAP...

[EBAC LD]

Hey guys,
Most of you are probably familiar with my future sanctuary that I have made several post on... No, the sanctuary is still not ours, and its looking like it will be another year before it is.

Here is my problem, we are being forced to move into it in 2 weeks due to the smaller sanctuary being at max capacity and us still growing every Sunday.

The other church is also still using the larger sanctuary for its traditional services, so us doing anything permanent to it is still out of the question.

In a nut shell, I have 2 weeks to do some kind of acoustic treatment in this room. Do I have enough money to do it complete and to hire a professional, no... Im not asking for criticism on how im not doing it right, I am just asking for help to try do some something to this room to get it a little better for our services.

You can find the room dimensions and pictures in this thread Speaker Questions. The room has carpet on the lower section, and bare floor on the upper section. The walls and ceiling are drywall. The main problems with the room are slap echo from the rear wall to the stage, and reverb time. The current reverb time in the room is about 3 seconds.

I will probably only have the money to do one section (upper or lower), and the rear wall, not the entire room. Going with ATS 2x4x2 panels, where am I better off placing the panels to get the most out of what little I can do?

Any response is greatly appreciated.
Justin

[BenHT]

This isn't going to help with your actual question but just in case it's helpful I'd like to advise to be especially good at looking after your crew and the band during the move. We had to move out for a couple of months last year and my parents' church moved to a school as they grew. I think we did well and used it as a team-building-exercise-type time; at my parents church the band fell out with each other and this (I think) led to the congregation halving

Everything will be new and difficult especially the first time. Hope it goes well!

(Also - be very interested in pix of what you do end up doing as the room looks similar to our place except much wider and we have a flat ceiling with beams. We used to have no problem with echos/reverb until the ceiling was replaced with a harder material and now it's pretty bad.)

[EBAC LD]

Thanks for your comments Ben.

On the acoustic question... Has anybody seen these http://www.audimutesoundproofing.com...-blankets.aspx portable absortion sheets?

They are not very thick, and only have a NRC 0.70 but I think for ease of use and being able to take them down easily it might be our best option... Any thoughts?

Justin

[cmchamp]

In your situation, any product that won't cost an arm and a leg and be temporary will be a good choice. Until you have a qualified acoustician come in and evaluate your room and make recommendations, the room will never sound as good as it could.
Remember, the space (if I remember correctly) was originally designed for acoustic instruments and music with speech reinforcement systems only.
The RT60 times and acoustical footprint (RT60 and different frequencies) is different for a room designed for traditional acoustic music than that for contemporary sound system driven.
C.

[Brad Weber]

I can't pass up pointing out the comment in the referenced thread that "The room will be treated by a professional acoustic company before the audio is done." Something about the best laid plans of mice and men... However, this does bring up the question of what is happening due to the temporary overlapping use. For example, are the side balconies being removed as previously planned or will there be no major physical changes for now? Will you be using the existing audio system or supplementing it in some way?

The acoustical issues with that space may not be just those you noted. For one thing, the reverb time may be radically different with a full congregation and the people in the room might have more effect than any temporary treatments. Problems like any slap back off the rear wall might depend on having people in the room, what you do to modify or supplement the sound system and so on. I do wonder if the curved ceiling might be a concern and one that any temporary treatments would likely not impact. Similarly, I wonder if the side walls are a potential concern for flutter echo for any noise in the congregation.

I wouldn't focus on NRC numbers for products when addressing music, NRC values are an average over several frequencies and the performance at those frequencies can vary significantly for material with the same NRC number, especially if the NRC ratings allow for absorption coefficients larger than 1.0 that can arise from the standard test procedures. Values of 0.1, 0.8 and 1.2 and values of 0.7, 0.7 and 0.7 both average to 0.7, but those are obviously two different situations and this is the type of situation that can occur when using single number values. One things I would consider is that apparently the published absorption numbers for the Audimute blankets is based on their being mounted 3" off the surface behind them, that air space definitely affects the results and you could get much different absorption, and probably lower absorption at low frequencies, if the blankets are mounted much less than 3" off the reflecting surface behind them.

I agree with Cory that on a short term, temporary basis that such treatments might help. However, in that situation I would probably look at either treatments that could then be reused elsewhere later on or at truly temporary treatments such as filled wall hangings or even sleeping bags. Or perhaps consider renting some staging and heavy curtains, these might also be easier to move around and experiment as well as possibly being easier to store if they need to be removed between services.

[cmchamp]

And to add to what Brad brought to the discussion today regarding "The room will be treated by a professional acoustic company before the audio is done" line.

Anyone who sells products that claim to be acoustical in nature can call themselves a "professional acoustic company." This has been brought up in the past that the ability of these companies to truly address the specific issues of your room, worship style, etc. questionable at best, unless they actually visit your room and do a gamut of acoustical tests.

An "Acoustician" or "Acoustical Consultant" will run a gamut of on-site tests, request blue-prints, make drawings, take pictures and measurements. They then will design a solution that addresses the specific needs of your room with combinations of diffusion and absorption across the entire bandwidth, including frequencies below 250Hz as necessary.

Again, as I mentioned before, there are different reverberation characteristics for different styles of worship, be they acoustic or contemporary, and any Acoustician or Consultant should understand and know that.

C.

[tedanderson]

Im not asking for criticism on how im not doing it right, I am just asking for help to try do some something to this room to get it a little better for our services.

I second the motion for some thick and heavy pipe & drape. Also, you might want to see if there is a local carpeting wholesaler or warehouse who would be willing to loan you some rolls of carpeting and padding to stand up against the wall. If you can find someone to agree to it (e.g. you would be offering them "free" storage) you would need several guys to carry and stand up the rolls.

[EBAC LD]

I agree that the room does change some with a crowd but its still to live for us. The curved ceiling is alot of our problem but it's here to stay until the room is ours. The balconies are staying up now also.

The current sound system (TOA "line arrays") is what we will be relying on, but I will be adding some bottom end to it...

I really do hate to spend that much money on the absorption sheets, and really its not looking like I will get the money for it. So, if you feel the rolls of carpet and thick blankets will help, ill look into it.

[cmchamp]

Here's a less expensive "blanket" option.
http://www.tecnec.com/SearchProduct.asp?off=0&sort=prod

[BenHT]

Hey Cory,
That link doesn't work - looks like it's their search results page but doesn't include what you had searched for... Though I'm guessing "blanket" is what you searched for... ooo they're cheap.

[cmchamp]

Yes, that's what I searched on. Sorry.
Also, if you have any members of your congregation that work for a moving company, you could see about borrowing moving blankets for your services.
Unfortunately, any of these solutions, due to their guestimetology - the art of acoustic-audiological prognostication - are really similar to throwing "dead cats" at the problem. (term borrowed from another forum).
C.

[Brad Weber]

Originally Posted by cmchamp

Unfortunately, any of these solutions, due to their guestimetology - the art of acoustic-audiological prognostication - are really similar to throwing "dead cats" at the problem. (term borrowed from another forum).

Someone's been hanging around Crusty Russ too much...