Room Acoustic Help!

[jdsimons2]

Hello!

I'm seeking some help with Acoustic Panel placements, and where a good place to purchase acoustic panels are. I was looking on realtraps.com and saw they were priced right around $150-$200.

I'm trying to get by with finishing off the room the cheapest way possible. So any estimations for how many panels, where to purchase, and where to place would be very helpful!

Below is a picture of the room. Basically, there are two speakers and the room is rectangle!

 

[jdsimons2]

Oh, and the lights are no longer hanging. They are in the ceiling now.

 

[ParadigmDawg]

The least expensive way is to build them yourself. All it takes is some #8 mineral wool, some simple frames and some cheap fabric that you can easily breath through.

I have close to zero handyman skills and I built some for around $35 each and they looked fine and worked great.

If I was buying complete panels I would go with GIK.

A compromise between the two would be purchasing the frames from Ready Acoustics.

I have done all 3 of these.

As far as placement, minimum would be one behind each speaker, one at both first reflection points and a few on the back wall. Glen at GIK would talk to you and tell you what you need. Most acoustic companies offer a free service to help you decide.

These were my GIK panels:

Ready Acoustic panels, you purchase the frames and add your own Mineral Board and fabric:

I cant seem to find pictures of my DYI panels.

 

[jdsimons2]

Thank you! That's very helpful. What's the best way to figure out the First Reflection Point?

 

[ParadigmDawg]

Thank you! That's very helpful. What's the best way to figure out the First Reflection Point?

Have someone set in the primary listening position and hold a mirror at your side and parallel to the side wall. Start beside the speaker as close as you can get to the wall and start walking towards the back. When the person setting in the LP can see the speaker, that is the first reflection area.

 

[nibhaz]

Have someone set in the primary listening position and hold a mirror at your side and parallel to the side wall. Start beside the speaker as close as you can get to the wall and start walking towards the back. When the person setting in the LP can see the speaker, that is the first reflection area.

^THIS^ +1 QFT


jdsimons2 is there a particular acoustical issue you are trying to solve?

 

[GIK Acoustics]

Thank you! That's very helpful. What's the best way to figure out the First Reflection Point?

Others have posted the way I would go about it. For a visual representation with some explanation, check out our video we did on first reflection points here: Early / First Reflection Points - GIK Acoustics

 

[jdsimons2]

^THIS^ +1 QFT


jdsimons2 is there a particular acoustical issue you are trying to solve?

So, this is what happened:

Before, the room was setup the short way. Our stage was against the left wall, so there wasn't that much of an echo problem. Also, the room ONLY was used for music.

However, we remodeled the room, moved the stage to the far end wall, and also started using the room for other activities. Changing the orientation of the stage has driven our musicians and sound guys nuts with, I guess the term is, "reflections".

Also, when we have 50 kids in the room running around, playing, and screaming, it gets SUPER loud and VERY echoey.

I want to eliminate both of those problems by putting up panels. Since the problem isn't ONLY from the speakers, I'm thinking I'll need to line the walls up quite a bit with panels, rather than just at reflection points.

Others have posted the way I would go about it. For a visual representation with some explanation, check out our video we did on first reflection points here: Early / First Reflection Points - GIK Acoustics

Thank you for the video! This helpful and I'll use this as I put up my panels

 

[jdsimons2]

The least expensive way is to build them yourself. All it takes is some #8 mineral wool, some simple frames and some cheap fabric that you can easily breath through.

I have close to zero handyman skills and I built some for around $35 each and they looked fine and worked great.

If I was buying complete panels I would go with GIK.

A compromise between the two would be purchasing the frames from Ready Acoustics.

I have done all 3 of these...

What did you put INSIDE the panels? Is it the wool? Is this something that can be purchased at your local hardware store?

The way I understand it is:
- Build wood frame
- Put wool inside
- Wrap in breathably fabric

Am I missing anything in that process? Is the wool attached to the frame in some way or does it simply sit inside?

 

[nibhaz]

Jdsimons2 this is the method I've used to build panels with great success.

most questions you might have about the process are answered in the comment section of the video



As far as your particular problem it sounds like you are describing flutter echo which is basically caused by excessive amounts of parallel flat surface areas i.e. your big empty room with nothing on the walls and no furniture or objects besides the stage.

Basically you want to minimize the number of parallel flat surfaces by either placing stuff in the room or by hanging three dimensional objects and/or acoustic panels asymmetrically to whatever you hang on the opposing parallel wall. Randomness is your friend.

Three dimensional objects which create diffusion in combination with absorption from acoustical panels should provide you the more natural sound environment you are seeking.

Cheap three demsional objecs include shelving with stuff on them, bookselves with irregulaly sized books, any type of artwork that has depth of a few inches or more.

If you want to get real serious about the room you can google QRD Diffuseers and Poly Diffusers. Both can be either made DIY or purchased.

 

[nibhaz]

BTW the video I posted is for making 4" traps which is good for absorbing mid bass level frequencies. You can make 2" traps which are not effective at low frequencies but will be more than adequate for reducing flutter echo.

Also you should be aware that a panel's low frequency absorption rate can be enhanced by placing an air gap behind the panel

 

[ParadigmDawg]

What did you put INSIDE the panels? Is it the wool? Is this something that can be purchased at your local hardware store?

The way I understand it is:
- Build wood frame
- Put wool inside
- Wrap in breathably fabric

Am I missing anything in that process? Is the wool attached to the frame in some way or does it simply sit inside?

Use either #8 mineral board or Corning's 703

MINERAL WOOL 1280 (8 lbs/ft) 48"x24"x2"



Owens-Corning Acoustic Insulation - Acoustic Insulation - Acoustic Insulation & Materials

A home improvement store won't have it but an industrial HVAC place will. I found a place that sold it by the sheet locally. It was around $17 per sheet.

 

[Gordonj]

I would recomend going with pre-made panels and not building this yourself.

How old are the kids running around? You may need to go with a panel that is a little better at not being torn apart.

I would recommend going with pre-made panels and not building this yourself. Since it is a public space you need to make sure the panels are fire rated in some form. Most pre-made 1" panels you can find around $6 to $7 per sqft. That is for a basic panel with guilford grill cloth covering. The standard panels come in 4'x8'.

The problem you are having is a common problem with "shoe-box" room layouts and the solution is reducing the loudness levels in the space. The excessive loudness is caused by incorrect ceiling height to room size. The only thing you can do is put absorption panels on the walls. Don't worry about exact locations at this point. The entire room is a problem so you have to increase the absorption coeffiects in the room and try and reduce some of the loudness levels. I would start with 50% of each wall getting covered with absorption. Don't worry about reflection or de-fraction just simply absorb the noise.

In an ideal world you would want various levels of absorption to maintain the balance of the frequecy response in the room. However, I sense that you don't have a lot of money to deal with so, shoot for a 2" panel but worse case go with a 1" panel.

Acoustic Wall Panels

A100 Series Acoustical Panels

There are many many more but that should give you an idea.

Once you get the walls covered you may need to do something on the ceiling to control the reflections but the recommend treatment level above should have a major impact and be noticeably "better".

This room will never sound great or even really good but you can make it livable...

Gordon