Confused about absorbing highs, mids and lows.

[soonerrob]

Hi everyone... new guy here...

First I want to apologize in advance to anyone that is reading this post for the second time... because I also posted this same thread on Ethan's forum..

Here goes.



I have inherited a 20' x 22' x 12' monster of a room with hard plaster walls and ceiling and hard vinyl tile floor... can you say echos?

I play drums and will primarily want to use the room as a live play/recording room... anything from drums to guitars, etc.

The room already has 2" wedge foam installed from the floor, 3ft up on two joining walls, the entire length of each wall, and no other treatment.

I have read Ethan's FAQ quite thoroughly and it talks about absorbers for both highs/mids and bass.. and that you need both...

I am about to embark on making my own absorbers from 703 and wood frames...

My question is:

In order to do an adequate job of absorbing not only bass but high/mids... do i need to construct absorbers at different thicknesses of 703?

or

Do I just make them all 4" thick and rely on placement to absorb all frequencies properly? ie. corners vs. walls and/or against wall vs. away from wall.

also...

Does building absorbers do away with a need for plywood type surfaces at multiple offset angles or even curved shapes as shown in the faq for surfaces left "live"?



any help is MUCH appreciated...

and thank you very much for this forum... I can't wait to get started.

Rob J

p.s.
Here are some pics of the room.

[Glenn Kuras]

In order to do an adequate job of absorbing not only bass but high/mids... do i need to construct absorbers at different thicknesses of 703?

No. You can make them all 4" or thicker. For true bass absorption you do want to straddle corners, but even for the early reflection points 4" is always welcome as it is hard to get enough bass absorption in most rooms.

Does building absorbers do away with a need for plywood type surfaces at multiple offset angles or even curved shapes as shown in the faq for surfaces left "live"?

Yes in no. I think you are talking about diffusion which is always welcome in a room and with your room being large I would recommend it.

Here are a few links to help understand things a bit better.

Diffusion is a Wonderful Tool by Jeff Hedback
What Are Early Reflection Points. SPOTLIGHT:Bob Ebeling - Revolution Studio
GIK Acoustics: Room Setup

[soonerrob]

Thanks Glenn...

Im just trying to make sure I understand how to best trap the massive echoing in this very reflective room...

right now I have highs mids and lows bouncing around quite freely.. the foam did make a nice difference... but I want to finish off the room properly.

Is placing 2'x4'x4" absorbers in both corners and spaced out around the walls and ceiling the method I am going to use to accomplish this?

Im just trying to make sure that im understanding that absorbers will treat highs, mids and lows... or is it absorbers for lows and diffusers for highs and mids..

I think its the fact that everything seems to be referred to as "bass traps" that is confusing me about how to properly treat highs and mids.

Thanks again for the quick answer.

[Glenn Kuras]

Is placing 2'x4'x4" absorbers in both corners and spaced out around the walls and ceiling the method I am going to use to accomplish this?

Yes

I think its the fact that everything seems to be referred to as "bass traps" that is confusing me about how to properly treat highs and mids.

Well there are different kind of "bass traps" out there. Tuned bass traps are ones that focus only on a certain frequency range and to be honest most smaller rooms need more broad band bass trapping. Meaning you have problems through out all the frequency range (lows, mids and highs). With the broad band you can lessen the high end (recommend for corners and non early reflection areas) absorption by using FRK on the fronts.

You may want to keep doing some reading around here and our education page to get a full understanding of this stuff. But don't over think it too much.

[avare]

Originally Posted by soonerrob

Thanks Glenn...

Im just trying to make sure I understand how to best trap the massive echoing in this very reflective room...

right now I have highs mids and lows bouncing around quite freely..

This is adding to what Glenn wrote. What you are describing is flutter echo. Spread out the absorbers evemly as possible on the 5 surfaces (the ceiling is a surface) trying to have patches of absorption opposite reflective wall areas on the opposite side.

Andre

[soonerrob]

Glenn.. thank you very much for the details..

Ill update the thread as I go with new pics...


Andre...
Thanks for mentioning the staggered placement with the opposite walls... I would have overlooked that...