My Live room

giles117 · Post by **giles117** » Sat Jun 28, 2003 3:58 pm

Here is a simple stick plan of my live room (Top View of course) Tell me what you think.....

Bryan Giles

Just alittle info. Floors will be floated and I will use clouds to calm the ceiling bounce down a bit. I will be cutting drums in here and due to my style of music, I do not want a LIVELY live room. But a nice sounding room. Not too live, not too dead. ANy and all advice will be considered and appreciated. Eric Desart Where you at......

Bryan Giles

Eric_Desart · Post by **Eric_Desart** » Sat Jun 28, 2003 5:44 pm

Giles,

That's one for John or the others.

Best regards
Eric

Sen · Post by **Sen** » Sat Jun 28, 2003 11:34 pm

would this make any sense..??
perhaps it would give you more room....you could use some hi freq. absorption (703 covered with cloth) on that door wall.
Juat a plain simple suggestion....hope something helps..

giles117 · Post by **giles117** » Sun Jun 29, 2003 12:07 am

Thanks sen. Hadn't thought of hangers in that corner wall. WHat do you think of Lenrds/Auralex 2" in that wall or is that a waste of efforts? Hate to just not use the product.

I have a Ton ($3,000) worth of auralex and Lenrd's (Anybody want some

) so I can use that on the side walls for HF Absorption to deaden that wall (door wall as you suggested)

And Eric... This IS one for you as well.

Your knowledge of physics can help me with some of the technical considerations. I am fielding suggestions to improve. I am probably more anal about my live room than the Mix room... Nah.. I am anal about both. I am looking for a nice balanced sound on the microphones from this room.

Your understanding of room modes matters here. Because of what I want to hear on a microphone.

I am looking for that small room ambient sound you get.

Like a RT of .6s and very LOW coloration from the room, but enough that if you got rid of the "verb" as it were, you'd here a loss of dimension.

So Trust me, I want your input. And please do not send me to one of those room calculators, I use MAC OSX and they run so slow on excel and have crashed excel 2 times. The Helmholtz Resonantor has not, but room modes did 2 times. (See, I tried it 1st)

Bryan Giles

Thanks for all input.

Eric_Desart · Post by **Eric_Desart** » Sun Jun 29, 2003 1:06 am

Hello Brian,

........And please do not send me to one of those room calculators, I use MAC OSX and they run so slow on excel and have crashed excel 2 times. The Helmholtz Resonantor has not, but room modes did 2 times. (See, I tried it 1st) ........

That's an interesting information to have.
Please don't eat me (I guarantee an indigestion, should even be too much for a Lion. I'm a Windows programmer, and however strange it may look, programming in Excel for Windows is different (certainly when complex programming syntax and graphic filters) than in Excel for Mac.

Can you give me the height?
Saw you gave length and width, then I do it for you and post the picture (it's a start to discuss).
RT60 is linked to room size and shape.
I'll tell you how much it is for pseudo live, live and very live.

Best regards
Eric

giles117 · Post by **giles117** » Sun Jun 29, 2003 8:54 am

LOL.. good come back.

Ok. ht with floor foated before clouds installed is 8'

Bryan

Thanks Eric.

Sen · Post by **Sen** » Sun Jun 29, 2003 12:53 pm

giles117 wrote:Thanks sen. Hadn't thought of hangers in that corner wall. WHat do you think of Lenrds/Auralex 2" in that wall or is that a waste of efforts? Hate to just not use the product.

I have a Ton ($3,000) worth of auralex and Lenrd's (Anybody want some ) so I can use that on the side walls for HF Absorption to deaden that wall (door wall as you suggested)

everything you have already is good and you should use it in combo with some suggested stuff.
The foam will surely do on the hi freq. absorption, so might as well use it

good luck

giles117 · Post by **giles117** » Sun Jun 29, 2003 3:03 pm

Hey Thanks, I am not sure wether you answered the one Question. Putting the Auralex behind the wall in addition to say 2" Rockwool.

Bryan

Sen · Post by **Sen** » Sun Jun 29, 2003 4:43 pm

I think if you put Auralex stuff anywhere, you wouldn't be putting it behind the walls...it should be exposed I think...

giles117 · Post by **giles117** » Sun Jun 29, 2003 9:01 pm

Oh Well I guess I'll sell it, I no longer want to look at it. the object is to construct a live room with none of that stuff exposed. I was playing with the idea of using it on the walls inside the resonator in place of say rockwool or SAFB.

Bryan

If you have an alternate layout with none of that mess I'd like to vibe with it. I start buliding that room after the 4th of July. My Control room should be done by Thursday of this week.

2 weeks of construction wonderful. (I barely worked 4 hours a day 3 days last week.) But I will be humping this week.

Floor is in, outer walls are in. Today (sunday) I do all the drywall then Monday I start the inside/sealed/angled walls should be done by Tuesday, framed and covered. Electrical gets finished when I frame those walls. Have to pick up glass and SAFB Monday....

Tuesday I will lay the Bruce Hardwood flooring (natural Oak) and stain it.

Hopefully no snags. Thank go I have nothing to mix till Saturday.

Bryan

Eric_Desart · Post by **Eric_Desart** » Mon Jun 30, 2003 12:40 am

Hello Bryan,

You wanted a RT60 of ca 0.6 sec.
That's impossible. This will sound as hell and you couldn't control modes and low drequencies anymore. Furthermore this RT60 = 0.6 sec will cause the diffuse reverberant field to become much too high, translated this means that the definition of your music disappears.

I calculated:
Pseudo live room: RT60 = 0.36 sec ; Schroeder freq = 214.0 Hz
Live room: RT60 = 0.41 sec ; Schroeder freq = 228.7 Hz
Very live room: RT60 = 0.46 sec ; Schroeder freq = 242.6 Hz

The Very live room is too live. You won't be able to control the sound field.
The Schroeder frequency is the frequency were the modal overlap becomes too small to get a nice diffuse field.

The modes are rather nicely distributed with the exception of 87.5 Hz. Here an axial and tangential mode coincides. (also a bit higher up) and the lower 67.9 (Tangential) and 70.4 (axial) is rather closely spaced.
Also the weighted number of modes diminish from the 80 to the 100 Hz band.

The problem aren't that much the modal behavior but the fact that the higher the reverb (think live room) the more explicit the impact becomes.
So you must control them without over-absorbing the room.

I really do not have the time now to go in-depth, just wanted to give already what I promised. The sizes are shown rounded to an inch but are calculated on exact sizes.

The idea will be that you use VERY good corner traps, which are very broadbanded (e.g. wool 703, membrane damper or Helmholz.
The walls should be provided with diffusers. Can be bend panels.
Possibly use the horizonatal corners (wall/ceiling too).
It's extremely important that you use absorption with relative flat behavior extending to verylow frequencies.

Mid and highs are easy to solve afterwards.
I should like to hear John's idea here.

That's all for now.

Kind regards
Eric

giles117 · Post by **giles117** » Mon Jun 30, 2003 6:43 am

I apologize, let me clarify. Imagine the sound that a TC Electronic Reverb puts out. Small room reverb .6sec decay.

It give a certain ambience and you do not "hear" the sound field, you feel the sound field.

That is the livliness I am looking for.

Bryan Giles

If I sound confused, of course you know this wen over my head. I tried to read an acoustics book and after the 2nd chapter put it away. Not something I wanted to get in depth about.

So anyway. I hope the above description given gives you an idea of what I am after, perhaps you can interpret the data for me so I can make heads or tails. (You probably did, but it blew right past me doing 75 MPH)

Eric_Desart · Post by **Eric_Desart** » Mon Jun 30, 2003 9:56 am

When you make a live room, you are bound by the properties of such a room. The size and absorption are important parameters.
Assume a contstant absorption of the walls/ceiling/floor and ignore, for the sake of argument air absorption.
The average path length that sound travels between reflections is 4*V/S.
This means for the same number of reflections at a certain spot the RT60 varies with this average path length in function of the size of a room.
This means that RT60 CAN NOT be seen as a constant but MUST be seen in function of the shape and volume of a room.

If you want to lengten the RT 60 in a room (without enlarging the room) you must decrease absorption, meaning you automatically get more reflections at any certain spot. You can not simulate a larger room because speed of sound is a constant, so by definition you need more reflections caused by less absorption at the room boundaries.

This increases the diffuse reverberant field dB level.

Bryan, I stop this here. I can't write a course about room acoustics in messages.

Summary:
In a room with the measures you describe you can not get a RT60 of 0.6 as resulting from your electronics.
The room defines what's possible.
In your room 0.41 sec is a good live room, which is already difficult to control, going somewhat higher and your room will sound like hell, and no treatment will solve that.

So for your room a good and live target is ca 0.41 sec, and your treatment must be designed to control those modes and low frequencies, and diffusers and/or room shape (non-parallel walls) must take care of the mid and higher frequencies.

Best regards
Eric

giles117 · Post by **giles117** » Mon Jun 30, 2003 1:43 pm

Please accept this compliment... I Understood what the heck you were saying. it made total sense.

Ok.

.41 it is. That should be cool. I suppose. I have the final design for this room. It should be done in 2.5 weeks from now. I will tell you how it feels to me.

Thanks again Eric. For making this make sense. I guess as a live sound engineer for 22 years I just know what I want to hear and know how to manipulate the gear to give me a "live" sound when I am in the studio. I am partial to that live sound.

I Own a Remote recording truck as well so I am used to the idiosynchracies of mixing an album recorded live, hence my taste in a room sound.

Bryan Giles