R/E/P Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: [1] 2 3 ... 6   Go Down

Author Topic: Diffusor dimensions for backwall of my new controlroom  (Read 23072 times)

Constantin

  • Jr. Member
  • **
  • Offline Offline
  • Posts: 93
Diffusor dimensions for backwall of my new controlroom
« on: March 28, 2009, 06:37:35 pm »

Hello erverybody.  Razz
I´m happy to found this great Forum, since the information about acoustics, i read here, is the best and detailed i found until know.

I hope somebody can help me with my questions about diffusion at the backwall of my new controllroom which i build at the moment.

The rough basic plan looks like this:

http://img208.imageshack.us/img208/8639/miksmietshauslayout1.jpg

Celling high is 3,3m at the front, and about 3,5m at the back.

Today i buyed some wood for a skylinediffusor.
The standard size for the wood is 58mm X 58mm, so the maximum diffusion frequnecy is set to about 2968Hz.

http://img24.imageshack.us/img24/2329/diffusorc.jpg


Is this a good frequency for this room, or is it nessesary to cut the wood in 50mm X 50mm for example to get a higher maximung diffusion freqency??
The lowest frequency is calculated to 570Hz so i can stay in my 30cm maximum depth.

What do you think about this plan?
Which range of diffusion would you prefer?
Maybee better a QRD ?

I hope to find helpfull response in this nice place.
here are some photos from the build today:

http://img208.imageshack.us/img208/6683/bild017.th.jpg

http://img257.imageshack.us/img257/8647/bild018z.th.jpg

http://img256.imageshack.us/img256/8660/bild019q.th.jpg

http://img23.imageshack.us/img23/2361/bild021o.th.jpg



cheers
Consatntin

Thomas Jouanjean

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 342
Re: Diffusor dimensions for backwall of my new controlroom
« Reply #1 on: March 29, 2009, 06:19:16 am »

Welcome to R/E/P!

Before you build your skylines, I would recommend you take a second look at a few things:

- Side walls treatment - quid?
- The area where your diffusors are placed also needs specific bass freq management - which is missing.

I.e.: you pbly have some heavy pressure zones right behing your sweet spot. This requires immediate attention before you take care of your diffusors.



Logged
Thomas Jouanjean
Northward Acoustics - Engineering and Designs
http://www.northwardacoustics.com
http://www.facebook.com/pages/Northward-Acoustics/1062876633 71

Pro Audio Partners:
ATC Loudspeakers
FOCAL Professional Speakers

Constantin

  • Jr. Member
  • **
  • Offline Offline
  • Posts: 93
Re: Diffusor dimensions for backwall of my new controlroom
« Reply #2 on: March 29, 2009, 08:46:20 am »

Hello Thomas and thanks for your reply  Smile


FOr the Sidewalls i plned to have not much porous absorbers, because i`m afraid that the room gets to dead.

In plan is only one 10cm thick porous absorber between the window and the soffitwall, for shure at booth sides of the room  Razz

At the floorlevel i want to build 30cm thick and 1m high boxes, which can be used for perforated absorbers, if nessesary. Tuning this absorbers is planed after roommesurements.

between the window and the door i thougt about using a big polyfusor, but im not shure at the moment, if this is a good idea, so i will read more about this kind of diffusor.

Over my head there will be a big cloud 35cm thick hanging 20cm down from the celling.

Is it realy nessesary to have basstraps also behind the diffusors since i have a huge basstrap all around the celling/wall corners which is 80cm high, and 70cm deep??? (You can see the frames at the photos)
When i need also basstraping behind the diffusors, which kind is the best? A membrane, or helmholz?

thanks for your help.

cheers
constantin  Smile

Thomas Jouanjean

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 342
Re: Diffusor dimensions for backwall of my new controlroom
« Reply #3 on: March 29, 2009, 01:34:19 pm »

I wouldn't tell you so if it isn't going to be a problem.

Lots of trapping doesn't make sense if half of it is in the wrong place.

How did you come up with this geometry?
Logged
Thomas Jouanjean
Northward Acoustics - Engineering and Designs
http://www.northwardacoustics.com
http://www.facebook.com/pages/Northward-Acoustics/1062876633 71

Pro Audio Partners:
ATC Loudspeakers
FOCAL Professional Speakers

Constantin

  • Jr. Member
  • **
  • Offline Offline
  • Posts: 93
Re: Diffusor dimensions for backwall of my new controlroom
« Reply #4 on: March 29, 2009, 01:45:39 pm »

Quote:

Lots of trapping doesn't make sense if half of it is in the wrong place.

yes.
All my research until know goes to the same direction: "treat as much corners in the room as you can". This the the goal i want to reach with all the basstraps all around the celling/wall corners, and also the backkwallcornertraps.

Quote:

How did you come up with this geometry?

The angeld walls are like they are , to avoid flutters between the sidewalls,reflecting sound around the sweetspot of the CR, allow a bigger recordingroom, and have good visual contact to the recroom.

I hope this was not the most bad way to go Shocked

cheers
constantin

Thomas Jouanjean

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 342
Re: Diffusor dimensions for backwall of my new controlroom
« Reply #5 on: March 29, 2009, 02:19:39 pm »

A good advice that was given here a few threads ago by our esteemed Francis and others is that unless you know exactly what you're doing, shaped rooms should be avoided...

http://recforums.prosoundweb.com/index.php/t/26474/19234/

Of course, it doesn't mean yours is bad! Not at all!

But the pressure points and energy spread are very hard to calculate. And so many things go into calculating those that it's easy to miss it... And those rooms are very unforgiving.

On the trapping thing, corners are one of the important zones to treat, absolutely. But don't over do it either as other surfaces need to be treated, which are just as important. If you're scared the room will turn too dead there are many ways to incoporate treatment for LF behind a structure that will reflect MF/HF.

My advice really is to work a bit more on your LF treatment scheme since you're not too far in the build sequence. Smile

Logged
Thomas Jouanjean
Northward Acoustics - Engineering and Designs
http://www.northwardacoustics.com
http://www.facebook.com/pages/Northward-Acoustics/1062876633 71

Pro Audio Partners:
ATC Loudspeakers
FOCAL Professional Speakers

Constantin

  • Jr. Member
  • **
  • Offline Offline
  • Posts: 93
Re: Diffusor dimensions for backwall of my new controlroom
« Reply #6 on: March 30, 2009, 10:34:53 am »

Thanks for reply thomas. Smile

I will reconsider  the basstrapping in the room.

Do your company also offer only making pressure-diagramms of a room.
Something like this calculation for rectengular rooms:

http://www.hunecke.de/en/calculators/room-eigenmodes.html

When not, is it a possibility to put my spekers inside and just walk around with a measurement mic to find the pressurepoints?


Just for intrest:
I remember a studio with a Glass QRD at the backwall of the Controlroom. i think it was Much Music but i`m not shure Rolling Eyes
Do you think there is also a kind of basstrapping behind the diffusor,because the QRD is also a window, or do you think they put the traps somewere else?


cheers
Constantin

Thomas Jouanjean

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 342
Re: Diffusor dimensions for backwall of my new controlroom
« Reply #7 on: March 30, 2009, 01:30:22 pm »

We can indeed calculate the geometry for you, based on existing conditions.

On the glass diffusor, if it is used as a window, then the trapping of LF can come from the window letting the LF out... Or they just didn't deem it necessary. So could be either meant to be LF "transparent" or a design choice. All depends on the window thickness too.
Logged
Thomas Jouanjean
Northward Acoustics - Engineering and Designs
http://www.northwardacoustics.com
http://www.facebook.com/pages/Northward-Acoustics/1062876633 71

Pro Audio Partners:
ATC Loudspeakers
FOCAL Professional Speakers

franman

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 580
Re: Diffusor dimensions for backwall of my new controlroom
« Reply #8 on: April 02, 2009, 10:11:37 am »

I have to agree with Thomas, that I would be concerned about proper broadband bass trapping (before tuned resonators and before the diffusors). Bandwidth of a diffusor is a big topic in itself. We like to build larger sequence QRD these days with deeper overall dimension to spread the bandwidth in both directions. The overall size you're looking at looks appropriate for the room...

Remember that not treating the side walls "too much" can be bad. Where ever you want to control ER or do trapping, I would recommend as a rule of thumb that you think full bandwidth. The only thing worse than hard early reflections, are bandwidth limited early reflections (just low mids)... Then the comb filtering caused gets even weirder to deal with.

There are plenty of surface you can keep "live" so your room isn't "too dead" (I don't typically worry about this that much and our control rooms may be on the deader side from some others), but floors, rear side walls, front walls, etc can all be hard surfaces (depending on speaker geometry).

This also brings up the whole discussion of the front wall speaker installation. I'm not sure what you're planning for the "Soffit Wall/Bass Trap"... I wouldn't recommend a 'soft wall' for an in-wall speaker installation. Like I said, it's a whole other discussion!!

FM
Logged
Francis Manzella - President, FM Design Ltd.
                 - Managing Director, Griffin Audio
fmdesign.com
griffinaudiousa.com

Constantin

  • Jr. Member
  • **
  • Offline Offline
  • Posts: 93
Re: Diffusor dimensions for backwall of my new controlroom
« Reply #9 on: April 03, 2009, 09:44:48 am »

Hi Fran and thanks for your reply Smile

It is hard for me to belive that treating ALL corners in the room, expect the floor-wall corners, with min 66cm deep porous absorbers, is that way too little broadband basstrapping Shocked

But when You and Thomans say this, i have to belive, because you have to know it better.

Don`t you like the idea of a peforated absorber at the floor-wall corners 1m high and 30cm deep, reservating for basstrapping after meassurements?
I can tune this pannel also broadband when needed.

Edit: Uppps ,i saw that i don`t talk about the celling-wall traps  before.. Embarassed but you can see the frames in the pictures Very Happy  

For the firstreflection points:

Did i understad it right that 10cm deep porous pannels are to small for the sidewall firstreflektions?
Is 15 cm enough or is it nessesary to spend more room for thesde pannels?

The Window is placed in an angel so that reflections are reflected aroud the sweetspot.
I used the pincipal of lightbeams for this. incoming angel= reflekting angel.



What do you think about the 35cm cloud?


To the backwall:

maybee i can afford 20cm behind the diffusion for basstraping, for maximum.

But I´m not sure of the overall benefit, because when i bring the diffusors forward the distance between the diffusor and the wall makes the diffusor becomeing a third leaf, what will reuce my lowfreq. isolation to the next room??

PS:

I saw Egan Sound is your projekt..
Nice! i followed the construction thread at john`s site, from beginning and was very impressed by the build.
This was the time i started to get intressted in acoustics.


cheers
Constantin



Constantin

  • Jr. Member
  • **
  • Offline Offline
  • Posts: 93
Re: Diffusor dimensions for backwall of my new controlroom
« Reply #10 on: April 10, 2009, 05:49:38 am »

Hi


in the moment it is not sure if i can finish this projekt, sice i have to stop building because of healthy problems, and don`t have the money to pay a company to do the work.
i will search for solutions the next week, and when there is no way for me, i will stop the projekt. Sad
Sice your replys, i think anyhow it is a not working plan, so i will push the emergency button.
In the moement i`m very frustrated because i spend all my energy and money in this projekt, and can`t finish it because my body say`s NO.
I`m praying for a wonder, and we will see the result next week.
happy eastern to all of you Smile


cheers
constantin

Steffen

  • Jr. Member
  • **
  • Offline Offline
  • Posts: 59
Re: Diffusor dimensions for backwall of my new controlroom
« Reply #11 on: April 10, 2009, 06:06:26 am »

I was following this thread with interrest. good luck you man. hope you recover quick!

steff
Logged
http://www.diygallery.de/forum/DIYgallery.gif
www.diygallery.de
Steffen Mueller

franman

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 580
Re: Diffusor dimensions for backwall of my new controlroom
« Reply #12 on: April 10, 2009, 10:51:06 pm »

Constantin,

My wishes for a quick recovery... hope you feel better and can keep the important things on track! Feel better.

FM
Logged
Francis Manzella - President, FM Design Ltd.
                 - Managing Director, Griffin Audio
fmdesign.com
griffinaudiousa.com

Thomas Jouanjean

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 342
Re: Diffusor dimensions for backwall of my new controlroom
« Reply #13 on: April 28, 2009, 11:57:24 am »

Constantin, feeling better?
Logged
Thomas Jouanjean
Northward Acoustics - Engineering and Designs
http://www.northwardacoustics.com
http://www.facebook.com/pages/Northward-Acoustics/1062876633 71

Pro Audio Partners:
ATC Loudspeakers
FOCAL Professional Speakers

Constantin

  • Jr. Member
  • **
  • Offline Offline
  • Posts: 93
Re: Diffusor dimensions for backwall of my new controlroom
« Reply #14 on: April 28, 2009, 02:05:45 pm »

Thanks for your wishes

The bad news are that i don`t feel better, more wose Sad
I´m waiting for a operation which is set to the 27.05.09
until this date i must lay down.
i can`t sit, can`t stand, can` walk, just rest in bed.
And at the other hand: while i can`t work, i get no money.

i`ts not the best year for me until know
hope things will change soon

cheers
constantin
Pages: [1] 2 3 ... 6   Go Up