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R/E/P => R/E/P Archives => Acoustics in Motion => Topic started by: Chris Griffith on January 07, 2009, 10:43:46 pm

Title: RFZ shaped control room..
Post by: Chris Griffith on January 07, 2009, 10:43:46 pm
I've been changing designs around a bunch for my new control room.  

I've finally decided to build a 10'x14'x19' room.  

The thing I cant decide is if to build it as a rectangle or have the walls go from 12' to 16' wide and ceiling angling from 9' to 11' (smaller in the front larger in the back).  I'd still be in the same 1:1.4:1.9 ratio.  

Is it worth the extra hassle of framing the room with angled walls and ceiling or should I just build a rectangle with absorption at the first reflection points?

The back wall of the room will be HEAVILY trapped and have RPG skylines for diffusion.

 
Title: Re: RFZ shaped control room..
Post by: Thomas Jouanjean on January 08, 2009, 06:52:15 am
When building a shaped control room, ratios that apply to rectangular rooms don't necessarily apply anymore - depending on the kind of shape. For cockpit / non-environmental / FTB rooms, they don't matter much at all anymore. Of course, your room still needs to have proper dimensions, but for other concerns than purely modal behaviour.

If you decide to build such a room, don't forget to leave a lot of space for the treatment on/of side walls and ceiling and think about the fact that LF surfacic behaviours is amplified in shaped rooms. Beware of treatment near and behind your backwall diffusors. You have to manage the LF energy that will go through them and avoid having re-emission and resonances there (which happens everytime and has to be adressed!).

Also it gets real complicated to calculate pressure points in shaped rooms, but take the time to do it right and pay close attention to all that during build.

But IMVHO, unless you know exactly what you're doing, I wouldn't put my fingers into room shaping - leave this to a designer, as it's so very easy to miss it.

Keep us posted!

Title: Re: RFZ shaped control room..
Post by: Chris Griffith on January 08, 2009, 06:34:56 pm
Thank you so much for the info!

So would you recommend just building a 1:1.4:1.9 ratio rectangle and treating it heavily?  

I have A TON of insulation (fiberglass,rockwool, and cellulose) I was planning on using in the room.  I have enough to fill about half the cubic space of the room if I needed to.  So broadband absorption won't be a problem.

I tend to like drier and darker sounding rooms so too dead is not a problem for me.  

Obviously this is your job and you can't design me a room but I'd love to hear any sort of advice you can give for a (relatively) foolproof decent sounding room.  I understand it won't be perfect since I'm doing it myself but hopefully I can build something that over time can be turned into something usable.    
Title: Re: RFZ shaped control room..
Post by: Thomas Jouanjean on January 09, 2009, 02:51:28 am
What's the exact type & density of the insulation you have?
Title: Re: RFZ shaped control room..
Post by: Chris Griffith on January 09, 2009, 10:20:55 am
I have a lot of varying insulation.  I have several contractors in my family and they've been saving me insulation left over from jobs for years.  

I have enough pink fluffy insulation (mainly R13 and R19, very little density) to insulate an average sized house.  It still has the paper backing which I'm planning on removing.  

Add to that about 30 bags of blow in cellulose still in bags and about 25 pieces of 2" and 3" rockwool used in my previous studio setup.  The rockwool is 8lbs per foot so its a little denser then 705.  

Title: Re: RFZ shaped control room..
Post by: Thomas Jouanjean on January 09, 2009, 12:13:13 pm
The pink stuff isn't too useful I'm afraid - but removing the paper on it is indeed a good step towards making it useable.

Lemme see what can be done with all this.

What type of speakers do you have? Have any quick drawing of your room?
Title: Re: RFZ shaped control room..
Post by: Chris Griffith on January 09, 2009, 09:11:48 pm
Here's a rough sketch of the space.  As you can see I'm limited to roughly 19' 6" in either length or width so I was thinking of building the room 10x14x19.  I could go larger if there's another ratio that would work.  Ceiling height can go up to about 12'6" inside the building.  

index.php/fa/10871/0/

Whatever space that isn't used up by the control room will be the lounge.  

I had always heard that pink stuff inside large traps was fairly effective.  I've seen a couple big build diaries that have gigantic traps filled with fluffy insulation and covered with a layer of rockwool or 705.  

Either way I have tons of insulation choices to choose from and am open to buying more if need be.  

Title: Re: RFZ shaped control room..
Post by: Chris Griffith on January 09, 2009, 09:16:33 pm
Forgot to mention speakers are focal twin 6's, adam a7's and NS10's.  

Once I'm done with the studio I'll probably be selling the focals and adams and buying a pair adam S3a's.  Unless of course the twins start sounding better to me in my new room.  
Title: Re: RFZ shaped control room..
Post by: rankus on January 10, 2009, 04:42:49 pm


Hope that bathroom has a decent exhaust fan  Shocked  Embarassed  Very Happy

Title: Re: RFZ shaped control room..
Post by: Chris Griffith on January 10, 2009, 04:51:09 pm
Actually I had to put a better one in there. It was no fun at all until I got a good one!  At least it has a fairly tall ceiling.  

Moving one of the walls out is on my list of things to do once the control room is finished.  

Title: Re: RFZ shaped control room..
Post by: Chris Griffith on January 14, 2009, 08:52:06 pm
I'm about to begin framing tomorrow and plan on building a 10x14x19 foot rectangle and figuring out the treatment afterwards.  

The doors will be placed in the middle back of the room so they won't be in the way of any corner trapping.  

Stop me if I'm doing anything wrong!
Title: Re: RFZ shaped control room..
Post by: Thomas Jouanjean on January 15, 2009, 02:11:18 am
Chris Griffith wrote on Wed, 14 January 2009 19:52

I'm about to begin framing tomorrow and plan on building a 10x14x19 foot rectangle and figuring out the treatment afterwards.  

The doors will be placed in the middle back of the room so they won't be in the way of any corner trapping.  

Stop me if I'm doing anything wrong!


Aarrgh, sorry, I didn't have time to have a good look at your room - so very busy here.

If you can wait for monday...
Title: Re: RFZ shaped control room..
Post by: Chris Griffith on January 15, 2009, 12:21:31 pm
Its too bad but I don't think I can.  

I'm getting help from my brother with the framing and have to work off his schedule.  We'll either begin this evening or tomorrow morning.  If it were up to me I'd wait but my brother and his company start a big job next week and I'll no longer be able to get his help.  

I'll still be looking for help as far as room treatments.  Hopefully the shell I'm building now will suffice.   At least it looks good using a mode calculator and I don't mind giving up a lot of space for treatments.  

I feel stupid for not waiting but I have no other options.. Sad
Title: Re: RFZ shaped control room..
Post by: Adam The Truck Driver on February 04, 2009, 02:54:24 pm
Are square rooms a bad thing? What if the tracking room and the control room are the exact same size and both are square? Should
each be acoustically treated the same, so that they sound the same with a given source in the exact same spot within each room or should one or the other be deadened to some degree?

Foregive me if this should be a new post, or if the exact information I desire is already here somewhere. I can never find it when they are using the search engine.

TYVM
AB
Title: Re: RFZ shaped control room..
Post by: Ethan Winer on February 04, 2009, 03:21:44 pm
Adam The Truck Driver wrote on Wed, 04 February 2009 14:54

Are square rooms a bad thing?


Yes. More here:

Graphical Mode Calculator

Quote:

What if the tracking room and the control room are the exact same size and both are square?


If the rooms are small you'd do well to remove the dividing wall and have one larger room, if possible.

Quote:

Should each be acoustically treated the same


Not necessarily. The goals for a live room are different from those for a control room. But the size of the room is a big factor. Without knowing that I can't even guess what to suggest.

--Ethan
Title: Re: RFZ shaped control room..
Post by: Adam The Truck Driver on February 04, 2009, 05:42:39 pm
This structure isn't yet built. The pad/concrete will be 27' wide and 42' long and the stucture itself will be a free span steel frame job so my ceiling will be fairly high. The side walls will likely be 14' high to match an adjacent building also not yet built, and there will be a 312 pitch roof most likely. Within this space, roughly 27x42 less the space of the 6 or 8 inch I beams and additional insulated interiour walls, needs to be a control room, and a live room, and an 8' wide hallway running the entire long axis of the building, for additional recording space and for rolling a piano from one place to another place in the facility. The size and shape of the control room and the live room I can eaily make into rectangle floor space shapes if that would be better than square. I would find it considerably easier to use 90 degree corners and parallel walls and utilize acoustic treatments rather than build those odd angled walls. The ceiling however can be quite high, even following the roof line which will be 21' high at least at the peak on a gable end. The adjacent stuctures will have spaces for recording also, one being a reverb chamber, and another for recording large ensembles should the need arrise. Edit: And a larger ISO booth/room. And I can make the control room 19' wide and 15' deep and the live room 19' wide and perhaps 24' deep. They can vary with the space of 19'x 39' I think will be the usable space, possibly 21' wide x39' long depending on the width of the hall.

EDIT:
On another note, is that spray in foam insulation any good for acoustic isolation of adjacent rooms/spaces, double wall of course with about 4" space between?

That is the best I can offer at this time.

Thanks
AB
Title: Re: RFZ shaped control room..
Post by: andrebrito on February 05, 2009, 06:05:36 am
Thomas,

when you talk about LF surfacic behaviors what do you mean by that ? modal behavior ?

In a shaped room modal behavior in terms of axial modes would actually be lower than in a rectangular room.

I think I'm not understating that term. Are you talking about re-emission of sound ?
Title: Re: RFZ shaped control room..
Post by: Ethan Winer on February 05, 2009, 02:05:16 pm
Adam The Truck Driver wrote on Wed, 04 February 2009 17:42

The size and shape of the control room and the live room I can eaily make into rectangle floor space shapes if that would be better than square.


Yes, and my ModeCalc program linked above will help you pick the best dimensions for your given slab size.

Quote:

I would find it considerably easier to use 90 degree corners and parallel walls and utilize acoustic treatments rather than build those odd angled walls.


That's fine.

Quote:

is that spray in foam insulation any good for acoustic isolation of adjacent rooms/spaces, double wall of course with about 4" space between?


Not sure, hopefully others here can answer that.

--Ethan
Title: Re: RFZ shaped control room..
Post by: Adam The Truck Driver on February 05, 2009, 02:53:55 pm
I tried that room calculator link thing, but couldn't get it to work for me.

Though now that entire space is nixed as is, in order to afford a better analog desk. Not nixed completely but rather it'll be moved up to the 3rd floor of my house...but anyhoo...I couldn't get the thing to work for me...I don't know why.

TYVM
AB
Title: Re: RFZ shaped control room..
Post by: Thomas Jouanjean on February 05, 2009, 03:25:20 pm
andrebrito wrote on Thu, 05 February 2009 05:05

Thomas,

when you talk about LF surfacic behaviors what do you mean by that ? modal behavior ?

In a shaped room modal behavior in terms of axial modes would actually be lower than in a rectangular room.

I think I'm not understating that term. Are you talking about re-emission of sound ?


To make the long story short - within certain conditions (freq is low enough, change of impedance between air and the surface X is high enough, incidence of wave is within certain boundaries) then the energy will literally start sliding on the surface X instead of being transmitted to it. When this happens, virtually no energy is lost while the enregy "slides" on that surface. That blurs a lot of the variables in real life.

The rest of this discussion should happen around a coffe Andre Smile
Title: Re: RFZ shaped control room..
Post by: Adam The Truck Driver on February 05, 2009, 04:18:08 pm
Ethan

I figured out how to get the program to work, but have no idea what these graphs and with the vertical lines and the numbers mean.

thx
AB
Title: Re: RFZ shaped control room..
Post by: Ethan Winer on February 07, 2009, 11:58:20 am
Adam The Truck Driver wrote on Thu, 05 February 2009 14:53

I tried that room calculator link thing, but couldn't get it to work for me.


What exactly happened when you ran it? There's nothing to install, just unzip the files to a folder and run the exe.

--Ethan
Title: Re: RFZ shaped control room..
Post by: franman on February 07, 2009, 11:36:56 pm
In our experience, all rooms, even multi-sided odd shaped geometry exhibit modal behavior. It just becomes much more complex (difficult) to predict the modal behavior in these odd shaped rooms. We have worked through many projects with odd shaped hard shells and found some methodology that works for us in determining (predicting) modal response. four sides, six sides, eight sides even round rooms have modes. Predicting the axial modes will just become a complicated exercise, thus being another reason (IMO) to leave shaped rooms to the professionals.

It's totally possible to build a great sounding control room in a properly designed and treated rectangle. It's much easier to predict and there's nothing wrong with it. IMO this is the way to go for most (if not all) DIY projects unless you are willing to do a little 'imperical' building (build it, try it, tear it down, repeat)... not many have the stomach or dollars for that!!

Cheers.... FM   Cool
Title: Re: RFZ shaped control room..
Post by: Chris Griffith on February 08, 2009, 11:41:14 am
franman wrote on Sat, 07 February 2009 21:36

In our experience, all rooms, even multi-sided odd shaped geometry exhibit modal behavior. It just becomes much more complex (difficult) to predict the modal behavior in these odd shaped rooms. We have worked through many projects with odd shaped hard shells and found some methodology that works for us in determining (predicting) modal response. four sides, six sides, eight sides even round rooms have modes. Predicting the axial modes will just become a complicated exercise, thus being another reason (IMO) to leave shaped rooms to the professionals.

It's totally possible to build a great sounding control room in a properly designed and treated rectangle. It's much easier to predict and there's nothing wrong with it. IMO this is the way to go for most (if not all) DIY projects unless you are willing to do a little 'imperical' building (build it, try it, tear it down, repeat)... not many have the stomach or dollars for that!!

Cheers.... FM   Cool



After reading this thread a bunch I'm really glad to have built a rectangular room.  I'm beginning to do treatment now and can tell its going to sound great.  The room ended up a touch off with a 1:1.41:1.89 ratio (hopefully thats close enough). The low end without treatment already sounds deep and natural.  

Before this I was in a room with terrible ratios and no matter how much treatment I added it never evened out.  My new room without treatment is already more even running sine waves then the old one that had massive amounts of deep traps on the back wall and plenty of rockwool panels in the front.  








Title: Re: RFZ shaped control room..
Post by: franman on February 08, 2009, 03:15:40 pm
Chris.. great.. let us know how it all works out.
Title: Re: RFZ shaped control room..
Post by: Chris Griffith on February 28, 2009, 11:00:47 am
I'm 95% done treating the room and from doing some sine wave sweeps it seems like I only have one broad peak between 105 to 120ish.  Everything else is amazingly even.

I still need to play with the speaker placement.  How far off the front wall should I place the speakers?  I have a feeling my peak has something to do with placement because it doesn't change much as I walk around the room.  

I'll be buying some software to run real tests next week but so far I'm extremely pleased with the room.  
Title: Re: RFZ shaped control room..
Post by: J.F.Oros on February 28, 2009, 12:18:12 pm
Chris Griffith wrote on Sat, 28 February 2009 18:00

I'll be buying some software to run real tests next week[...]

I don't think you have to spend money for what you want to do, you can use Room EQ Wizard (http://www.hometheatershack.com/roomeq/) a freeware but very comprehensive software for small room acoustical measurements.
Title: Re: RFZ shaped control room..
Post by: Chris Griffith on March 01, 2009, 10:55:51 am
I'm on a mac is the only problem.  

I can borrow a pc laptop though.  Would the cheapo stock soundcard be ok?
Title: Re: RFZ shaped control room..
Post by: J.F.Oros on March 01, 2009, 02:52:55 pm
I'm a Windows user, but on the REQW homepage on the requirements section it says that its working on OSX too.
Title: Re: RFZ shaped control room..
Post by: Bruno Gouveia on March 01, 2009, 06:47:43 pm
Thomas Jouanjean wrote on Thu, 05 February 2009 20:25


To make the long story short - within certain conditions (freq is low enough, change of impedance between air and the surface X is high enough, incidence of wave is within certain boundaries) then the energy will literally start sliding on the surface X instead of being transmitted to it. When this happens, virtually no energy is lost while the enregy "slides" on that surface. That blurs a lot of the variables in real life.





Arghhhhhhhh! So true... \stress

Hey Chris, what about some pictures?