How to build control room in this place

[Christof]

Hi,

I've attached a picture to show what we have. The room marked with "Regie" (control room) has to be treated and I need ideas / comments about the "how to".

The facts:

Dimensions: (The wall on the right side has not been built yet and could be moved.)
- long wall: about 5,5m maximum (between curved wall and wall to WC)
- short wall: about 4,2m maximum (between curved wall and wall to the WC)
- distance between walls: 2,87m (wrong numbers in the picture)
- height: suspended ceiling without acoustic treatment.
height without suspended ceiling probably 3-4m (descending to the left)

Right now this place has walls with flaggin on all sides and a tiled floor. There have been changes to the plans: There will be no door needed to the "Band"-room (as the band won't be playing in there anymore), but to the upper room. There shall be something like an "isolation corridor" above (see the picture) and the door from the control room should go to that corridor, but it probably has to open to the side of the control room.

The concept I'm after looks like this (from the german "Studio-Magazin"-studio):


You can clearly see the construction of the wall: It seems to be a combination of a deflector (guiding the reflections away from the listening position) and an absorber (it's filled with absorbing material and open to the front).

The back should be as absorbent as possible and the ceiling could act as one big absorber too. On the front side they seem to have absorbers behind the speakers and in the edges too.

I don't know if we should change the floor. The walls will probably all get some framework / stonewool.

The problems:
Regarding first reflections and bass response it would be best to put the speakers on the right wall.

But it may be difficult to put a window in the wall to the upper room to see the musicians, as the "isolation corridor" may still cover that part of the wall.

Second problem would be the door, because it would open right into the area where the studio desk would have to be setup. If the door would be placed on the left side, it would be sitting in the wall between the control room and the studio - and we probably won't get enough acoustic insulation with that solution.

But putting the speakers on the wall between studio and control room (the upper one) would mean, that the reflections of the wall behind the listening position would come far too early and we even couldn't place good absorbers on that wall, because space would be quite limited.

Let me hear what you think...

Thanks, Christof

[Christof]

Here's a thumbsketch of my thoughts.

Regarding the window: Maybe it would be easier and even cheaper to use a camera and a flatscreen to solve that problem.

[Christof]

Comments anyone?

Or is this the wrong forum to ask?

[Ethan Winer]

This is the right forum, but your post was too general and didn't ask specific questions. At least that's why I didn't comment. The proposed speaker placement in your second post looks good.

--Ethan

[Christof]

Thanks Ethan,

well, I'd like any comments regarding this concept in general. But I'll also try to go more into details.

My idea is to optimize two things:
1. Minimize room modes by using large absorbers.
2. Minimize reflections by guiding the soundwaves away from the listening position

1. Minimize room modes
To reach that goal it would be necessary, that standing waves couldn't build up or will be absorbed. The room has no parallel walls between bottom and roof, and no parallel walls between front and back - it has parallel walls on the sides though.

We do not have money for a professional acoustic design and we need to find quite cheap solutions too.

So absorbers using cheap mineral wool / stone wool would be a good option (just besides: which one is better?) Using membrane absorbers would be more difficult I suppose, and probably more expensive too.

Ceiling used as one big absorber (about 14m²)
There are two concepts I'm thinking about:
1. I've seen slabs with/of mineral wool hanging down.
2. You could also make a construction of wooden joists with sheets of mineral wool laying on top of that.

What would be better - and why? Remember: The current ceiling is a supsended construction, but quite reflective. The roof behind that ceiling is descending - it's not flat. There is probably 1-2m space behind the current ceiling.

Back wall => Dead End
I want the back wall to absorb anything that's coming near it - minimizing standing waves and avoid any reflections back to the listening position.

The simplest way would be to just stack layers of mineral wool on top of each other from the bottom up to the ceiling. If I'd use the breadth of the mineral wool sheets, the aborber would be about 0,65m deep. So it would work quite good even for lower frequencies.

What would be the difference between an absorber as described above and one that would be thinner, with some space behind it, so the construction would have the same depth as the one above?

One more thing: I've seen diffusors on the back walls in many pictures of big studios. Is there a reason I shouldn't use an absorber?

2. Minimize Reflections

The wall behind the speakers:
I'd like to minimize reflections coming from this wall, as the result will be comb-filtering in the low frequency range. Will an absorber on that wall help or would it be necessary to soffit mount the monitors ("deadfront")?

I will need some cloth to cover the constructions (both the back and the ceiling) that will be acoustically transparent - but I don't want the fabric of the mineral wool to pass that cloth. Maybe a combination of a thin plastic membrane and a nice looking cloth to cover it up.
The problem I was thinking about: Would the result of this concept be a room sounding too "dead", especially in the high frequencies?

The side walls:
I'd like to construct something like "abflectors" working as an absorber for anything that goes behind it and reflecting soundwaves away from the listening position on its outside. (look at the thumbsketch in my second post). Is this a good idea or will there be any problems to be considered?

What about the floor?
I'd like to keep the tiled floor - please let me hear your advice, if that could be a problem.

That's it so far...

[gullfo]

what type of equipment are you using? will you be doing 5.1 or just stereo? what type of audio monitors?

[Christof]

We will use Stereo-Monitors - probably the EMES BLUE HR active (an earlier version, without the waveguide) or a combination of ADAM A7s with Sub 8. I'd prefer the EMES...

We will be recording / mixing using a DAW-software and a PC with two monitors. There won't be much more equipment - just the mic locker and a Midi-Keyboard.

[Christof]

Bump

[gullfo]

here's one thought - turn the CR around and use the odd corner for bass trapping and/or machine closet. put in a row of glass block in the front soffit to allow some natural daylight into the room. i'd put in a more rigid boundary close to the upper ceiling to make sure it was symmetrical left-to-right and maybe make it rise from front to back (window to door) and then hang absorbers as clouds but not line the entire ceiling.

[Christof]

Thanks Glenn,

I like the idea - just one thing I'm still thinking about:

The left monitor would be placed right at the concrete wall, the other would have the basstrap behind.
Wouldn't the bass response be affected by that difference?

Concering the ceiling: The roof nehind the suspended ceiling does rise from window to door already. So would it be a good idea to hang absorbers to the roof and cover the false ceiling with fabric?
Just to make sure: What do you mean with "hang absorbers as clouds"? Is it a construction like the one that can be seen in this picture?



Christof

P.S: And of course I'd like any comments about the concept or answers to the questions I listed above.

[gullfo]

the front soffit would be build out as an inside-out wall to avoid the backing wall problem and give you flexibility for a machine closet and bass trapping. overhead, you could build the false ceiling with the hangers - works for me. it sounds like you're shooting for a very dead room so the overhead false ceiling would do that, as well as side and rear wall absorption.

[Akshay]

i dont know much about this but a diffusive back wall would work the best with diffusors and put absorbers on the side wall,
this way you minimize reflections to the sweet spot (if RFZ design)
and retain the acoustic energy with the diffusors..

(correct me if i am wrong)

[Christof]

Resurrecting an old thread - we didn't have the money to realize this, but we will be able to start it now!

I have put more questions on John Sayers Forum - if you're interested you may have a look over here: John Sayers' Recording Studio Design Forum • View topic - Small control room in high school isolation and concept

Christof