Studio design in a barn

[ward]

First remark, the height he specifies (2,55m (8foot37) untreated) is far too low.
The brick walls are 3,50m so it's easily obtainable to keep 3m untreated space.


The steel beam in the middle should be moved a bit to go in between the control and live room:


Any comments about the floorplan design ?

[gullfo]

the floor plan looks good. why does the architect think the walls are only 2.7m high?

[ward]

the floor plan looks good. why does the architect think the walls are only 2.7m high?

Beats me ??
I've made him a very detailed drawing. He probably thinks that 2.55m internal height is enough.

To explain the situation a little:
He's the architect for our house, he's not an acoustic expert, and doesn't claims to be.
We have someone who has more expertise in acoustics who he consults from time to time.

I still have to wait now to know the budget for this structure,
whether it will be steel, wood or concrete block pillars with beams on it.
It all depends on the cost, steel is probably the most expensive

[gullfo]

why do you want to put heavy things on the ceiling? one option would be to add a deck with the proper support for storage so the isolation ceiling is not burdened with the support for arbitrary weights.

[ward]

As you might notice there's a 5 year gap here ...
things got hectic and the house came first.

So where am I at right now,
http://smg.photobucket.com/user/perki/s ... dio%202015
I have a steel reinforced concrete ceiling, 360kg/m2
the ceiling is suspended on steel beams,
these steel beams are sitting on big 0.8mx0.8mx0.8m blocks of concrete underneath the original walls,
The floor is at least 17cm of steel reinforced concrete.
This leaves me with a
height of 2,9m
width of 6m
length of 10m

This space is now my rehearsal space for R&R-band with a LOUD drummer.

Where I wanna go from here :
- injection of the original brick walls against rising damp in these walls (that are filled with salts)
- about 5cm PUR/PIR with aluminium layer against these brick walls, to prevent the salts from coming into the airgap.

I have genelec 1032's that I'd like to use as big monitors, Emes black TV's as nearfields.

I believe I wanna drop the small voice booth.
I'm not confident in what I wanna do with the space, one-room recording space or live/control room.
Your opinions ?

One of the first thing that is mentioned in acoustic books is the room ratio, but in my original plan all inside walls are in an angle non 90 degrees. Is it possible to calculate room ratios? Is it a bad idea ? Should I go with rectangular rooms?

[Soundman2020]

I'm not confident in what I wanna do with the space, one-room recording space or live/control room.
Your opinions ?

You don't show any dimensions on your diagrams, so it's hard to say, but it does look like you have enough space to do a small control room and a small live room.

One of the first thing that is mentioned in acoustic books is the room ratio, but in my original plan all inside walls are in an angle non 90 degrees. Is it possible to calculate room ratios? Is it a bad idea ? Should I go with rectangular rooms?

Use one of these Room Ratio calculators to figure out the best dimensions for your room:
http://www.bobgolds.com/Mode/RoomModes.htm

http://amroc.andymel.eu/

Both of those are very good, and will help you to decide how best to build your room.

Those calculators only provide accurate prediction for rooms that are rectangular, or close to rectangular. It's a good idea to do that, though, even if your room is not truly rectangular, as it will still give you a rough idea of how the modal response will be.

- Stuart -

[ward]

Thanks Stuart.

I updated the plan with some dimensions.


I tried the room ratio calculators with average widths, and It seems to be ok for the control room.
control room : 5.5mx4mx2.7m

The live room : 5.5mx5.3mx2.7m is not ok!

[Soundman2020]

There's no need to angle the walls like that. You can if you want (for example, if you are trying to do an RFZ or CID design concept), but in that case they only need to be angled as far back as the mix position. And the rear of the room should not get narrower: it should get wider, or stay the same width.

- Stuart -

[ward]

Thanks Stuart,

There's no need to angle the walls like that. You can if you want (for example, if you are trying to do an RFZ or CID design concept), but in that case they only need to be angled as far back as the mix position. And the rear of the room should not get narrower: it should get wider, or stay the same width.

When I poured the concrete floor I made a 2cm gap between the mixing room and the live room.
I did this in the diamond shape like in the drawing 2 posts up.
This was done to avoid crosstalk.
Would you prefer to make the rooms completely rectangular and ditch the existing gap in the floor ?

I was also trying to minimize flutter reflections, possibly out of a lack of real knowledge?
Reading another thread in which you commented:

From "Small Studio in Finland" thread: You are wasting space by splaying the complete side walls like that. You only need to splay (angle) a small part at the front of the room, roughly as far back as the mix position. From there to the back, the walls can be parallel, to increase the total volume of the room. If you end up with flutter echo problems like that, then it's easy to treat those with absorption panels on the walls (and you will probably need those in any event).

The same problem happens with the way you are cutting off the rear corners of the room. That wastes space, and those corners are where your bass traps need to go.

[Soundman2020]

When I poured the concrete floor I made a 2cm gap between the mixing room and the live room.

Hmmmm... that's a problem! It means that you are locked into those shapes and dimensions now.

You have three options:

1) Use them as they are, with the CR shape not being optimal.
2) Modify them by cutting the slab in some places, and filling it in in other places.
3) Ignore them, and build any place you need to, but losing the advantage of the decoupling.

But first, there's a question: Did you leave a gap ONLY between the LR and CR? Or did you also leave gaps all around the edges of both slabs, such that they do not touch the walls? In other words, are your walls resting on a separate foundation from the slabs?

I was also trying to minimize flutter reflections, possibly out of a lack of real knowledge?

Flutter echo is fairly simple to deal with, using basic absorption panels at strategic locations, or diffusion in some cases. And since you will need that anyway, there's no need to splay the walls as well. The only real reason for splaying walls is if you want to build an RFZ-style studio, or one of the similar types, where the room shape itself is used to direct sound away from the mix position. Or you might just want to do it because it looks good!


- Stuart -

[ward]

Thanks Stuart,

Hmmmm... that's a problem! It means that you are locked into those shapes and dimensions now.

yes.

You have three options:
1) Use them as they are, with the CR shape not being optimal.
2) Modify them by cutting the slab in some places, and filling it in in other places.
3) Ignore them, and build any place you need to, but losing the advantage of the decoupling.

I'll have to check for option 2 if I can find someone to cut it.
It's about 20cm. I can't do that myself.

Or just go for option 3, I don't know how much of a disadvantage this is.

But first, there's a question: Did you leave a gap ONLY between the LR and CR? Or did you also leave gaps all around the edges of both slabs, such that they do not touch the walls? In other words, are your walls resting on a separate foundation from the slabs?

The walls are more or less separate from the floor.
I'll try to explain:
On each long side of the rectangular there are 5 steel beams that support the concrete ceiling.
These steel beams are standing on poured blocks of concrete, about 80x80x800cm, that extend under the walls.
That's about all the foundation that the walls have.
On top of that is the concrete floor
I checked this with a stability engineer.
So the floor and walls connect at ten 80x80cm points where these concrete blocks have been poured.

Flutter echo is fairly simple to deal with, using basic absorption panels at strategic locations, or diffusion in some cases. And since you will need that anyway, there's no need to splay the walls as well. The only real reason for splaying walls is if you want to build an RFZ-style studio, or one of the similar types, where the room shape itself is used to direct sound away from the mix position. Or you might just want to do it because it looks good!

I believe someone told me that for a good RFZ design my ceiling height is way too small.
Going for what I planned, the diamond shape, wastes space in the corners as I have read here.

[Soundman2020]

Or just go for option 3, I don't know how much of a disadvantage this is.

That depends on how much isolation you need. If it is typical levels for project studios, then it is not an issue. If you need very high levels of isolation, then it would be worthwhile to have decoupled slabs.

So the floor and walls connect at ten 80x80cm points where these concrete blocks have been poured.

Then your slab is not decoupled!!!! So there's no difference in isolation.

I believe someone told me that for a good RFZ design my ceiling height is way too small.

Not true! Whoever said that does not have a good understanding of RFZ. You have 3.5m!!!!! That's PLENTY. I have designed RFZ-style rooms where the available height was a bit less than 2.2m... It's not easy at all, but it can be done.

Going for what I planned, the diamond shape, wastes space in the corners as I have read here.

Yes. Correct.

- Stuart -

[ward]

Thanks Stuart,

So, I'm ready to ditch the diamond shape,
seeing that the coupling in the floor/wall is impossible to resolve on the cheap and probably not that big of a problem.
BTW, budget is still small/too small, so think project studio, not professional with very high isolation level.

I'll have to make a new sketchup file and photos of where I am right now.
(the drawings in the beginning of page two are outdated and wrong.)
And a new division of the space with good room ratio.
There's only about 2.9m height left under the concrete ceiling.

[Soundman2020]

There's only about 2.9m height left under the concrete ceiling.

That's still plenty. Not a problem.

- Stuart -

[ward]

OK, a new drawing to make things clearer.


I was experimenting with dividing the space into control room and live room.
Total space before placing the inner walls is 6m width, 10m length, 2m90 height.

I started looking at modal behaviour of the control room, the smallest space on the left.
With the amroc calculator :
For a height of 2m75, and a length 5m20, things start getting reasonable at a width of 4m25
Bolt checks out ok, Bonello ok.

Problems arise with the live room, I'm left with a space of H2m75, L5m20 and W5m70
Bolt -, Bonello -.

Bob Golds calculator tells me about the same, ok control room, the live room is not good.

Any suggestions how to find the best compromise ?