Building a studio into a hillside. What shape should it be?

[Deathvalleydog]

That's the plan.

I've got an area roughly 22 ft in diameter to work with, and about 23rds of it will be dug into a hillside and ultimately covered up with a living roof. Think "Hobbit House" without the round door. Probably around 3500 cf of volume (depending on the height/angle of the roof) with no plans for a separate control room at this time ... just a place to play and record in that sounds nice and is acoustically neutral. The roof/ceiling shape/angle can also be whatever, as long as it isn't so steep that plants wouldn't be able to grow on the top.

My question: what shape should I make it? Obviously parallel surfaces are bad, so I was thinking of a wonky pentagram? Or maybe a seven-sided shape?

Whadayathink? What shape would YOU make a 3500 cf sound studio if it could be anything you wanted? And why?

 

[RFR]

I have no idea how you would design it, but it sounds cool to me. I think you should go for a round door.

 

[Tadpui]

Anything but a cube.

Having any 2 (or more) dimensions the same length/height would be the next worst. Next worst would be having any 2 (or more) dimensions being multiples of each other. A big rectangle with a ceiling of 8 or more feet would be great, as long as you plan on putting a good amount of broadband absorption in it. I think at least 2500 cubic feet would be a great start. If you have the freedom of room shape, then slightly sloping the walls away from each other and sloping the ceiling relative to the floor would be a good idea. Check out a book or two on the subject for more specific suggestions (have a google for Gervais' "Home Recording Studio: Build It Like the Pros" as an example).

 

[Deathvalleydog]

Oh yeah, I have that book ... it's a great resource

I've just got such a unique opportunity here, I'm curious if anyone has some thoughts on cool/weird acoustically friendly ideas for the shape of the Hobbit House studio.

 

[mjbphotos]

Anything but a cube.

Or a round room, or a multi-sided but basically round room (think naturally occurring echo/resonant chamber).

 

[Deathvalleydog]

Or a round room, or a multi-sided but basically round room (think naturally occurring echo/resonant chamber).

That being the case, what do you think of pentagon vs heptagon? And in both instances all the inner angles and wall lengths would be different. Here's a seven-sided one I've been playing with.

 

[miroslav]

Well...I would think you want some symmetry, especially of you are also mixing in there...
...but try and avoid absolutely parallel walls if you can, though it hasn't been a problem for the thousands of studios that have parallel walls.

I like the Hobbit thing into the hillside, and the round door......but I don't think I would want some twisted hexagonal/octagonal shape or whatever, for a studio or a living space....YMMV.

Look at 99% of pro studios....they look like, well....your typical 4-sided rooms.
Small wall angle/size difference are enough.

 

[Deathvalleydog]

Look at 99% of pro studios....they look like, well....your typical 4-sided rooms.
Small wall angle/size difference are enough.

Very true. But a couple of things have me leaning towards the weird shape.

First off, if it's truly going to be inspired by a Hobbit House it just seems wrong to NOT have an unusual shape, ya know?

Another thing is the contours of the hillside itself: If I don't have to dig into the upper left (11 o'clockish) section it saves me having to re-route some underground utilities, hence that longest wall of the 7-sided figure.

But the biggest reason is that I suspect there will be just as much playing in this studio as actual recording, and I think the open corners (greater than 90 degrees) lend themselves to a nice "jam space" where musicians (and equipment) can be gathered around the center.

All that being said, is there any reason the wacky shape WOULDN'T work from an acoustical standpoint?

 

[gecko zzed]

All that being said, is there any reason the wacky shape WOULDN'T work from an acoustical standpoint?

You could probably get it to work, but it would be difficult. I would aim for wackiness that has one axis of symmetry, so that when you set up your mixing area, your stereo field is going to be affected the same left as it is right. Having to cope with a different set of reflections from one side of the room to the other would be tricky.

 

[Chili]

Half circle on one end, straight wall on the other. Ceiling slopes down from half circle to straight wall. Record and mix in the same room. Mix station nearer the straight wall side with monitors facing out to the half circle.

 

[Deathvalleydog]

Half circle on one end, straight wall on the other. Ceiling slopes down from half circle to straight wall. Record and mix in the same room. Mix station nearer the straight wall side with monitors facing out to the half circle.

Interesting.

Could you elaborate on how/why this works? And what about the walls connecting the half-circle wall to the straight wall? Also: I thought round was bad, as it creates an echo chamber. (and please, pardon my ignorance on all this )

I don't suppose you could post a rough sketch

 

[Chili]

I could try to post a drawing. I saw this in a court room one time and thought it was really interesting. And dang if it didn't work. The judge sat in the focal point of the half circle. I sat in the middle of the pews so the DA couldn't see me, I could hear the judge with no problem and no echo or reverb. It was a great room, acoustically. Not so much for other reasons, but that's why we pay lawyers the big bucks.

I figure if you're carving into a hillside, you can have any shape you want 3-dimensionally. You will probably still need room treatment.

 

[mjbphotos]

I'd avoid too many corners - each one should have a full bass trap/superchunk in it. A half circle concave will concnetrate reflections to one spot, but on the other hand, a convex (into the room) curve will act as a diffusor.

 

[Deathvalleydog]

I could try to post a drawing. I saw this in a court room one time and thought it was really interesting. And dang if it didn't work. The judge sat in the focal point of the half circle. I sat in the middle of the pews so the DA couldn't see me, I could hear the judge with no problem and no echo or reverb. It was a great room, acoustically. Not so much for other reasons, but that's why we pay lawyers the big bucks.

I figure if you're carving into a hillside, you can have any shape you want 3-dimensionally. You will probably still need room treatment.

Oh yeah, like a parabolic dish. I remember a pair of those at a science museum that faced each other, and you could whisper at one and the person 50 feet away at other could hear you with no problem.

 

[Deathvalleydog]

I'd avoid too many corners - each one should have a full bass trap/superchunk in it.

As the angle of the corner gets wider, how does that effect the need for a bass trap? I imagine at a certain point it becomes moot, yes?

 

[mjbphotos]

As the angle of the corner gets wider, how does that effect the need for a bass trap? I imagine at a certain point it becomes moot, yes?

Draw the wave diagram like you did with the concave wall- remember that the angles to and from a flat wall will be the same. The problem with the convex wall idea - its great for hearing something spoken/created at that focal point (like a courtroom), but how do you use it when recording?

 

[Chili]

Oh yeah, like a parabolic dish. I remember a pair of those at a science museum that faced each other, and you could whisper at one and the person 50 feet away at other could hear you with no problem.

View attachment 95631

Maybe something more of a true half circle rather than a parabola. Maybe the sound energy would get 'trapped' in the half circle because most incident angles bounce back into the circle. But I haven't done any math, nor will I. More of a gut feel and an interesting experiment if you could actually carve it out in 3d.

Walls leading from straight wall to half circle wall would expand out a little, just like the ceiling.

I guess my court room utilized a parabola to project sound out to the room. Maybe that's not a good idea in a mixing situation, but might be nice for a live room. IDK, throwing ideas out and see what sticks. lol

But definitely, the oddball shape you posted up earlier wouldn't work very well. You've got have some symmetry for a good stereo image.

 

[Deathvalleydog]

OK, so here is a pentagon(ish) idea, with one axis of symmetry.

It's a bit less "wacky" than my original vision, but it's occurred to me that nothing is preventing me from constructing an outer skin that doesn't follow the exact same dimensions/angles of the inner walls ... in fact, it would be better for sound insulation.

That way I can have a functional recording (and mixing) space, while from the outside it can look like a Hobbit with ADD lives there



whadayathink?

 

[RFR]

Looks good to me, but you still need a round door.

 

[miroslav]

First off, if it's truly going to be inspired by a Hobbit House it just seems wrong to NOT have an unusual shape, ya know?

Actually, if you look at the Hobbit houses (at least from what's seen in the Hobbit movies)...as odd as they are compared to conventional houses, there is still absolute symmetry inside.

Look...amuse yourself, do what you think is best...but I suggest you ask some guys who actually build real studios, and/or do some research rather than just making assumptions about what you think "should work"...etc.
Once it's built...if it's all wrong, it will be a major PITA to correct.

I'm just saying that if I was going to build a studio from scratch, the last thing I would do is make up my own rules about what right and wrong.