John Sayers' Recording Studio Design Forum Archive

hello

I am going to be building my studio in my walkout basement. My plan is
to float the floor and build "room within a room". I will have a seperate
control room and studio each floated on there own floors. The problem is that there is a structural wall (2x6 timber) inbetween where my control
room and studio meet. This is where I would have to put a window. Should I frame an opening in this wall and place the glass in the floated
walls, or should I tie this wall in with either the control room wall or studio
wall? If I float the rooms on either side and face my studs towards it, there would be about 14 inches between the panes of glass and this wall
in the center. Is that ok or should I insulate it and sheetrock it and the
face my studs from the studio space towards it? I hope this is makeing
sense!

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Here is a crappy diagram to help explain.
e=existing 2x6 stud wall.

Any help would be appreciated

Thanks
jdf

If you're NOT on a Mac, could you do a basic drawing in Paint? These "XOX" attempts at graphics just don't convey enough to someone who didn't draw them -

Basically, you want only two leaves of mass in a wall system between any two areas you're trying to isolate - if the existing wall is clad both sides, you could remove the paneling on one side, add to the paneling on the other side, and build a second frame with paneling only on one side. Then, your construction would be wallboard layers, 2x6 frame, insulation, 2x4 frame, wallboard layers - you can build a header into the existing frame, match it with the new frame, and put your heavier glass into the 2x6 frame (along with probably a third layer of wallboard) - this will give the best isolation... Steve

There's a couple things you could do...

First, are you certain you'll need to float both control and tracking? I mean, for my purposes, I don't track all that loud that I need to keep from disturbing my neighbors when I'm mixing... it's the tracking room that needs isolation for the big Marshall stacks and heavy-hitting drummers. So you could conceivably float the tracking room, and just build the control room normally.

Or, if you do need to have them both floated (so you can mix at 2:00am in a room right beneath the bedroom where your kids are sleeping, or something like that) you could remove ALL the paneling from the structural wall (chances are it doesn't need paneling) and just ignore it from an acoustics standpoint. Frame up the walls for tracking and control on either side of it, and sound will pretend it doesn't existing (you'll have a nice wide space between the 2 acoustic walls, too!). You may or may not want to insulate it, just to cut down on reverberation between the walls, but that's up to you- if you're insulating between the studs on both the acoustic walls, and need to cut a corner somewhere, you'd be ok leaving the studs open.

If your structural wall needs sheathing or bracing of some kind, you can use steel strapping at an angle across the face of the studs (probably on both sides). That'd stiffen the wall without closing it off.

As far as the window goes, yeah, just frame the rough opening in the structural wall and put the glass panes in the acoustic walls on either side.

Hope this helps!

thanks for the replies.

knightfly
Unfortunately I am on a Mac. that is why my pic did not come out so well. there is no wall board at all on the 2x6 frame. Just bare timber.
Should i put that on the side of the control room so the insulation and
open studs face the studio wall?

dymaxian
I need to float the studio because I will have drums in there and I dont
want to upset the neighbors. So the actual studio will have floated floor
walls and ceiling(room within a room).

As for the control room, I need to float at least the floor because there
are pipes roughed in for a future bathroom that are sticking through the
concrete. I need the space so there wont be a bathroom there but it
would be a nice selling feature to have when and if we sell the home. So
I thought I could leave them and go over with a floating floor.

Thanks for the replies
Keep em coming

jdf

Gotta get some sacktime, but check this page out - especially the bottom diagram. This shows exactly what goes where for best results - note that in some cases, the EXACT same amount of material can result in a difference of 23 dB loss, just depending on what goes where -

http://www.customaudio.freeserve.co.uk/ ... /tloss.htm

Also, check the "complete section" sticky for more info on wall construction... Steve

thanks knightfly

one other qustion. do both walls need to be floated? for example, if doing a room within a room design only the one wall is on top of the floated floor? right? The other wall is attached to the concrete floor.
Or does it even matter?

thanks
jdf

If you're still talking about the double wall between CR and live room, yes - floating either wall will help isolation between the rooms; if the CR floor is floated, float that side of the wall on the CR floor; if the Live Room will be floated instead, then float that wall frame instead. Only if both rooms are floated for max isolation between each other AND the outside world, would you need to flloat both frames of the CR/live room wall... Steve

My recommendation is to float all the walls in both rooms. If you're going to need lots of isolation in the tracking room, and you've got pipes coming up in the floor under control (which will make noise when water flows thru 'em), go ahead and float everything. If you have the budget available, it's better to err on the side of caution. If you keep your doors and windows sealed tight, you should have a nice quiet space- or a nice loud space without getting visits from the police.

The only other thing to think about is whether you need to float the tracking and control rooms separately from each other- do you need that much isolation between the rooms? If you're floating them both anyway, it's really not all that much more of a headache to float them separately.

i do plan on floating the room seperately. Since I will be building in existing rooms that have walls attached to the concrete, does that matter? Or should I put 2 new walls on top of the floating floor? Opposite facing and drywalled on one side, or is it ok that the external
walls are attached at the existing concrete floor?

thanks guys

I agree with Kase; floating everything is best if you can, and separately is best of best. As to your other question, the one rule you do NOT want to violate is this: between each space you want isolated and the source of sound you don't want to hear, you want two and ONLY two centers of mass, separated by an air space. Air space is the total distance from the inner surface of one of your centers of mass to the inner surface of the other center of mass. Studs are not figured into this, although they will hurt performance slightly; moreso if there are too many of them (which further subtracts from the air gap) -

This is how to determine if your design will be the best it can be - imagine yourself as a sound, and you're starting from outside on the street - try to get into one of your rooms; if you go through any number of layers of solid, hermetically sealed building material, that's ONE leaf of the wall - if you then have to travel through a non-hermetic space (such as air or insulation that's NOT closed cell) and then a second solid leaf (such as 2-3 layers of gypsum, which counts as ONE leaf) - at this point, you (or what's left of you after your ordeal) should now be inside the area where you're NOT WANTED.

Sound >mass >air >mass > quiet place. No more, no less. Look at the graphic at the bottom of this page

http://www.customaudio.freeserve.co.uk/ ... /tloss.htm

the examples labeled STC 33,36,57 and 63 are all varying degrees of the RIGHT way to build for best isolation. All the others are flawed, and while they may slightly improve on midrange isolation they will be pretty crappy for low frequencies such as bass and drums.

This same mass-air-mass rule applies equally to floors and ceilings, as well as doors and windows. Once you master this concept, you're well on your way to designing your own sound isolation using ANY material to its best advantage.

Keep in mind that when figuring all this out, you must include ANY barrier that's not ventilated in some way - if it's a solid barrier, it counts toward your two centers of mass (leaves, in acoustic terms) so, if you have a concrete wall between you and the world, you could glue more layers of wallboard onto the concrete without making it a double leaf (not practical unless you have no room for a second frame) or just leave it, frame out and insulate, and put up 2-3 layers of drywall (for example) and you're DONE. If you were to build a studio inside a concrete bunker, for example, and it consisted of a CR and a live room, each of those rooms should be on separate floated floors (this completes the mass-air-mass for the floors) - then, a frame with wallboard on only one side would go around each room, floated on its respective floor - this would complete your m-a-m barrier for walls. Then, if your ceiling has adequate mass above its joists, that's ONE of your two leaves for ceiling isolation - adding a ceiling frame resting on your floated walls and a hermetically sealed 2 or 3 layer drywall leaf on ONE side of this new ceiling frame, properly caulking everything as you go, would finish your total mass-air-mass barrier between each room and the other, as well as between each room and the outside world.

Hope that helped... Steve

thanks steve

also should both walls have insulation. I have seen examples of only one
side insulated and I have seen examples of both sides insulated. Does it
matter as long as there is and air gap between the two spaces

thanks

The more insulation the better, as long as it isn't crammed in tight enough to cause relatively hard coupling between panels on opposite sides of the wall - light to medium contact is OK, in fact a certain amount of contact helps dampen the wall panels and improve performance by a few dB. Optimum insulation density for sound walls is around 2 to 3 PCF - lighter helps bass isolation, heavier helps high frequency isolation more - just the opposite of what you'd expect... Steve

thanks steve should i compress a higher r value insulation into the studs then? for example 2x4s generally use a R11. Should I get R19 and
compress it into the 2x4 space? and if so what is a good way to go about this since there is only drywall on one side to hold it in place?

No, if you're planning on using normal house insulation (don't use foam insulation, it's closed cell and worthless for sound) probably the best way (for a single framed wall, that is) is to just install the normal R-11 stuff - then, if you cut patches from a batt which are around 8-12 inches square and glue them to the face of the full insulation, centered between studs and spaced unevenly in the vertical dimension, varying between 1 to maybe 3 feet apart, they will provide damping for the panels without too much compression; you should be able to fasten the wall panels over those without too much effort.

For your double framed wall with panels ONLY on the outer side of each frame, the first thing I'd do is to frame so that your studs are NOT in line from frame to frame - if the studs of one frame start 1 foot from the intersecting wall, start the stud on the other frame at 2 feet, so there are no studs (except for window frame area) which are directly across from each other.

This allows you to use thicker insulation, the insulation only being compressed much where there is a stud behind it (opposite the insulated cavity)

Here's an example of what I mean -

steve

does it make a difference if i use batt insulation or kraft faced? If kraft faced is ok, is it ok to staple to the wood studs?

thanks
jdf