duplicate

terrible_buddhist · Post by **terrible_buddhist** » Tue Apr 27, 2004 3:37 am

this is also over that the design forum, but there are a couple questions which may be better answered here...like the ceiling one:

As always during construction, I have run into some issues...attached is the new mark up of my control room. Here are my questions:

1) Are the angles on the speakers going to be ok, they are equal, but sharper than I had originally hoped.

2) the angled walls, which I imagine will actually be slat absorbers (please correct me if I am wrong) will only be at their deepest a foot, and 52 inches long.

3) My celing height as of now, with NO drywall (framing only) is 80 inches. I can't go any higher than this because of a steel beam that runs across the top which I don't want the ceiling to touch...this is a floated room. So, do I:

a: put 2 angles in the ceiling, starting at the window and going up, and at the rear door going up, creating a peak in the room with no absorbtion on the ceiling.
b: go for a flat celing and try to put much absorbtion on it.
c: anything you can think of as really, I am stumped! Remember, I also have door height to worry about. YIKES, what a pickle!

Please help.

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rod gervais · Post by **rod gervais** » Tue Apr 27, 2004 5:18 am

terrible_buddhist,

the first thing that has to happen here is for you to fix your dimensions for the speaker placement and listener position.

The dimensions you indicate cannot be correct - for it is impossible for them to meet.

a dimension of 39 1/2" from face of speaker cabinet to listener position - and then 42" to the meeting point (with matching triangles) creates a space between the 2 points of 2'-4 9/16" - yet you indicate more than 4' between the speakers themselves. The 2 dimensions you indicate would force this - each speker would splay at 70 degrees from the window face - and would meet at a 40 degree splay at the listener.

If you held the 4' (the window edges) as the centerline of the speakers - and the same 39 1/2" you would have dimensions of 46 1/4" for the remaining angle.

So let's begin there.

Give us the centerliine of the speakers in relation to one another - and then the dimension from those centerline points to the meeting point at the listening position.

One observation (just based on the graphic - if i accept the scale as fairly accurate) - the listening position should shift further back into the room.

You really want an equalteral triangle for the listener - 60 degree angles is fairly common in this respect - that for proper stereo iimaging.

It looks to me as if you are much too close to the front wall.

Rod

knightfly · Post by **knightfly** » Tue Apr 27, 2004 5:36 am

Thanks Rod - Keith, who's running the tape measure in your project? sounds like someone needs to RTFM (Read The F---ing Manual)

If nothing else, get a roll of 3/4" masking tape and tape out your floor plan, using a point just BEHIND your head as the third point of your equilateral triangle - then, measure again... Steve

terrible_buddhist · Post by **terrible_buddhist** » Tue Apr 27, 2004 5:38 am

my problem here seems to be, if I change the angle of the speakers in the other direction, my splayed walls then become even shallower. is there a work around here?

The drawing is definatly not to scale, the listener position was an approximation based on the angle we thought the speakers would have to be at.

Also, I still really need ceiling solutions as this is going to be the next step in the building process.

terrible_buddhist · Post by **terrible_buddhist** » Tue Apr 27, 2004 5:43 am

oh, also, the only thing BUILT right now is the outer framing, door frames and the window frames...everything else is negotiable

knightfly · Post by **knightfly** » Tue Apr 27, 2004 10:02 pm

Kieth, right now your MAIN problem is that you're oonfusing things with your 'WAY out of scale drawing - you need to address that, get a proper mix triangle (your numbers are IMPOSSIBLE and your drawing doesn't help) - your ceiling is so low, I don't think it's wise to slope it. Just hang a cloud with a couple inches air space behind it directly over the desk (once you get the desk where it belongs) and hope you don't have anyone in there that's over 6 feet tall...

Please re-think what you're doing before you continue, you've come too far to screw it up now by getting antsy - re-measure, re-draw, and post your results and we can go from there... Steve

terrible_buddhist · Post by **terrible_buddhist** » Wed Apr 28, 2004 12:08 am

I am going to go over and redo my measurements as well as have a better representation of what is going on in the drawing in a few minutes...

Can some one direct me to a good link for cloud construction?

terrible_buddhist · Post by **terrible_buddhist** » Wed Apr 28, 2004 12:09 am

never mind on the cloud thing...just found a link...thanks.

terrible_buddhist · Post by **terrible_buddhist** » Wed Apr 28, 2004 2:13 am

since it looks like I am going to need to redesign the room, I have posted my measurments in the design forum...any help is always appreciated.

terrible_buddhist · Post by **terrible_buddhist** » Wed Apr 28, 2004 11:08 pm

knight,

should I do a drywall ceiling, then do a cloud? Or should I do an insulation/ fabric ceilng (nervous about isolation with this method) and then do a cloud?

knightfly · Post by **knightfly** » Thu Apr 29, 2004 1:12 pm

Remind me again what's already there? Is the existing ceiling solid concrete, or what? As much detail as you can give... Steve

terrible_buddhist · Post by **terrible_buddhist** » Thu Apr 29, 2004 11:32 pm

well...if I were laying on the floor of the control room,

I have 2 x 4 cross beams (this room is completely on its own, floor floated, and then we built the walls on top of it, with cross beams joining the walls.) The bottom of the cross beam to the floor is 80 inches.

above the cross beams on the left hand side of the room is a Steel I Beam that runs the length of the entire building. This steel beam is approx 1/2 inch above the cross beams...but due to settling over the past 70 years or so, this could cary across the length.

This steel I beam is of course holding up the concrete ceiling which is common to the entire area.

This room needs to be completely sealed from the rest of the studio because there are air lines running along the ceiling which go through the drywall of the main tracking room, as much as I plan on sealing around these, I want to make sure I have this room isolated all on its own.

Is this detailed enough? If not I can take some pictures...what ever will make your life easier, and me get the results I need.

knightfly · Post by **knightfly** » Fri Apr 30, 2004 3:41 am

How far apart are the new ceiling joists (2x4's)? If they are on 16" centers, and running the SHORT way, you're fine for two layers of drywall with insulation over the top. If you've done them on 24" centers, you're barely good for a 5 pound per square foot dead load (weight of all materials including framing); subtracting 1 PSF for framing, that leaves 4 PSF for ALL paneling - 5/8 wallboard runs around 75 pounds per 4x8 sheet, divide by 32 to get weight PSF and you get 2.35 PSF per layer of 5/8 drywall. Two layers plus framing puts you OVER the 5 PSF limit if your joists are on 24" centers.

Bottom line - if you're using 24" centers, one layer of drywall is all you should put up for safety. One way around that without removing anything, would be to put joists between each pair (gives 12" centers) - this would increase your max span for 2 layers of drywall up to 9'10" -

Let me know what you have for spans (please tell me the joists are running the SHORT way) and center to center distances... Steve

terrible_buddhist · Post by **terrible_buddhist** » Fri Apr 30, 2004 5:04 am

they are running the short way...I am not sure I can get the drywall ABOVE the cross beams though...space is at a super premium up there

or are you saying fill the joists with insulation...then 2 layers of drywall...then a cloud?

knightfly · Post by **knightfly** » Fri Apr 30, 2004 8:10 am

The drywall would go BELOW the joists - your existing concrete above that is your outer leaf of a mass-air-mass system.

Now, how far apart are your 2x4 joists? If they're on 24" centers, you should put a MAXIMUM of one layer 5/8, one layer 1/2" on them. If they're on 16" centers, you can use two layers of 5/8 no problem.

Your last scenario is the correct one - "or are you saying fill the joists with insulation...then 2 layers of drywall...then a cloud" -

Please don't overload your joists; even if you're into Death Metal, death by drywall is MUCH less fun... Steve