Cloud: 6" gap to play with. How?

[The Digital Owl]

Hello there,

I have come to the point of putting a cloud in my studio. It is currently a live room and control room in same room. The cloud must at least cater for my first reflection above me between speakers and my ears. The cloud must also cater for the live area - maybe drums recorded here, definitely vocals and acoustic instruments.

I have a raised stage (live area) which actually has lots of insulation inside it (with a few little holes of 3 different diameters drilled through sides to let some sound in). If I put a cloud too low it shall be claustraphobic to be underneath of. The ceiling is roughly 8ft high, the stage is 10" high. I have 4" Knauf RS60 insulation slabs that I was going to use. I have 1" x 1 & 1/2" room width pieces of wood spaced evenly along opposing walls. The RS60 was going to go ontop of these (room width) long pieces of wood as my cloud. I want to cover as much of the ceiling as possible if not all. I want it to be as comfortable as possible under cloud on stage live area so the highest I can go is to the bottom of the coving I have which gives me 6 inches gap above wood. To go lower i.e. 8" from ceiling (4" insulation with 4" gap) is claustraphobic so is out of the question really.

So with my 6" this would mean if I used 4" insulation I'd have only a 2" air gap which is not good right? Would I be better off getting 3" insulation slabs to leave 3" air gap instead? Or even getting 2" insulation leaving 4" air gap. Whichever way you look at it I have 6" gap to fill or part fill. What is the best way to do this?

Is RS60 not right for clouds anyway, should I be looking at different density like RS45 or even loft fluffy pink stuff? Or a mad combination of all? I would like to use the RS60 for panels I'm going to make instead so it shall not be wasted. More insulation will need to be bought whether you guys think it should be more RS60 or something else anyway.


Kind Regards,

The Digital Owl.

[gainstages]

i don't know that there is only 1 absolute answer here - acoustics is a science, but the application of that science is still based on preference, opinion, comfort, cosmetics, etc.

I like that you are thinking of an air gap - too many people just stick up some foam or a panel right on the ceiling. I personally like to include the air gap between ceiling and cloud, and maximize that as much as possible. what is actually sonically best for your room should take into account the rest of the room treatment. I have in the past used a general rule of thumb that i like having the treatment and the airgap be the same, so 3" of treatment suspended 3" off the ceiling. is that a magic formula or technically perfect response...no but you asked for opinions, and that is mine!

personally, i would start by questionning why you have the stage in a room where ceiling height is so limited to begin with...? maybe a thin riser to help isolate and decouple, but it sounds like yours may be a little extreme.

[The Digital Owl]

Hey Gainstages,

Cheers for the response. I admit that the 3" insulation with 3" air gap has taken my fancy the most, but am open to change if clouds are better off with a different treatment like pink fluffy loft stuff or thinner less dense slabs etc.

As for the 'oversized stage' the guitarist from my old band was a carpenter who said he was making a 'drum riser' for our drummer for when we rehearsed in this room. He even assembled it when I wasn't there. I didn't see it till it was built. It was a great token from him. Now the room is for recording only (so I need a cloud) and I thought I'd keep the stage there as 'it makes one feel rather important when on it' and I thought this might help get good takes as standing on it automatically makes you perform with confidence - its a stage after all

Has anyone else got opinions on the best use of the 6" air gap?

Kind Regards,

The Digital Owl

[DanDan]

See Q4Avare.
Six inches of fluffy insulation would probably be best.
4 inches of RS60 with a 2 inch gap would be next best.
And so on.

The stage, hmmm. Sounds like a big bass trap. Might be doing a good job on the vertical mode or maybe not.
I do know from experience and as a drummer that such platforms suck all the bottom end out of the kit. On a concrete floor is best for LF.
DD

[The Digital Owl]

Hey DanDan,

Cheers for chiming in, your advice has helped me in other threads (including my own).

See Q4Avare.
Six inches of fluffy insulation would probably be best.
4 inches of RS60 with a 2 inch gap would be next best.
And so on.

I am reading the 'Q4 Avare' thread you pointed me to. Woh, hard reading! Haven't finished reading it yet but so far it seems smaller with a bigger gap was winning the opinion. Maybe as I get further through the thread, it will become clear why you chose the 6" fluffy insulation (which would completely fill the 6" gap - no air gap at all) or the 4" with 2" gap next. As it seemed the bigger the air gap the better 2.2:1 ratio taking as low as 54Hz I think it was? So the 2" insulation with 4" air gap should win maybe?

As I say I'll continue reading that thread and probably discover why 6" no air gap wins your vote.

The stage, hmmm. Sounds like a big bass trap. Might be doing a good job on the vertical mode or maybe not.

Measurement Testing would of course tell me the answer to this but I have not gotten round to mastering that yet! tutt

I do know from experience and as a drummer that such platforms suck all the bottom end out of the kit. On a concrete floor is best for LF.

So being a drummer you've found this. This is very interesting. For recording live drums then, if I were to use this room, I would be better off not using the stage and instead the floor besides it. I have a completely carpeted floor but half the room is concrete, half wooden (both halves underneath carpet). Would I be best off putting some wooden (plywood?) boards under the kit ontop of the carpeted concrete half?

Would the stage/big basstrap suck the bottom end out the kit as it's within a close-ish proximity to the kit? In other words would the stage be affecting the kit (and room) so much that I'd be best off not using this room for drums at all in your opnion?

Cheers for the help.

Kind Regards,

The Digital Owl.

[DanDan]

Platforms are not as dense as concrete, so they will not act as an LF boundary.
Such a boundary pretty much doubles the Bass, particularly of course in the the Kick and the Toms. Plywood is often used to avoid that carpet sound.
Drums get another LF lift near solid walls. Near two solid walls, i.e. a corner, another LF lift. Same as loudspeakers.

I am just guessing the 6 inches would be best.
If you had the Gas Flow figures for the various fibre options you could calculate the optimum.

Here's a brilliant online porous absorption calculator.
Porous Absorber Calculator

I am just about to start a new thread to collect common Gas Flow Resistivities.
DD

[The Digital Owl]

Hey DanDan,

Cheers for the info. A quick google for the gas flow figures of Knauf comes up with Max Dread asking gearslutz for any help with this too, as Knauf don't have any figures for ANY of their products let alone the important RS60 we both would like to know. He has been on the phone to Knauf and other manufacturers who have haven't really helped him much.

So have I got you right, you are saying it would be best to placce the drums NOT on the stage but in the corner on plywood boards on the concrete part of the room? This would avoid the LF being sucked out by the stage.

The stage (LF suck) would probably be good for sources where a high pass filter would be used later on though, yes? Such as vocals and acoustic instruments?

Kind Regards,

The Digital Owl

[DanDan]

That's about it although corner boost may be OTT.
I noticed the other day that Kick drums interact with room modes in a directional manner. e.g. My kick, centre of room in the length null, facing lenghtwise, a petty thin clicky thing.
90 degrees perpendicular to the mode/null, nice and subby.
Quite a spectacular difference.
I don't think the stage is useful for vocals either! Voice hasn't much bass and the height will move the singer closer to the ceiling.
DD

[The Digital Owl]

That's about it although corner boost may be OTT.
I noticed the other day that Kick drums interact with room modes in a directional manner. e.g. My kick, centre of room in the length null, facing lenghtwise, a petty thin clicky thing.
90 degrees perpendicular to the mode/null, nice and subby.
Quite a spectacular difference.

Interesting, I suppose the technique where you take a tom in one hand and hit it as you walk around and listen to find the sweet spot where the drums sound biggest, may well fit into the perpendicular to mode/null finding you have. That may well be the explanation for the best live sweet spot!

I don't think the stage is useful for vocals either! Voice hasn't much bass and the height will move the singer closer to the ceiling.

Oh man! Something I didn't want to hear. So I have it wrong that getting a dry as possible sound for vocals is desired then? The closer vocalist would be to the cloud I thought would be best, with back to a superchunk, and absorbers to the sides, maybe even one infront of the mic. Wouldn't this kill relections coming into the mic from nearby walls & ceiling be a good thing?

What would be good on the stage then? Just acoustic instruments? Guitar Cabs, Bass Cabs?

Or (gulp) nothing would be good on the stage?

Kind Regards,

The Digital Owl

[DanDan]

Sorry Dig. Redirect if the Cloud above the vocalist is decent, then you should be fine. Dry or at least lack of very early reflections is good for vocal. Anything close by needs to be suppressed, including the floor.
DD