John Sayers' Recording Studio Design Forum

Hey I'm new here, but this is already one of my favorite forums.
Especially since I will be moving my studio to a new place.
The new space does have a few issues that need to be worked out, so for this I was hoping to get some advice.

The space is situated in a basement and is on one side adjacent to the public road (Wall C in Sketchup), one side is a club (Wall B), one is some storage room (Wall E) and behind wall A and above the studio are empty spaces that are not used at the moment but might be in the future. There are some pipes (heating and rain drain) that run through the space (see pics below). I am 2 meter tall so the beams are a bit low (1,96m, I will need some foam for that ). At the moment there is a wooden wall underneath beam B, but that will be removed as soon as I start construction. There is no sanitary facility so I need to build that too.

The studio will be used for both production and mixing. My music generally has quite a lot of low-end frequencies. I have quite a heavy subwoofer for that (Klein+Hummel O810 with a pair of O300). So I need all the isolation I can get. Since two walls are very thick (Wall B and C) and one is in between my studio and some storage place (which is also much ticker than other walls in the Basement (I believe around 20cm or 8" solid concrete), I only need to worry for one side of the studio (for the walls part). I'm planning to build concrete/sand walls with some air in between (mass-air-mass). I was thinking about 15cm/6" concrete sand, 15cm/6" air (with some rockwool) and 15cm/6" concrete/sand again. But are there any ratio's that work really well? I also understand that sand also has an extra dampening effect compared to solid concrete. Is this correct and how much does it differ?

The floor is pretty thick and since it is the basement I think it is on the ground, but there is no way to check so it might be the case that the ground is lowered in all these years (which is not unlikely here in Holland). But I don't really think I would need a decoupled floor. The ceiling is a different story. It is only 10cm/4" of concrete. So some isolation to the upper floor is necessary. Are there any solutions that are efficient at low frequencies? Will the beams and pillars be a problem in transferring sound or might it be that they are under too much pressure or are to thick?

There are also some heating pipes running through the space (see pics). I also need to construct two heating modules on them (one in the recoding room and one in the mixing room). Are there any solutions that won't transmit too much sound the rest of the heating system? What is the best solution for isolating the pipes (other than rockwool)?

Since I'm working with all kinds of musicians I also need some recording space. So I will also divide the space into two with a double concrete/sand (m-a-m) wall. In this wall I want to build a sliding glass door, but I'm still not sure how I should do it (buy it second hand or build it myself). Are there any comments on constructing sliding doors and how effective they are?

There are also 3 air vents (simple holes) in wall C, which need some sound isolation too. I was thinking of building some wooden box with a maze of insulation and wood. Are there any existing designs that work really well? Are there any commercial solutions available? The holes are approximately 10cm/4" by 20cm/8".

As for acoustics I will build some basstraps and some insulation panels, but more importantly I am planning to soffit mount my monitor set. Does any of you have experience with this set (K+H O810 & O300) soffit mounted and are there any reliable resources on soffit mounting a subwoofer?

Here some pics of the current situation and the design in sketchup so far (including the sketchup file). I will post some pictures of my current studio later.

Hey, good intro.

"...there any reliable resources on soffit mounting a subwoofer?"

well, come on, really?

The benefit of flush mounting monitors is to give an even and controlled response...now apply that to a low frequency device like a sub woofer...what needs to be made even? It's all LF

_________________
Brien Holcombe
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Sound: You can't stop it, you can only try to contain it.

I did find some designs on soffit mounting normal monitors, but I wasn't sure if I could copy that to match a subwoofer.
Since the subwoofer would probably be near the floor so air circulation might be harder (for the amplifier on the back).

Is placement the same as placement in a non-soffit situation?
Are the same materials applicable or is concrete maybe better for that?

Hi Jean. Welcome!

Just a couple of comments:

Well, the beams are low but your diagram shows that you actually have 2.4m of ceiling height, so it should be possible to end up with a ceiling height of around 2.2 m. All you have to do is to work around the beams as well as possible, by carefully placing your rooms. And maybe also moving some of those pipes.

Well, not really! In reality, you need to worry about all 5 of the existing "walls" (four walls plus ceiling). Isolating a room is "all or nothing": you have to get all sides of the room isolated to the same level. So the "weak" walls need to be improved to the same level as the "good" walls, before you can even think about building your actual studio, which will consist of a second set of 5 walls, also all designed to the same level.

I'm not sure that I understand that. What is a "concrete/sand" wall? Concrete already has a LOT of sand in it: is that what you are talking about?

That will certainly get you good isolation! But the question is, how much isolation do you need? (in terms of decibels). You didn't mention that, but that's the key point to being able to design your room: You must start out by defining how much isolation you need.

What do you mean by "ratio" here? The ratio of sand / cement / aggregate / water to make the concrete? Or the room ratio (length / width / height)? Or something else?

It would REALLY help if you were to explain how you are planning to use the sand! Adding too much sand to your concrete mix does not improve the acoustic properties of the concrete very much: It just makes the concrete weak and crumbly, and in fact makes it worse as an acoustic isolator, since concrete with too much sand would be very porous.

They will transfer sound, yes, and especially impact noise. But since they will be outside of your studio (they are part of the outer leaf, not the inner leaf) that won't be a problem. Assuming that you also isolate your floor if you are going to have instruments or equipment in there that could couple to the floor, such as acoustic drums, bass amps. etc.

That won't work, if I understand what you have in mind. A single wall built across the existing room will not work. You mention MAM construction (also called "MSM", more correctly), but you don't seem to understand the basic principle: You MUST build an entirely separate room INSIDE the existing room, with air around it on all sides, and where the new structure does not touch the exiting room anywhere, not even one point. It is a totally separate construction, with air around it. The new walls sit on the existing floor and do not touch the existing walls or the existing ceiling. And the new ceiling sits on top of the new walls, and also does not not touch the existing walls or the existing ceiling. That is MAM construction!

You don't need ONE sliding glass door:you need TWO sliding glass doors! One goes in each leaf, with a large air gap between them. I've never heard of anyone home building sliding glass doors. You could do it, for sure, if you are good at carpentry, but it might just be easier (and quicker) to buy them ready-made.



Here are some threads about that:
viewtopic.php?f=2&t=1929&hilit=silencer&start=74
viewtopic.php?t=8425&start=2
viewtopic.php?f=1&t=11542&start=5
viewtopic.php?f=2&t=9761&start=0
viewtopic.php?f=2&t=11485&p=89855&hilit=silencer#p89855
viewtopic.php?f=2&t=11508&p=96578&hilit=silencer#p96578
viewtopic.php?f=2&t=13821&p=97928&hilit=+silencer+ducts+might+look+#p97928
viewtopic.php?f=1&t=15378&p=110641&hilit=+duct+silencer+#p110641

There are many others: Use the "search" feature on the forum to find them.

You'll need to do a lot more than that to make a concrete room sound good! The final acoustic treatment should be considered as part of the initial design, not something that is added on afterwards... If you make the wrong decision in the initial room design (such as creating a cubed room), then no amount of treatment can fix that: it would be a lousy room, no matter what you do to it afterwards. So even though isolation and treatment are two entirely different things, you still need to think about both at once in the design.

I'm not familiar with them, but from the rather limited information I found on-line, it looks like tt should not be too hard to mount those correctly: They seem to have the necessary bass roll-off control, according to some specs I found.

Like Brien said: Why would you want to soffit-mount a sub? I mean, you can if you want, but what's the purpose in that? A sub is basically a point source, and radiates pretty much equally in all directions, so soffit-mounting would only really manage to cut the total power radiated into the room, in half! If you succeeded in mounting it absolutely correctly (concrete baffle, perfect seal), you'd succeed in REDUCING the power output by 6 dB. It would be easier (and cheaper) to just turn down the volume 6 dB...

I don't see your isolation design in there at all! The control room is fully coupled to the existing walls, there is no ceiling in the control room, and the beam across the front of the room goes all the way through!

I'd suggest that your very first priority should be to figure out how much isolation you need, then look at the documentation to find construction methods that will give you that amount of isolation. Then, based on that, you can design your MSM structure for your control room, and another MSM structure for your live room.

- Stuart -

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I want this studio to amaze people. "That'll do" doesn't amaze people.

Not really, no. What acoustic benefit are you hoping to get from soffit mounting your sub? Why do you think you need to do that? Is it just for aesthetic purposes? If so, then build a simple wood frame, stretch cloth over it, and but the sub behind that.

Air circulation isn't the problem: acoustic benefit is the problem. if you really did soffit-mount the sub, you would do the ventilation shaft the same as for any other soffit-mounted speaker. But the question is why you would want to soffit mount in the first place? There are great benefits for soffit-mounting mains, but I don't understand what you think the benefits would be from soffit-mounting a sub-woofer.


- Stuart -

_________________
I want this studio to amaze people. "That'll do" doesn't amaze people.

Thanks for the reply.
because of this post:
http://www.johnlsayers.com/phpBB2/viewtopic.php?t=8173
I thought it wouldn't be necessary to isolate the ground floor and Wall C, because there is solid earth holding it back.
But I am convinced now that if I do i should do it as good as possible
So I will build 2 boxes in a box, I can probably get a lot of drywall for free so I will make large order of green glue soon.
I also skipped the sliding glass doors (much cheaper, easier to build and more effective)
I will probably end up with two or tree long vertical windows
Tomorrow I hope to have time to redesign the construction in sketchup
I'll post it as soon as I'm finished

With concrete/sand walls I meant hollow concrete blocks filled with sand

In your first post I counted almost 20 times where you typed "I" in respect to what you were going to do.

Not one time did it read "I have a lot to learn and really do not know much about this and wish you guys could help me to see that I do not know anything."

This is not a game and just because you say you will do something, I am more than confident that we will shoot 20 holes in it with accurate information...

You require time to read and time to establish a plan...outside of that, if you cannot or will not do that, you can expect help from this site to be minimum.

_________________
Brien Holcombe
_____________________________________________
Sound: You can't stop it, you can only try to contain it.