Hatchannels and drop ceiling systems, in combination?

Hi! I'm looking at how to design my ceiling. For sound-isolation I believe a ceiling hatchannel or similar would be good. Something like this:

But for ceiling-acoustic I think a broad-band absorber like a drop-ceiling would be best, 50-100mm insulation on T-brackets. Something like this:

My question is: Has anybody used these system in combination? -The suspended false ceiling 100-400mm under the decoupled gypsum?

For sound-isolation I believe a ceiling hatchannel or similar would be good.

Hat channel does not isolate or decouple. To do that, you need "resilient channel" (RC) which looks similar but is actually very different. It is specifically designed to decouple the drywall form the joists. Another option is to use hat channel in conjunction with isolation clips, such as RSIC clips, which correctly decouple the hat channel from the joists. But hat channel by itself is no use.

But for ceiling-acoustic I think a broad-band absorber like a drop-ceiling would be best,

A drop ceiling is not going to do that much for you, and so-called "acoustic ceilings" are not really much good for acoustics in studios. They are designed to treat the typical low-level noise found in offices, shops, schools, etc. Mostly people talking, phones, office equipment, etc. They are pretty useless for loud, full-spectrum music. It would be much better to treat your ceiling in the traditional manner for studios, with a proper ceiling cloud and absorption where necessary. - Stuart -

Thanks!

Soundman2020 wrote:

For sound-isolation I believe a ceiling hatchannel or similar would be good.

Hat channel does not isolate or decouple. To do that, you need "resilient channel" (RC) which looks similar but is actually very different. It is specifically designed to decouple the drywall form the joists. Another option is to use hat channel in conjunction with isolation clips, such as RSIC clips, which correctly decouple the hat channel from the joists. But hat channel by itself is no use.

Yes, hat channel in conjunction with isolation clips was what I was thinking about.

But for ceiling-acoustic I think a broad-band absorber like a drop-ceiling would be best,

A drop ceiling is not going to do that much for you, and so-called "acoustic ceilings" are not really much good for acoustics in studios. They are designed to treat the typical low-level noise found in offices, shops, schools, etc. Mostly people talking, phones, office equipment, etc. They are pretty useless for loud, full-spectrum music. It would be much better to treat your ceiling in the traditional manner for studios, with a proper ceiling cloud and absorption where necessary. - Stuart -

Ok, seems like I don't understand what a proper ceiling-cloud and absorption is then. I thought 30-100mm/1-4" high density absorption, suspended 10-30cm/4-12" all over the ceiling would give good broadband absorption. Isn't this a good idea. But this is a false ceiling right? and can't be used as inner leaf for the ceiling? I have two concerns regarding my sound-proofing for my ceiling 1) A need to beef the current construction up to 40db (ground-floor to second-floor) 2) Deal with the roof-ventilation/soffit-vents that is on the sides, and maintain 60db to the outside Wall-design1 here: viewtopic.php?f=1&t=18030#p126164 So, is there a design that can deal with both the isolation and the absorption in one solution?

"So, is there a design that can deal with both the isolation and the absorption in one solution?" Fully decoupled environment, mass/air/mass does the isolation, interior treatments does the other.

xSpace wrote:

"So, is there a design that can deal with both the isolation and the absorption in one solution?" Fully decoupled environment, mass/air/mass does the isolation, interior treatments does the other.

Ok, thanks! Since I only need 40db for the ceiling to next floor, I was hoping I wouldn't have to build a full-structure inner ceiling. The challenge for me seems however that there are holes for the roof ventilation, like this: and this is the outer leaf of the mass-spring-mass on that point, that should hold 60db. The roof in itself will give some sound-proofing, and it will be both distance and many centimetres of insulation to the edge of my room. Blocking the soffit-vents, would undermine the original design.. hm..

Hi G-Sun, I'm a bit confused reading some of your target 'goals' of isolation. Often discussed here is the 'lowest common denomination' with regard to isolation. Basically, the 'weakest' link [or least isolation] overrides anything with more isolation. I may, very well, have misread ... but I still wanted to bring it to attention.

RJHollins wrote:

Hi G-Sun, I'm a bit confused reading some of your target 'goals' of isolation. Often discussed here is the 'lowest common denomination' with regard to isolation. Basically, the 'weakest' link [or least isolation] overrides anything with more isolation. I may, very well, have misread ... but I still wanted to bring it to attention.

Hi RJ :) Yes, I understand the confusion. I'll try to explain: My new studio will be on first floor. Sound-proofing for all walls, floor and ceiling is approx. 60db to the outside (some cost/work considerations should be taken into account , but at least 50db) However for ceiling and south-wall, the studio will have two existing walls/roof giving sound-proofing. I'll say my sound-isolation needs studio to hall/bathroom and first-floor is 40db. And generally the exicting second-wall structure will give me at least 20db, thus 60db is mainained for the whole build. Agree? The problematic part is, as I see it, the roof-corners of my studio to roof edge of the house with roof-ventilation. So, I need to come up with a solution for this. Broadband-ceiling absorbers for the studio-ceiling needs be thought through in this design as well. I'll make some 2D/3D drawings of the whole corner, but would like to get a better understanding of my needs and possible solutions first :)

Sound-proofing for all walls, floor and ceiling is approx. 60db to the outside ... I'll say my sound-isolation needs studio to hall/bathroom and first-floor is 40db. ... However for ceiling and south-wall, the studio will have two existing walls/roof giving sound-proofing. ... And generally the exicting second-wall structure will give me at least 20db, thus 60db is mainained for the whole build. Agree?

Not agree. First, getting 60 dB of transmission loss is a big deal. That is not easy to do, and there are not many methods / materials available to you that will achieve such a high level of isolation. We are not talking about STC here, since this is music, so 60 dB of isolation is not going to be easy. Second, you can't just add up transmission losses, since we are talking decibels here, which is a logarithmic scale. Third, your isolation system is a SYSTEM, not a set of components. It is a complete envelope that must have the same level of isolation in all directions, not one level in one direction and a different level in anther direction. It is only as good as the weakest link. So if you have 40 dB of isolation in one direction, and 60 dB in another direction, and 50 dB in yet another direction, well, your TOTAL isolation is 40 dB: the same as the lowest level.

Since I only need 40db for the ceiling to next floor,

No, you still need 60 dB, if that is your design goal. It is not possible to design a room that provides 60 dB of isolation through one wall and only 40 through another wall. What you would get is 40 dB.

Broadband-ceiling absorbers for the studio-ceiling needs be thought through in this design as well.

You are confusing isolation with treatment: Broadband ceiling absorbers are part of the treatment of the room, and will have no useful effect at all on the isolation. They are two totally different things.

The problematic part is, as I see it, the roof-corners of my studio to roof edge of the house with roof-ventilation.

In cases like that, where ventilation is required, the only real solution is to build a three-leaf system for the roof, where most to the mass is on the middle leaf, and the roof is the third (outer) leaf. Also, your floor plan does not show the correct layout and geometry for the speakers and listening position, and you have the door in the exact location that you will need for corner bass trapping. But the worst issue of all is that your room is perfectly square!!! :shock: You show that it is 5.94 m long by 5.92 m wide. Before doing anything else, I would change that. You need to move at least one of the walls to fix that, before you even consider how to isolate the room.

My new studio will be on first floor.

Just checking to make sure here, since some countries call things by different names. Do you mean that your studio will be on the ground floor, built on top of a concrete slab that rest on the ground? In some places, "first floor" means the next floor up, above the ground floor... - Stuart -

Soundman2020 wrote:

My new studio will be on first floor.

Just checking to make sure here, since some countries call things by different names. Do you mean that your studio will be on the ground floor, built on top of a concrete slab that rest on the ground? In some places, "first floor" means the next floor up, above the ground floor...

Sorry, quite observant. My studio will be on ground floor (and yes, we would call that first floor here)

Thanks a lot! Many of these discussions belong to my main thread, found here: viewtopic.php?f=1&t=18030

Soundman2020 wrote:

Sound-proofing for all walls, floor and ceiling is approx. 60db to the outside ... I'll say my sound-isolation needs studio to hall/bathroom and first-floor is 40db. ... However for ceiling and south-wall, the studio will have two existing walls/roof giving sound-proofing. ... And generally the exicting second-wall structure will give me at least 20db, thus 60db is mainained for the whole build. Agree?

Not agree. First, getting 60 dB of transmission loss is a big deal. That is not easy to do, and there are not many methods / materials available to you that will achieve such a high level of isolation. We are not talking about STC here, since this is music, so 60 dB of isolation is not going to be easy.

Ok. Yes, and maybe 60db is a little to much for me, cost, labor and design taken into account. I think 50db is to low - tried one place with 50db and it's not really good enough. So, maybe I should aim for something like 56-57db.. ? Anyway, yes you're right.

Second, you can't just add up transmission losses, since we are talking decibels here, which is a logarithmic scale. Third, your isolation system is a SYSTEM, not a set of components. It is a complete envelope that must have the same level of isolation in all directions, not one level in one direction and a different level in anther direction. It is only as good as the weakest link. So if you have 40 dB of isolation in one direction, and 60 dB in another direction, and 50 dB in yet another direction, well, your TOTAL isolation is 40 dB: the same as the lowest level.

Ok, I'm aware of your point of view (But thanks for stressing it) I'll reformulate my isolation thinking.

Since I only need 40db for the ceiling to next floor,

No, you still need 60 dB, if that is your design goal. It is not possible to design a room that provides 60 dB of isolation through one wall and only 40 through another wall. What you would get is 40 dB.

Broadband-ceiling absorbers for the studio-ceiling needs be thought through in this design as well.

You are confusing isolation with treatment: Broadband ceiling absorbers are part of the treatment of the room, and will have no useful effect at all on the isolation. They are two totally different things.

Ok, I thought maybe a false ceiling all over with 100mm/4" high density rockwool would add something to the isolation. Anyway, if I am to suspend a false ceiling from my current ceiling, and doing other things to my current ceiling, I would have to take it all into consideration regarding total-weight and what the structure could take, right?

The problematic part is, as I see it, the roof-corners of my studio to roof edge of the house with roof-ventilation.

In cases like that, where ventilation is required, the only real solution is to build a three-leaf system for the roof, where most to the mass is on the middle leaf, and the roof is the third (outer) leaf. Also, your floor plan does not show the correct layout and geometry for the speakers and listening position

Like 38%, you're thinking of? Well, recording-spot has priority over mixing-position for me, so it's a balance mainly concerning room-space. But, I'm very happy for input regarding this: viewtopic.php?f=1&t=18030#p126109

, and you have the door in the exact location that you will need for corner bass trapping.

Yes, how bad is that?

But the worst issue of all is that your room is perfectly square!!! :shock: You show that it is 5.94 m long by 5.92 m wide. Before doing anything else, I would change that. You need to move at least one of the walls to fix that, before you even consider how to isolate the room.

Thanks, my question is: How much is enough? -balancing space with acoustic. Thanks a lot!

G_sun - nothing beats decoupling completely. Forget RC hat etc. If you can build a new ceiling -totally detatched from your existing ceiling you will win out in the end.

John Sayers wrote:

G_sun - nothing beats decoupling completely. Forget RC hat etc. If you can build a new ceiling -totally detatched from your existing ceiling you will win out in the end.

Hi John! Yes, I sort of know. The reason why I'm thinking otherwise is: - I already have a 2-4leaf ceiling consisting of first floors floor and building roof. - Ceiling-hight - Easier construction, less cost, less work But if you all say it's not possible/worthwhile to achieve 56db this way, then, yes I have to design for a new inner-ceiling construction. That's really what this thread is about :) Edit: On the other hand, building an inner ceiling using e.g. I-beams could be an easier solution than tightening the second leaf of a three-leaf roof, for all I know. Cost, labour, difficulty ceiling-hight and isolation-values are the factors..

A note regarding this first sketch: This is just the current outer walls. So the placement of the inner walls will change the dimensions. My doughter wants me to put in a smiley: :yahoo: :)

So this room is only 6.5 feet tall? (2000 millimeters according to drawing)

I may be wrong but I think the 500mm below the studs on the drawing is block work.

Yes, 250cm roof hight. 50cm leca wall.

That was why I asked.

Just remember that ceiling cavities can not be filled with anything that will deter roof ventilation or under eave/soffit ventilation.

ets80 wrote:

Just remember that ceiling cavities can not be filled with anything that will deter roof ventilation or under eave/soffit ventilation.

Thanks! Yes, this is a question I've been wondering about. Seems like I need to get a better understanding of wall- and roof-ventilation regarding woodframe-studio-builds. Any links on this, or should I start a new thread? Remember climate: Warm inside, cold outside

...or should I start a new thread?

Try to keep ALL of your questions in one single thread, which should be your design thread (and when you are ready to actually start building, we'll move that the to the "construction" section of the forum for you). If you ask questions all over, you'll find it difficult to keep track of where you asked them all, and what responses you got! So it is better to keep everything in one place. - Stuart -

Soundman2020 wrote:

...or should I start a new thread?

Try to keep ALL of your questions in one single thread, which should be your design thread (and when you are ready to actually start building, we'll move that the to the "construction" section of the forum for you). If you ask questions all over, you'll find it difficult to keep track of where you asked them all, and what responses you got! So it is better to keep everything in one place. - Stuart -

Thanks Stuart, I did a fairly good start in my main-thread, but so far just RJ has entered that thread.. Besides I need to get a general understanding of the topic wall/roof-ventilation and practical solutions for studio-building.

ets80 wrote:

Just remember that ceiling cavities can not be filled with anything that will deter roof ventilation or under eave/soffit ventilation.

Idiot...

Put my questions about wall- and roof-ventilation here: viewtopic.php?f=1&t=18064#p126318