Building Home Studio - concept plan reveiled - feedback?

We did a few measurements yesterday. We maxed out around 115 dB. But there are a few things unclear to me... I guess the use of the SPL meter is only useful, when you use it together with a frequency meter? If you wan't a meaningful outcome, you need to know how much dB is produced at which frequencies, right? If you know this, then you can use the MSM Calculator to find out how much noise/sound is left. Another uncertainty: you can't just subtract the STC (from the calculator/the amount of dB your isolation creates) from the sound you produces, right? For example: if you produce 100 dB at 80 Hz and your walls etc. have a STC from 60 dB at Hz, there is 40 dB left? Seems illogical to me, because with every 10 dB, the noise doubles (to our human ears)... Last thing: the inverse square law. The first point where people can here me, is 5 meter away. So I wan't to calculate the loss of sound. I tried this a few times, but here is the thing: I can't figure out a way to really calculate from the source. This formula assumes that you're already at a certain distance from the source. And I imagine that in the first mm's you loose quite a lot, this is also what the formula indicates. How do I calculate this? What the loss of sound will be from the source?

We did a few measurements yesterday. We maxed out around 115 dB.

That's not unusual. Very typical, in fact.

I guess the use of the SPL meter is only useful, when you use it together with a frequency meter? If you wan't a meaningful outcome, you need to know how much dB is produced at which frequencies, right?

Sort of but not really... You measured using the "C" weighting curve, which already takes into account the way human ears work in relation to sensitivity of loud sounds. ("A" weighting is for quiet sounds). So that single number of 115 dBC already represents the sum total of all frequencies, where each one is weighted according to the way your ear perceives it. As you can see from the graph above, the weighting takes into account those frequencies. So if the levels around 300 Hz were very loud, that would cause the meter to read higher than if the levels around 30 Hz were very high, because your ear is a little less sensitive to 30 Hz than it is to 300 Hz. So from that point of view, the single number you measured is already indicative, to a certain extent, of the frequency content. If you measure the SAME sound on both A and C, then the difference between those two readings will tell you a lot about the spectral content: If the numbers are about the same, then most of the energy is in the mids and highs, but if there's a really large difference, then most of the energy is in the lows. For example, if you switch from C to A and the level drops 30 dB, then likely most of the energy is around the 50 Hz to 100 Hz bands, so it is very much "bass heavy". Yes it would be better to use a meter such as the Phonic PAA 3 which also displays the level of each individual 1/3 octave band in addition to the overall level, but when you do that you'll see that there really isn't much addition to learn that you didn't already know from just looking at the meter and listening with your ears: Whichever sound you are hearing loudest, is probably responsible for most of the number you are seeing. If the snare sounds really loud compared to the rest of the band, then you know that most of the energy is in the low mids. If the bass sounds really loud, then most of the energy is in the lows.

If you know this, then you can use the MSM Calculator to find out how much noise/sound is left.

Isolation calculators that give you a single number for estimated isolation are also weighted to show the total isolation, not the isolation at any give frequency. If the calculatos also gives you a detail graph, showing the estimated isolation in each 1/3 octave band, then that's more usueful, since you can compare it to the spectrum of the typical music you play, and to the Fletcher-Munosn (or other) equal loudness curves, to get an idea of how that sound will be perceived on the other side of the barrier. It's important to understand that the way humans perceive sound is not the same as the way a mic picks up sound.

Another uncertainty: you can't just subtract the STC (from the calculator/the amount of dB your isolation creates) from the sound you produces, right?

Actually, you can! That's what the entire exercise is about. You can simply subtract numbers, as long as you are crtain that you are using the SAME scale for the numbers, and you understand what you are doing. If you are producing 115 dBC inside, and your wall isolates 55 dB, then you will get roughly 60 dBC outside. Note that the measured levels must be the same weighting, but that the isolation does not mention weighting at all... because isolation is not a measure of sound levels! It's a measure of the mathematical difference between two OTHER numbers that are some type of weighting scale. It might seem like a subtle difference, but it is extremely important to get this. There is no such things as "50 dBC isolation", because isolation is not a measure of Sound Pressure Level! dBA, dBC, dBX and all the other weighting scales. Isolation is just the mathematical difference between two numbers: by itself, it does not measure any physical property of sound. It just compares two numbers, and those two numbers MUST be on the same scale. So you can't say that if you measured 100 dBC inside and 60 dBA outside that means you have 40 dB of isolation. Not true, because you cannot compare dBC with dBA. They are on two different scales. That would be the same as saying that if you have ten kilograms of apples and take away 3 pound of apples, that you now have 7 kg left: not valid, because pounds and kilograms are two different weight scales. This is very important to understand. You can only compare numbers that are on the same scale, and the DIFFERENCE between those numbers does not have any "scale" associated with it. It's just a difference. So it is perfectly valid to say that if you have 90 dBC inside and 50 dBC outside, then the wall is providing 40 dB of isolation. But NOT that it is providing 40 dBC of isolation...

For example: if you produce 100 dB at 80 Hz and your walls etc. have a STC from 60 dB at Hz, there is 40 dB left?

No. Because you are trying to compare kilograms of apples to bicycle wheels! :) STC is not a measure of anything at all: it's just an index number in a rating system, and is pretty much meaningless for talking about isolation in studios. STC is a single-number rating system that was devised several decades ago to give you an idea about how well an indoor wall, or door might isolate typical speech, or typical sounds in homes or offices. It does not consider full range music, and was never meant for that, so you cannot validly use it to say anything at all about isolation in studios, nor even isolation between outdoor sounds in cities, and indoors. It's fine if you want to know how well your bedroom wall isolates you from your kids screaming at each other in the room next door, but tells you nothing useful about how well your bedroom window isolates the sound of traffic on the freeway outside your window, or the sound of aircraft flying overhead, or the sound of the railway line a block away. Forget STC. What we are interested in for studio design, is "decibels Transmission Loss", often just abbreviated "TL". That's what we are talking about when we say a certain wall provides 45 dB of isolation. We really mean 45 dB of transmission loss. Which implies that a 100 dBC sound in one side will end up as 55 dBC on the other side, or also that a 100 dBA sound on one side will end up as 55 dBA on the other side. "TL" just tells you how much the numbers went down. And of course, the best idea is to look at the actual TL curve, because it is never a flat line: you always get more reduction in the highs than the lows, and there are usually some fairly serious dips and peaks that you might need to take into account. That sort of gets back to the point you were trying to make, but not really... :) (Sorry to be so cryptic, but this is a more complex question than it seems at face value!) So, if you really want to take things to extremes, you could indeed measure the SPL for each frequency band for every instrument that you plan to record, then look at the TL curve for the type of wall you plan to build, subtract the numbers for each individual frequency band, and that would show you what the sound levels for each frequency would look like on the other side of your wall. You could then compare that to the Fletcher-Muson curves, choose an arbitrary phon level that you like, and see if your calculated levels happen exceed that phon curve at any given point. That would be the real indication of how loud you would HEAR that sound on the other side of the wall. However, you would have to do that without using any weighting curves on your meter, because the weighing curves are actually derived from the equal loudness curves, so you'd be taking them into account twice if you used "A" or "C" weighting on your meter. You'd need a meter that can do "flat" or "unweighted" readings... Or you could just measure using "C", subtract the isolation number, and be done with it! :)

Seems illogical to me, because with every 10 dB, the noise doubles (to our human ears)...

When comparing levels on the same scale, and across the entire spectrum, yes. But not for individual tones. You can say that you listened to the song inside, then outside, and thought it was half as loud, so the isolation must be about 10 dB. True. But you can't do that for individual tones, such as listening to the bass play a low E inside, go outside estimate half as loud, and say that means the wall isolates 10 dB at 41.2 Hz. Not true, because your hearing isn't linear. Take a look at the equal loudness curves, and you will see that they are very close together at 40 Hz, but much further apart at 4 kHz, so an estimate of "half as loud" would be very different in actual dB levels for those two tones. As with most rules of thumb, they work when you use them in the right way, but they don't hold true for all situations. The "10 dB is twice / half as loud" is only true for typical broad-spectrum sounds, not individual notes or narrow frequency bands.

Last thing: the inverse square law. The first point where people can here me, is 5 meter away. So I wan't to calculate the loss of sound. I tried this a few times, but here is the thing: I can't figure out a way to really calculate from the source. This formula assumes that you're already at a certain distance from the source. And I imagine that in the first mm's you loose quite a lot, this is also what the formula indicates. How do I calculate this? What the loss of sound will be from the source?

The "standard" measuring distance for sound levels is 1 meter, or three feet (roughly). But that refers to sound sources that are small with respect to that distance, or similar in size. So you can measure a guitar, speaker, or vocals at 3 feet, but you would not want to measure a a concert grand piano at 3 feet, nor a cruise ship's diesel engine at 3 feet, because the piano is large in relation to 3 feet, and the ship's engine is huge in relation to that 3 feet. You would be measuring only a small part of the total sound put out by that engine: perhaps just the sound of one valve, not the entire engine. There are methods for figuring that out with respect to very large sound sources, but for the outside wall of single story house, it would be reasonable to measure at a distance of maybe 6 to 9 feet or so. Even at 3 feet, you won't be too far wrong. I hope I haven't confused you too much! decibels and sound levels are a complicated thing... and that's without even going into the technicalities of sound power vs. sound pressure vs. sound intensity.... nor going into why it is fine to just SUBTRACT the numbers even though dB is a logarithmic scale, and subtracting logs is the same as dividing the base numbers, so how can it be valid to divide the numbers when you just want to know how much the subjective level went down... :) (it is valid: don't worry about it) That would just complicate things too much. And you thought you were asking a simple question! :) Simple answer? "It's complicated".... - Stuart -

If you measure the SAME sound on both A and C, then the difference between those two readings will tell you a lot about the spectral content: If the numbers are about the same, then most of the energy is in the mids and highs, but if there's a really large difference, then most of the energy is in the lows. For example, if you switch from C to A and the level drops 30 dB, then likely most of the energy is around the 50 Hz to 100 Hz bands, so it is very much "bass heavy".

Interesting! We will try this the next time.

If the calculatos also gives you a detail graph...

It does! I use the one posted on this forum: https://docs.google.com/spreadsheets/d/ ... 1543869474

What we are interested in for studio design, is "decibels Transmission Loss", often just abbreviated "TL"... ...Or you could just measure using "C", subtract the isolation number, and be done with it! :)

All right, so no frequency meters etc., just C weighting and also a A weighting to see if the frequency range is bass heavy or not. I think it is, with drums and bass. And STC --> I will forget this. TL it is. You're talking about 'the isolation number' and '45 dB Transmission Loss' --> you mean the loss at a certain frequency? Or in general? And if the latter is the case, how do I know what this number is? When I use a calculator like the one above

You can say that you listened to the song inside, then outside, and thought it was half as loud, so the isolation must be about 10 dB. True. But you can't do that for individual tones, such as listening to the bass play a low E inside, go outside estimate half as loud, and say that means the wall isolates 10 dB at 41.2 Hz. Not true, because your hearing isn't linear.

Didn't know that!!

The "standard" measuring distance for sound levels is 1 meter, or three feet (roughly)... ...but for the outside wall of single story house, it would be reasonable to measure at a distance of maybe 6 to 9 feet or so. Even at 3 feet, you won't be too far wrong.

I guess I understand what you mean, but I'm not completely sure. So let's say the source (a band jamming) is producing 115 dBC. The isolation of the structure has a Transmission Loss of 50 dB. There is 65 dBC left. Then I use the inverse square law (http://hyperphysics.phy-astr.gsu.edu/hb ... prob2.html) --> fill in 3 feet at 'd1', fill in 5m at 'd2' and 65 in I2 --> outcome is 50 dB --> so when you're 5m away, you hear 50 dBC? Or am I completely wrong now and am I confusing dB with dBC and dBA?

And you thought you were asking a simple question! :) Simple answer? "It's complicated"....

Complicated it is... man!!! But you guys are amazing. The time and effort you take to help rookies like me...There is hope in this world! It will take some time to completely get a grasp of everything, but with baby steps I'm getting closer! I'm not in a hurry and I want to know what I'm doing

I guess I understand what you mean, but I'm not completely sure. So let's say the source (a band jamming) is producing 115 dBC. The isolation of the structure has a Transmission Loss of 50 dB. There is 65 dBC left. Then I use the inverse square law (http://hyperphysics.phy-astr.gsu.edu/hb ... prob2.html) --> fill in 3 feet at 'd1', fill in 5m at 'd2' and 65 in I2 --> outcome is 50 dB --> so when you're 5m away, you hear 50 dBC? Or am I completely wrong now and am I confusing dB with dBC and dBA?

Yes, I think this is right. Because everything a human ear perceives is noted in dBC.

You're talking about 'the isolation number' and '45 dB Transmission Loss' --> you mean the loss at a certain frequency? Or in general? And if the latter is the case, how do I know what this number is? When I use a calculator like the one above

This is the peak of the graph in a C weighting graph, I guess, but I'm not 100% sure...

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Thanks for all the help till this point. Measuring etc. is a lot more clear now. It's time to start doing a few things. 1. Remove some tiles and dig --> to see at what point we will encounter ground water. Ideally we want to go 30 cm down, so our final room will be around 2.3m high; 2. Remove the windows and sliding door and replace this with brickwork (mason) --> so the outer walls are airtight and all stone/cement I'll keep you posted and I'm sure I will be back with more updates en questions...

Sounds like a good plan to get started! But do make sure you have your entire design complete BEFORE you start any actual building... :) - Stuart -

I have removed quit a lot of stones and began digging. At a few points it's around 35 cm deep. The sand is black en a little damp, but not real wet. I will wait a few days to see if there will appear ground water... Another questions: We're going to dig 30/40 cm everywhere --> and then pour concrete for the floor (we will do this when the plan is 100% worked out). On the complete outside of the concrete flour, there will come the inside walls. What to do with the small space between de concrete and the outside walls? if we also pour concrete there, there is no floating floor... But if we do nothing, it will be very moisty --> what to do? Waterproof canvas or something?

kingrat wrote:

I have removed quit a lot of stones and began digging. At a few points it's around 35 cm deep. The sand is black en a little damp, but not real wet. I will wait a few days to see if there will appear ground water... Another questions: We're going to dig 30/40 cm everywhere --> and then pour concrete for the floor (we will do this when the plan is 100% worked out). On the complete outside of the concrete flour, there will come the inside walls. What to do with the small space between de concrete and the outside walls? if we also pour concrete there, there is no floating floor... But if we do nothing, it will be very moisty --> what to do? Waterproof canvas or something?

Hi kingrat, Is unlikely you will need to have a floating floor. Floating floors cost thousands to do right (thick reinforced concrete pad with resilient springs etc.). A concrete slab damped by the earth will isolate 70dB before flanking becomes a problem. If you're not building 65 to 70dB of isolation in your walls, ceiling, HVAC, windows and doors, don't float your floor :D. Follow your local building regulations on how to build a solid concrete floor. Eg. Do you require a damp proof membrane, do you need to add thermal insulation, do you need expansion joints, do you need to "tie" it to the original foundation by drilling and installing re-bar. The building regs should tell you about controlling moisture in buildings in your climate. Once you know the regulations, then build that and you're golden :D Dan

Thanks for your answer Dan!

Follow your local building regulations on how to build a solid concrete floor. Eg. Do you require a damp proof membrane, do you need to add thermal insulation, do you need expansion joints, do you need to "tie" it to the original foundation by drilling and installing re-bar. The building regs should tell you about controlling moisture in buildings in your climate.

I will try this!

Is unlikely you will need to have a floating floor...

But if the inner and outer walls touch the same floor you get contact sound, right? Doesn't that reduce the effect of the room-within-a-room? If you lay a moisture resistant canvas, or something like that, on the sand (attach to outer wall) -> poor concrete, but leave a gap on each side --> you shouldn't have too much trouble with moisture and you do have a floating wall. Or do I completely overlook something?

But if the inner and outer walls touch the same floor you get contact sound, right? Doesn't that reduce the effect of the room-within-a-room?

If they are both on an un-damped resilient floor, flexible floor, then yes. But if they are both on a very well damped, massive, rigid floor, then no. A properly-built slab-on-grade foundation rests on good old mother earth. The entire planet is your damping system. It's hard to beat that! 6" of solid reinforced concrete on a good gravel/sand base is a huge chunk of very solid, rigid, massive floor. Yes, you will need a waterproof barrier under the slab, yes you might also need foundation insulation, depending on local conditions, but even with all that, it's still a hell of a foundation. The basic question here is: how much isolation do you need? With a good slab-on-grade in an independent building that doesn't touch any other building, you can get upwards of 70 dB of isolation, if you build everything else properly. That's very, very good. That's about ten thousand times better than a typical house wall, in the sense that it blocks about ten thousand times as much sound as a normal stud wall with drywall on both sides. Do you need MORE than that? If so, then you are going to need to do some major design here, and it's going to get very, very expensive. If that is, indeed, the situation, and you do need more than 70 dB of isolation (highly unlikely, but just assuming....), it would still be better to do a slab-on-grade foundation and simply float the entire studio on top of that, on another slab.... properly decoupled with suitable isolation springs, carefully calculated. But to get to that level, we are basically talking about one concrete bunker floated inside another concrete bunker, and a budget with lots of zeroes on the end. What you are proposing is a to have one set of foundations for the outer-leaf walls and ceiling, then a separate, isolate slab for the inner leaf walls and ceiling. That can work too, but it's not going to be as good as a fully floated room tuned with a very low MSM frequency, and it does have the drawback you already noticed: How to keep the two foundations decoupled, but still water-tight and air-tight? It is possible, but whatever method you use for that is not going to be perfect, and will flank a small amount of vibration between the two, no matter what you do. It's also rather expensive to do that: Isolated slab can work, but is seldom needed, unless you have very high isolation needs. So this all boils down the basic question: How much isolation do you need? What is your goal, in decibels? Once you have that figure defined, THEN you can look at construction methods and materials that will get you there. - Stuart -

Thanks Stuart! If we achieve 70 dB isolation, I would be euphoric!! So: that's enough for sure. But I don't think we'll get there, because the air gap and walls can't take too much space --> then the studio will be to small. But we can get close. If we replace the wood and windows with brickwork. Unfortunately I can't find a calculator or something else to measure the isolation of a stone wall (and of course the roof isn't from stone). So, if you say, the semi-decoupled floor (as a proposed) won't do too much, I guess we need to make a concrete slab, build the stone walls and then measure what the isolation of these structure is. Then we can decide how much isolation we need from the inner structure. Is this the right way to do it, you think?

You can calculate the isolation you can expect from your walls/roof with this calculator: viewtopic.php?f=1&t=21770. If the material you want to use is not listed then just add a custom kg/m2 for your material. You need to design the wall as a system. Don't build one leaf then decide on the inner leaf afterwards, as you may have to have different cavity wall ventilation requirements based on material used. Just use the calculator to get an idea of what you can expect (in theory) and lower the value a bit for the real world throwing a spanner in the works. You could get 70dB from your walls yes, but I can almost guarantee you won't get that unless you have a huuuge budget for doors and HVAC. The walls are almost never the problem when building for isolation; it's all the bits you have to cut into them! You would need large air cavities between your doors (think of an entrance way) with triple (or more) magnetic and drop seals on steel/lead lined doors. Windows with two panes of 1" glass and a 2' cavity. You would need massive silencer boxes, with 5 or 6 baffles in each, all made of multiple layer thick mdf/steel. You would need to have your electrical entry point in conduit within the concrete slab and then sealed (possibly needing silencer boxes on each end). Walls are the easy part! :lol: In the end though, it's unlikely you need 70dB of isolation at low frequencies anyway. :)

You can calculate the isolation you can expect from your walls/roof with this calculator: viewtopic.php?f=1&t=21770. If the material you want to use is not listed then just add a custom kg/m2 for your material.

Ah, all right. That's the way to calculate materials that are not listed. Let's see if I can find out how to fill this in exactly. I am familiar with this calculator, via here I did all the calculations, but not with the custom kg/m2

You need to design the wall as a system. Don't build one leaf then decide on the inner leaf afterwards, as you may have to have different cavity wall ventilation requirements based on material used.

Yes, you're absolutely right. I will start to build the outer walls when I know where ventilation comes in/out and where power comes in.

In the end though, it's unlikely you need 70dB of isolation at low frequencies anyway. :)

True, I don't need 70 dB isolation. And there is not an exact number I'm trying to achieve. I have a small space + not too much money (around 6000) --> so I will try to get the best out of this. And I also see this as an experiment. In the future I would like to build a bigger studio. Even if I could just play/record electric guitar and sometimes drums and bass (when it's not busy here, and that's very often the case), I would be happy. But of course, it would be very nice, if we can reach a comfortable isolation level. I'm still waiting for the rain, so I can see if there comes water in the holes I dug. Then the next steps will be: - Drawing a concrete plan, for inner walls + ventilation + doors + power etc. - Remove the whole current floor and dig, step for step

kingrat wrote:

I have a small space + not too much money (around 6000)

I think you will need a bigger budget I'm afraid. Some things take huge chunks, for example: the best AC installation quote I could get was £1400. You also need to factor in little things that add up, like caulk, I've spent over £200 on caulk alone. I've had 5 boxes of the stuff. My budget had been £12000 and it's getting tight toward the end. Dan

My studio will be far from professional, so I think I will economize on the HVAC-part... Of course I want fresh air, but I'm not 100% sure I will be implementing a heating and airco system. I live in the Netherlands, where the winters are quite soft and the summers not too hot;) I realize a HVAC is important, but my budget is tight and I won't be sitting there whole day. Just playing, recording & jamming a few hours per week and a bit longer in the weekends. About calculating materials that aren't listed in de MSM calculator. Can someone explain me how I do this? I can't really figure it out...

kingrat wrote:

I'm not 100% sure I will be implementing a heating and airco system

I was thinking the same as you at first. In the UK the weather has no real extremes. Outdoor temperatures are cooler than indoors 11 months of the years on average. Think of it like this though. Have you ever been in an air tight room? You will probably answer no unless it's a recording studio. Have you ever been in a "stuffy" room? The problem is not about cooling the room because of outdoor temperatures, it's about getting rid of the heat and humidity you and your equipment produce. In a house you have passive ventilation and hard reflective walls, you might open a window, or a door to another room. In your studio you have none of those. You are surrounded in cubic metres of thick fibreglass/mineral wool (an excellent thermal insulator). The ventilation for oxygen is not going to remove this heat and vapour sufficiently, on hot humid days especially it'll feel like a steamy bathroom. Also AC provides heat too. What are your plans for the winter? If you try it out without designing for aircon and then find you need it, you'll have to break into your nice finished walls to install AC pipework bending inside the cavity, they can't just go straight through one side to the other. Of all the things to save money on, I wouldn't save it by not fitting AC. Maybe go with cheap laminate flooring and lighting, not fitting a window (this would save hundreds possibly), learning how to fit the wiring yourself, so you don't need to pay an electrician as much. You live in a country that doesn't regularly fit AC to residential buildings, its the same here, I know literally one person who has aircon in their house. I'm still fitting AC to my studio. I recommend you do everything you can to do the same, it will be worth it. Dan

Thanks for your advise Dan. I will look into the possibilities of a budget HVAC system. And I have indeed, I think, not been in an airtight room before... I know this sounds bush-league, but I'm a pragmatist: what if I would open the doors for a few minutes every hour (when I'm busy)? And put a small electric heater in there, for cold times. And of course I am planning to have fresh air coming in and out and maybe I can install a blower/pump, so the air circulates and the studio get's vented --> if you do all this, would that be all right?

kingrat wrote:

Thanks for your advise Dan. I will look into the possibilities of a budget HVAC system. And I have indeed, I think, not been in an airtight room before... I know this sounds bush-league, but I'm a pragmatist: what if I would open the doors for a few minutes every hour (when I'm busy)? And put a small electric heater in there, for cold times. And of course I am planning to have fresh air coming in and out and maybe I can install a blower/pump, so the air circulates and the studio get's vented --> if you do all this, would that be all right?

If you're installing ventilation for oxygen (which you definitely need) then opening a door won't provide additional benefits on top of that. The ventilation needs to be active (with a high volume fan), at least 6 compete air changes per hour and this will provide slight dehumidification, but only if outdoors is less humid than indoors. In wet summers there won't be anywhere to dump the vapour in the air, and it might even bring additional moisture into the room. In the end there isn't really an alternative to Air conditioning, in the same way there isn't really an alternative to a fridge. A cooler box will keep the food OK for a while, but it'll be soggy and luke warm after a little while. You might be OK without AC for a while relying on ventilation, but it could get humid and horrible in the room and you regret it. :? I went for the cheapest setup for HVAC that preserved my sound isolation. I have an extractor fan for ventilation, providing over 6 air changes per hour, and a mini-split AC to control humidity and temperature. The AC has a heat pump to warm in the depths of winter too. The bare bones cheapest option for AC, requires an adjacent small cupboard room to the studio, used as a mechanical room. In this little room you fit a standard "window" AC unit through a hole in the wall, then you have a fan and ducting passing the treated air through the isolated wall into the studio. These ducts still require the usual silencer boxes. Dan

In the end there isn't really an alternative to Air conditioning,...

+1 What he said! :) - Stuart -

Thanks guys. I'm convinced now I need an HVAC system. I just have to find relative cheap way to do this. In the next few weeks I will make a financial oversight. We'll know what to do: - Digging, pour concrete - Bricklaying & making roof airtight - Build room-within-a-room: wooden studs with rockwool attached to outer wall. Air in between. wooden studs with rockwool - gypsum + green glue + gypsum - 2 doors: plain doors, mass added & rubber strips. - HVAC system placed above the inner room. Pointed roof, so enough space. In/out in inner + outer wall. On outside of outer wall silencer boxes - Fixing power: if there's not enough watts, fix it. If there's interference, fix it. That's about it, roughly... Sound easy, but I know better...

kingrat wrote:

Thanks guys. I'm convinced now I need an HVAC system. I just have to find relative cheap way to do this. In the next few weeks I will make a financial oversight. We'll know what to do: - Digging, pour concrete - Bricklaying & making roof airtight - Build room-within-a-room: wooden studs with rockwool attached to outer wall. Air in between. wooden studs with rockwool - gypsum + green glue + gypsum - 2 doors: plain doors, mass added & rubber strips. - HVAC system placed above the inner room. Pointed roof, so enough space. In/out in inner + outer wall. On outside of outer wall silencer boxes - Fixing power: if there's not enough watts, fix it. If there's interference, fix it. That's about it, roughly... Sound easy, but I know better...

Hi kingrat, You don't need studs attached to your outer brick wall usually. It's there a reason you have those listed? You can get rockwool that is self supporting and doesn't need a frame to hold it, just stack it up, then build your other frame in front of it. Also as long as your rockwool isn't too dense you don't want an air gap at all. Research had found that fully filling is best, even fluffy loft insulation works fine inside an MSM wall and doesn't reduce performance. Dan

Hi Dan, I've listed those bricks here because I thought this was needed to keep the rockwool in place. So you would say: just fully fill the space between the inner and outer walls? With not too dense rockwool. Another question: you need airco/heating/de-moisturize etc. in the studio --> but doesn't the space in between the walls doesn't get moist? And if so, how can you prevent this?

kingrat wrote:

Hi Dan, I've listed those bricks here because I thought this was needed to keep the rockwool in place. So you would say: just fully fill the space between the inner and outer walls? With not too dense rockwool. Another question: you need airco/heating/de-moisturize etc. in the studio --> but doesn't the space in between the walls doesn't get moist? And if so, how can you prevent this?

Not sure I follow your point about the bricks, but yes just fully fill any cavity in your wall with light insulation. You definitely need to find out how cavity wall moisture is controlled in your area. If the only options acceptable to building regulations in your part of the world are to ventilate your cavity then you will need to build 3 leaf walls. But there are some alternatives. You can look here for ideas: https://www.buildingscience.com/documents/digests/bsd-106-understanding-vapor-barriers Figure 4 looks like it could be used for studio design in any part of the world, without issue, we just would make our internal framed wall decoupled from the concrete blocks. Dan

Not sure I follow your point about the bricks...

Woepsiee, I meant studs...

Figure 4 looks like it could be used for studio design in any part of the world, without issue, we just would make our internal framed wall decoupled from the concrete blocks.

So if I understand this correctly: I have to stucco the outside of my outer wall and paint this with latex paint. And on the inside of the outer wall I need to put rigid insulation. Then a small airgap --> then the rockwool (not too dense) + gypsum (+ green glue gypsum) --> is this correct?