952 Studios Design Planning

#46

the live room will have different characteristics than the critical listening room... depending on the ceiling structure of the live room, you could leverage the ceiling-wall "corners" for a large soffit which provides routing for hvac, absorption, lighting etc. imho, the small "trap" you would have in the live room would be inconsequential compared to have that additional space in the control room.

#47

gullfo wrote:Source of the post the live room will have different characteristics than the critical listening room... depending on the ceiling structure of the live room, you could leverage the ceiling-wall "corners" for a large soffit which provides routing for hvac, absorption, lighting etc. imho, the small "trap" you would have in the live room would be inconsequential compared to have that additional space in the control room.

Thanks for the explanation Glenn. I will take your advice and update that design. Something this small wont need me to resubmit anything.

#48

gullfo wrote:the live room will have different characteristics than the critical listening room... depending on the ceiling structure of the live room, you could leverage the ceiling-wall "corners" for a large soffit which provides routing for hvac, absorption, lighting etc. imho, the small "trap" you would have in the live room would be inconsequential compared to have that additional space in the control room.

updated floor plan.

#49

coolio. will be much easier to build, and you have some space on either side of the door into live room to place absorbers. plus another on opposite walls of the entry door and the cr door.

#50

This basically the same thing I came up with for my room, I think my space is bigger though

#51

Hi All!

Would love some feedback on treatment design. While I recoup financially from where I got to today, Im spending a little time thinking through the next phase after the build is complete. My goal for the control room is to have it equal parts critical listening, but also leaving a portion of the room a little lively for acoustic guitars of vocals. So in this mock, I have treated the front half with deep corner traps, and a nice soffit trap that goes all the way around the room.

The soffit is 12 inches tall, by 16 inches wide and will be stuff with rockwool. The ceiling cloud is about 8'x10' trapezoidal and will be 4" deep and 3" off the ceiling to account for LED lighting that I will be putting on top. The 2x4 panels scattered throughout are 2" panels made with 703.

Not sure what kind of feedback im looking for other than I am going in the right direction and how to keep the back of the room both controlling some of the bass modes and being a "alive" for vocals or acoustic guitars....

#52

Would love some feedback on treatment design.

My goal for the control room is to have it equal parts critical listening, but also leaving a portion of the room a little lively for acoustic guitars of vocals.

It's fine (and doable) to have a CR that serves dual purposes, but that should not get in the way of the primary purpose of the room: It's a control room, after all. So that's what it should be, first and foremost! You also want to use for acoustic recording, so that's the secondary purpose, ut it should not get in the way of the room being as good as it can be for mixing. Thus, it should be set up as a control room, to do that job well, then also have some "stuff" that can be added/changed on-the-fly as needed to do the recording.

If you try to design a room to do both at once, you'll end up with a room that does neither well. Make it one or the other, then adapt as needed.

So, your goal should be to have your bass trapping where it is most needed, and where it can be most effective, which is in the rear of the room (behind your head as you sit at the mix position). The soffits should also be built as proper soffits, that do the job they are supposed to do. What soffits are "supposed to do", is multi-fold. BUt the most basic thing they do, is to extend the front baffle of the speaker outwards to much larger dimensions, which achieves most of "what a soffit is supposed to do". Is solves the front wall SBIR problem to a large degree, it solves the power imbalance issue, it solves the edge diffraction issue, it improves focus, tightens the sweet spot, extends the bass response, and pretty much is the best possible thing you can do for your room and your speakers, in pretty much any room, and for pretty much any speaker (with some exceptions, of course). A "soft" soffit cannot achieve most of that. It can help a little, yes, but it doesn't do the job that a soffit can do, when built right.

This implies that the soffit face must be solid, hard, massive, rigid, and extend outward around each speaker for as far as possible.

So in this mock, I have treated the front half with deep corner traps, and a nice soffit trap that goes all the way around the room.

Putting corner traps in as many corners as possible, is a good thing! Absolutely! But corner traps in the front corners of the room are less effective than traps in the rear corners.

Basically, when designing the room treatment, take the point of view of the speakers: Think about what you would "see" of the room, if your head were in the location and orientation of the speaker. What you see there, is where your first priority of treatment should be, because that's the first things your sound waves are going to hit. And what you see mostly from that perspective, is the rear wall, the side walls, and part of the ceiling. Since all of those surfaces are going to be the first ones to get hit by sound waves, and your goal is to achieve the "20-20 criteria", then those surfaces should be treated accordingly: Major absorption to "suck up" as much of possible of the unwanted energy that could reflect of those surfaces back to the mix position, combined with secondary treatment to prevent the primary treatment from doing the task too well and over-absorbing some frequencies, and perhaps tertiary treatment to provide a bit of diffusion, if appropriate for the room (usually not feasible in small rooms: only medium and large rooms are real candidates for extensive diffusion).

Here, to, a proper soffit simplifies things: Your perspective as "my head is a speaker" is simpler if you don't have to worry about turning your eyes sideways, to figure out edge-diffraction, and don0't have to turn them around backwards, to figure our front-wall SBIR. With soffits, your full attention can be focused on your normal field of view, which is what the speaker "sees". The angle of view could change a bit, depending on the specific speaker you plan to use, and that will lead you in designing the most appropriate treatment for the side walls and ceiling. Some speakers have wider dispersion in certain frequency ranges, so consider that when you do this "my head is the speaker" trick.

This is a simple approach, but it will get you a long way to designing the most important treatment for the room.

If you do that, you'll find that you end up with a room that is mostly "hard" at the front (but with "soft" traps hidden inside, behind those hard front surfaces), and mostly "soft" at the back, with massive amounts of absorption (but tempered with some carefully placed and carefully targeted reflective surfaces, so as not to lose the high end, and keep things balanced.

The soffit is 12 inches tall, by 16 inches wide and will be stuff with rockwool.

I'm assuming that you mean the hard front baffle of the soffit? If so, that's rather small. I generally design soffits to run from floor to ceiling, with some open areas close to the floor and ceiling to expose the inner treatment to the room. So in a typical home studio conversion where the ceiling is at 8 feet, I'd leave a foot open near the floor and maybe two feet near the ceiling. Thus, the actually soffit baffle would be around 6 feet high.

Likewise in the horizontal direction: the general rule is that the soffit baffle should be at least three times the diameter of your low-frequency driver. So if you have a speaker with an 8" woofer, then you want the soffit baffle to be at least 24" (60cm) wide. Wider is better. An even more solid "rule of thumb" is simply that the baffle should be at least a 1/4 wavelength of the lowest frequency that the speaker will produce. That's hard to do in the majority of rooms! But it's a good goal to keep in mind, and will put at the forefront the basic need to make it as wide as you possibly can.

The ceiling cloud is about 8'x10' trapezoidal and will be 4" deep and 3" off the ceiling to account for LED lighting that I will be putting on top.

Clouds are good. Deep clouds are better. Angled clouds are better still (higher above your head, lower towards the speakers), and hard-backed clouds are even better yet! Shape isn't that important, so you can shape it any way you think looks good, but do make sure that it completely covers the first reflection points up there, and also covers the areas that could be sending too many unwanted reflections towards the back wall, side walls, or rear floor. This might help: [url=https://digistar.cl/Forum/viewtopic.php?f=9&t=2&p=2Raytracing assistant for Sketchup, for visualizing speaker dispersion[/url]

The 2x4 panels scattered throughout are 2" panels made with 703.

Are they strategically located at the first-reflection points for the mix position? Do they completely cover those points? Also, in general it's better to have treatment panels of differing depth and differing wall gaps, to avoid over-treating one specific frequency band. Many rooms end up with a "death valley" in their time-domain responses somewhere in the region of 150Hz to 500 Hz for this very reason: Overt-treatment with 4" deep traps. Make some of them 6" deep, or vary the air gap behind them, or angle them, or something! To make sure that you are not killing one part of the spectrum at the expense of another part.

am going in the right direction and how to keep the back of the room both controlling some of the bass modes and being a "alive" for vocals or acoustic guitars....

Everything I've said above is pretty much the opposite of what you'd need at the back of the room for acoustic tracking! Because it is what a Control Room needs, on order to function as a Control Room.

So what to do? The first thing you could do is to flip your tracking perspective! Since acoustic instruments sound better (and track better) with a bit of "life" in the room, then do the tracking towards the front of the room, where there is life. Since the entire front will be mostly reflective (large, solid, rigid, hard surfaces), you already have what you need up there: But mostly people do ti backwards! What's important here is what the mic sees, not so much what you see. So if you set up your acoustic guitarist facing the front of the room, with the mic in front of him facing the rear, then he will hear nice warm reflections coming back to his head from the front of the room, but the mic won't! The mic will be facing the totally dead rear wall. So angle your setup! Have the musician face one of the side walls, where there isn0t too much absorption, with his back facing another side wall, and the mic set up judiciously so it "sees" that side wall, and perhaps even some of the front of the room. Bingo! You get a better-sounding recording, and the musician also gets a decent sounding-room acoustic. It's not ideal, of course, but it can work. Experiment to find the best locations, orientations, and mic setups. This also applies to vocals and other acoustic instruments too: If you play around a bit with different spots / mics / angles, you will likely find usable arrangements for many scenarios: The key here is to do the opposite of the "my head is a speaker" trick, and do the "my head is the mic" trick: put your head in the potential mic spot, look in the direction it will be facing, and see what is "out there" in that direction. "Hard surfaces" imply brighter, livelier. "Soft" surfaces imply duller, more muted.

If that still doesn't do what you want, then there's another way of doing it: Variable acoustics. Build treatment that can changed on the fly to meet your needs. Surfaces that can be flipped, rotated, slid, opened, closed, or moved in some way, to change the acoustic response of the room. It might be as simple as having a couple of gobos stored outside the room in a closet, that you bring in for tracking or take out for mixing. Or it might be something more sophisticated, built into the room itself, like this: Variable acoustics devices: adjustable room response at will

So there's a few ideas that you might find helpful, with planning the treatment for your room! The basic advice I can offer is to build at for it's primary purpose: Control Room. Then treat it for the secondary purpose (tracking room) but in such a way that it does not interfere with the primary purpose.

- Stuart -

#53

Soundman2020 wrote:Source of the post
Would love some feedback on treatment design.

My goal for the control room is to have it equal parts critical listening, but also leaving a portion of the room a little lively for acoustic guitars of vocals.
It's fine (and doable) to have a CR that serves dual purposes, but that should not get in the way of the primary purpose of the room: It's a control room, after all. So that's what it should be, first and foremost! You also want to use for acoustic recording, so that's the secondary purpose, ut it should not get in the way of the room being as good as it can be for mixing. Thus, it should be set up as a control room, to do that job well, then also have some "stuff" that can be added/changed on-the-fly as needed to do the recording.

If you try to design a room to do both at once, you'll end up with a room that does neither well. Make it one or the other, then adapt as needed.

So, your goal should be to have your bass trapping where it is most needed, and where it can be most effective, which is in the rear of the room (behind your head as you sit at the mix position). The soffits should also be built as proper soffits, that do the job they are supposed to do. What soffits are "supposed to do", is multi-fold. BUt the most basic thing they do, is to extend the front baffle of the speaker outwards to much larger dimensions, which achieves most of "what a soffit is supposed to do". Is solves the front wall SBIR problem to a large degree, it solves the power imbalance issue, it solves the edge diffraction issue, it improves focus, tightens the sweet spot, extends the bass response, and pretty much is the best possible thing you can do for your room and your speakers, in pretty much any room, and for pretty much any speaker (with some exceptions, of course). A "soft" soffit cannot achieve most of that. It can help a little, yes, but it doesn't do the job that a soffit can do, when built right.

This implies that the soffit face must be solid, hard, massive, rigid, and extend outward around each speaker for as far as possible.

So in this mock, I have treated the front half with deep corner traps, and a nice soffit trap that goes all the way around the room.
Putting corner traps in as many corners as possible, is a good thing! Absolutely! But corner traps in the front corners of the room are less effective than traps in the rear corners.

Basically, when designing the room treatment, take the point of view of the speakers: Think about what you would "see" of the room, if your head were in the location and orientation of the speaker. What you see there, is where your first priority of treatment should be, because that's the first things your sound waves are going to hit. And what you see mostly from that perspective, is the rear wall, the side walls, and part of the ceiling. Since all of those surfaces are going to be the first ones to get hit by sound waves, and your goal is to achieve the "20-20 criteria", then those surfaces should be treated accordingly: Major absorption to "suck up" as much of possible of the unwanted energy that could reflect of those surfaces back to the mix position, combined with secondary treatment to prevent the primary treatment from doing the task too well and over-absorbing some frequencies, and perhaps tertiary treatment to provide a bit of diffusion, if appropriate for the room (usually not feasible in small rooms: only medium and large rooms are real candidates for extensive diffusion).

Here, to, a proper soffit simplifies things: Your perspective as "my head is a speaker" is simpler if you don't have to worry about turning your eyes sideways, to figure out edge-diffraction, and don0't have to turn them around backwards, to figure our front-wall SBIR. With soffits, your full attention can be focused on your normal field of view, which is what the speaker "sees". The angle of view could change a bit, depending on the specific speaker you plan to use, and that will lead you in designing the most appropriate treatment for the side walls and ceiling. Some speakers have wider dispersion in certain frequency ranges, so consider that when you do this "my head is the speaker" trick.

This is a simple approach, but it will get you a long way to designing the most important treatment for the room.

If you do that, you'll find that you end up with a room that is mostly "hard" at the front (but with "soft" traps hidden inside, behind those hard front surfaces), and mostly "soft" at the back, with massive amounts of absorption (but tempered with some carefully placed and carefully targeted reflective surfaces, so as not to lose the high end, and keep things balanced.

The soffit is 12 inches tall, by 16 inches wide and will be stuff with rockwool.
I'm assuming that you mean the hard front baffle of the soffit? If so, that's rather small. I generally design soffits to run from floor to ceiling, with some open areas close to the floor and ceiling to expose the inner treatment to the room. So in a typical home studio conversion where the ceiling is at 8 feet, I'd leave a foot open near the floor and maybe two feet near the ceiling. Thus, the actually soffit baffle would be around 6 feet high.

Likewise in the horizontal direction: the general rule is that the soffit baffle should be at least three times the diameter of your low-frequency driver. So if you have a speaker with an 8" woofer, then you want the soffit baffle to be at least 24" (60cm) wide. Wider is better. An even more solid "rule of thumb" is simply that the baffle should be at least a 1/4 wavelength of the lowest frequency that the speaker will produce. That's hard to do in the majority of rooms! But it's a good goal to keep in mind, and will put at the forefront the basic need to make it as wide as you possibly can.

The ceiling cloud is about 8'x10' trapezoidal and will be 4" deep and 3" off the ceiling to account for LED lighting that I will be putting on top.
Clouds are good. Deep clouds are better. Angled clouds are better still (higher above your head, lower towards the speakers), and hard-backed clouds are even better yet! Shape isn't that important, so you can shape it any way you think looks good, but do make sure that it completely covers the first reflection points up there, and also covers the areas that could be sending too many unwanted reflections towards the back wall, side walls, or rear floor. This might help: [url=https://digistar.cl/Forum/viewtopic.php?f=9&t=2&p=2Raytracing assistant for Sketchup, for visualizing speaker dispersion[/url]

The 2x4 panels scattered throughout are 2" panels made with 703.
Are they strategically located at the first-reflection points for the mix position? Do they completely cover those points? Also, in general it's better to have treatment panels of differing depth and differing wall gaps, to avoid over-treating one specific frequency band. Many rooms end up with a "death valley" in their time-domain responses somewhere in the region of 150Hz to 500 Hz for this very reason: Overt-treatment with 4" deep traps. Make some of them 6" deep, or vary the air gap behind them, or angle them, or something! To make sure that you are not killing one part of the spectrum at the expense of another part.
am going in the right direction and how to keep the back of the room both controlling some of the bass modes and being a "alive" for vocals or acoustic guitars....
Everything I've said above is pretty much the opposite of what you'd need at the back of the room for acoustic tracking! Because it is what a Control Room needs, on order to function as a Control Room.

So what to do? The first thing you could do is to flip your tracking perspective! Since acoustic instruments sound better (and track better) with a bit of "life" in the room, then do the tracking towards the front of the room, where there is life. Since the entire front will be mostly reflective (large, solid, rigid, hard surfaces), you already have what you need up there: But mostly people do ti backwards! What's important here is what the mic sees, not so much what you see. So if you set up your acoustic guitarist facing the front of the room, with the mic in front of him facing the rear, then he will hear nice warm reflections coming back to his head from the front of the room, but the mic won't! The mic will be facing the totally dead rear wall. So angle your setup! Have the musician face one of the side walls, where there isn0t too much absorption, with his back facing another side wall, and the mic set up judiciously so it "sees" that side wall, and perhaps even some of the front of the room. Bingo! You get a better-sounding recording, and the musician also gets a decent sounding-room acoustic. It's not ideal, of course, but it can work. Experiment to find the best locations, orientations, and mic setups. This also applies to vocals and other acoustic instruments too: If you play around a bit with different spots / mics / angles, you will likely find usable arrangements for many scenarios: The key here is to do the opposite of the "my head is a speaker" trick, and do the "my head is the mic" trick: put your head in the potential mic spot, look in the direction it will be facing, and see what is "out there" in that direction. "Hard surfaces" imply brighter, livelier. "Soft" surfaces imply duller, more muted.

If that still doesn't do what you want, then there's another way of doing it: Variable acoustics. Build treatment that can changed on the fly to meet your needs. Surfaces that can be flipped, rotated, slid, opened, closed, or moved in some way, to change the acoustic response of the room. It might be as simple as having a couple of gobos stored outside the room in a closet, that you bring in for tracking or take out for mixing. Or it might be something more sophisticated, built into the room itself, like this: Variable acoustics devices: adjustable room response at will

So there's a few ideas that you might find helpful, with planning the treatment for your room! The basic advice I can offer is to build at for it's primary purpose: Control Room. Then treat it for the secondary purpose (tracking room) but in such a way that it does not interfere with the primary purpose.

- Stuart -

Thank you Stuart! All amazing advice. I will work on building it as a critical listening room first, and a tracking space as permits. Given all the great advice about positioning the artist, it might not be as hard as I thought.

and hard-backed clouds are even better yet!

When you mention hard back, do you mean something like plywood or MDF as the backing material of the cloud? so from the "top" down I would have my ceiling -> an air gap -> plywood/mdf -> rockwool -> fabric wrap.

I just want to make sure I am understanding right that the cloud having a layer of mass on top before the airgap and my raw ceiling is what you meant.

#54

eightamrock wrote:Source of the post When you mention hard back, do you mean something like plywood or MDF as the backing material of the cloud? so from the "top" down I would have my ceiling -> an air gap -> plywood/mdf -> rockwool -> fabric wrap.

Right! That's the idea. And after you have angled it, there will probably be space on top of the hard-back where you could put in some more insulation, just resting there. Helps a little with a few minor issues up there.

Also, any time you have insulation hanging overhead, it's a good idea to have some thin plastic below that (between the insulation and the fabric), for two reasons: 1) In case the insulation starts shedding fibers over time, so they don't get into your gear (or you!), and 2) It helps to avoid over-absorbing the high end, since the plastic will reflect back some of the highs, at frequencies above a certain point that is governed by the thickness of the plastic.

The second reason above also applies to other absorption you have in the room (rear wall bass traps, for example). You can sort of "tune" the absorption range a little like that, by using the right thickness of plastic in the right locations. If you figure that the plastic would have to be crazy thick to target the frequencies you want, then use wood slats instead, across the front of the fabric. The width of the slats is also a factor in what frequency range they reflect best.

However, for the rear wall, do be careful with angles! You don't want to have hard reflections getting back to your ears at the mix position. For the rear wall traps, I normally leave the section of absorption around ear height relatively clear (a couple of feet up and down from ear height), and only put plastic higher and lower than that. For the ceiling, you should be OK anyway, since the tilted angle of the cloud should keep reflections away from your head.

Regarding fabric: It's also a good idea to put a layer of cheap black cloth up first, then your more expensive finish fabric over that. The reason being that with many finish fabrics, you can see through it to a certain extent at some angles and under some lighting conditions. The cheap black fabric helps to block the view, so you don't see all the ugly interior or your bass traps! Any type of thin, cheap black cloth will so, with small threads and a tight weave. For all of your fabric, check that it is "breathable" before you buy! Put a piece over your mouth and nose, and see if you can breathe reasonably easily, with not too much resistance. The sound needs to get through that fabric in order to be treated, and if it is not "breathable" then there's an acoustic impedance issue going on. Sometimes you can use that to good effect, as part of the treatment design, but in general you don't want fabric that is hard to breathe through.

- Stuart -

#55

Hi eightamrock,

Thanks for sharing this detailed post of yours. Has your build been completed by now?

I'd like to ask you, which software did you use for this visualization of the studio? Is that CAD? I'm currently working with a software called Planner5D, which is easy to use, but it also has a lot of limitations. I'm, unfortunately, under a good amount of time pressure until the contractor I'm working with needs to start the build. Hence, I don't think I'd be able to dedicate a big amount of time to learning the software. I also have no budget to consult a studio designer to help me create the concept + plans. It's a DIY project mostly.

If this is CAD, how long did it take you to learn it for the purposes of this illustration? Alternatively, I'm thinking of continuing to use Planner5D for a basic 2D and 3D model of the space without dimensions indicated. But then I'll sketch up images of the different components in Canva in a 2D view with some text, arrows, numbers, explanations, etc.

Thanks and have a good day,
Ferdinand

#56

his drawings are done using Sketchup. there is a free web based version as well as (pricey) paid versions. the main differences are: the pro (or studio) version can run on the desktop (PC or Mac) and support "extensions" (Ruby based scripts which do many things) and "dynamic components" (SU components which can use parameters to change themselves - like a wall frame etc). the free web version cannot use extensions or dynamic components.

like the game of Go - easy to learn, a lifetime to master (or at least some effort spent really learning it...)

you start with a floor plan in 2D. it uses full scale. then add wall thickness and "pull" up the wall. then add doors, windows etc and make it into a group (your template). from there you can add and remove things to try them out. there is a 3D warehouse full of stuff - beware some of it is not done so well so read up descriptions (like size :-)

) before loading into your model.

there are a number of decent quality videos on how to use Sketchup online to get you up to speed.

#57

Thanks for your response, Glenn. I've installed the SketchUp desktop app (I have a free 30 day trial which I'll probably let itself turn into a subscription). I found a great channel on YouTube that gives a good introduction to it. I haven't been able to wrap my head around efficient grouping yet, but I'm sure I'll get there. Cheers

#58

I am now faced with a new problem! I had originally designed the room so that the mini split head was on the back wall. Due to an issue I had not anticipated, I can not put a hole big enough in the top plate running up to the attic to house the linesets without compromising the structural member.

That said my options are now to either put the head on the front wall centered above the mix position, or a side wall. Im tempted to put it above the entry door tucked into the soffit and run the lineset and condensate pipe in the soffit and out the back wall. Originally I was going to run the line set up into the attic over and out. The condenser is located behind the wall the red arrow is pointing to.

Do I have any other options? The easiest and what my AC guy wants to do is put it on that front wall above my mix position, but I understand having any airflow there is "bad"... though I have seen it done.

#59

Due to an issue I had not anticipated, I can not put a hole big enough in the top plate running up to the attic to house the linesets without compromising the structural member.

Does it have to go in that location, where you would need to run the lines through the top plate? Maybe it would be possible to move it slightly, such that the lines can go through somewhere else.

Also, since you say that the lines are going to run "up" to the attic, that sounds like a problem! Red flag! One of those lines that you have to run, is the condensate drain, and in most situations it cannot run "up". It needs to slope only downwards from the point where it leaves the back of the unit, to the point where it actually drains. That is usually a gravity line, where the condensate water just runs downhill, all the way. It can't run "up" at all. Worst case, it can run flat, but only for a short distance. In general, it needs to run downhill.

The only exception are some units that have a built-in sump and condensate pump to push the condensate, or if you design your system with an external accessory pump that does that. But even then, the unit itself needs to be designed for that, or installed in such a way that the condensate can initially run down to the pump, then be moved upwards from there. The point where that pipe connects to the back of your unit is very often the back of the condensate tray, that catches the condensate water as it drips down from the coils inside. If you have that pipe running upwards, then the condensate will accumulate in the tray with nowhere to go, and soon run over, spilling water inside your unit, and down the wall.

So, if your drain would be running up, and you don't have a system with a condensate pump, then there's a big problem that needs to be fixed. You would need to redesign the system such that all of your pipes follow a downward path initially, not upwards.

Normally, the bundle of pipes and wires coming out the back of your unit just run straight through the inner-leaf of your wall, into the cavity between the inner and outer leaf. There, you bend them around to run downwards through the cavity for a while, then bend them again (gently!) to exit through the outer wall. You should try to avoid taking them straight through both leaves at once, since that creates a flanking path, along with two penetrations close to each other (one in each leaf). That's a weak point for acoustic isolation.

Now, maybe I misunderstood what you were saying, but from your comment it seems there's an issue with the way you were planning to install your min-split. There should never be a need to take the pipe and wiring bundle straight up through the top plate.

- Stuart -

#60

Soundman2020 wrote:
Due to an issue I had not anticipated, I can not put a hole big enough in the top plate running up to the attic to house the linesets without compromising the structural member.
Does it have to go in that location, where you would need to run the lines through the top plate? Maybe it would be possible to move it slightly, such that the lines can go through somewhere else.

Also, since you say that the lines are going to run "up" to the attic, that sounds like a problem! Red flag! One of those lines that you have to run, is the condensate drain, and in most situations it cannot run "up". It needs to slope only downwards from the point where it leaves the back of the unit, to the point where it actually drains. That is usually a gravity line, where the condensate water just runs downhill, all the way. It can't run "up" at all. Worst case, it can run flat, but only for a short distance. In general, it needs to run downhill.

The only exception are some units that have a built-in sump and condensate pump to push the condensate, or if you design your system with an external accessory pump that does that. But even then, the unit itself needs to be designed for that, or installed in such a way that the condensate can initially run down to the pump, then be moved upwards from there. The point where that pipe connects to the back of your unit is very often the back of the condensate tray, that catches the condensate water as it drips down from the coils inside. If you have that pipe running upwards, then the condensate will accumulate in the tray with nowhere to go, and soon run over, spilling water inside your unit, and down the wall.

So, if your drain would be running up, and you don't have a system with a condensate pump, then there's a big problem that needs to be fixed. You would need to redesign the system such that all of your pipes follow a downward path initially, not upwards.

Normally, the bundle of pipes and wires coming out the back of your unit just run straight through the inner-leaf of your wall, into the cavity between the inner and outer leaf. There, you bend them around to run downwards through the cavity for a while, then bend them again (gently!) to exit through the outer wall. You should try to avoid taking them straight through both leaves at once, since that creates a flanking path, along with two penetrations close to each other (one in each leaf). That's a weak point for acoustic isolation.

Now, maybe I misunderstood what you were saying, but from your comment it seems there's an issue with the way you were planning to install your min-split. There should never be a need to take the pipe and wiring bundle straight up through the top plate.

- Stuart -

Thanks for the reply, yes the plan was to always use a pump to get the condensate out. That was part of the system design because we knew it had to go up.

The issue is I can’t drill a hole in the top plate of the wall assembly because the double 2x6 plate is acting as a tension member for the roof. If I put 2.5” hole in it that’s more than the 30% allowable by code.

The reason to run line set up or inside the soffit is because of where the condenser is. It’s on the opposite side of the building.

So original plan was put the head on the opposite side of the building from where the condenser is, this was fine with a longer line set and condensate pump. But now I can’t put the line set in the wall because I can’t exit it out of the original location. So it’s move the head so it’s on the same side as the condenser or run the lines through the soffits.

Make sense?

Soundman2020 - Studio Design Forum