Stand Alone Studio Build

[Murray]

Studio Construction.pdf

Hi Everyone,

This is my first post to this forum but before I go on I'd like to thank everyone for their contributions. I've found this a great place to confirm or debunk a number of suggestions that I've had from people I've been dealing with along this journey.
Am just learning as I'm going with this build and appreciate any feedback and comments to help me get it as right as possible with the budget I have for construction.


Overview
I'm building a small stand alone studio in my small backyard that I want to use for recording, mixing and playing various instruments (loud guitars, vocals, percussion, keyboards) it won't be big enough for drums.
Have attached a Google Maps view of my property. The studio will sit underneath the trees to the rear of the property. As you can see, neighbours are close, trees overhead and underneath occasional flight path.
I'm trying to achieve somewhere around 63db attenuation/isolation. No idea exactly how loud I am becauee I can't make any noise until the studio is finished. I will be loud!

Budget:
I would like to get away with spending around $20,000 (AUD) for the construction (excluding treatment) but can stretch it further if need be.

Basic construction:

- Concrete Slab
- Double wall two leaf timber stud construction
- Single pitch skillion roof

Dimensions:
Internal dimensions (wall face to face & ceiling/floor face to face)
Sepmeyer 2 Ratio 1: 1.28 1.54
Height = 2500mm
Width = 3200mm
Length = 3850mm
m2 = 12.32
m3 = 30.8


I've found it easier to write a document covering everything that's been scoped and worked on to date with the intention of providing this to builders for quoting and construction.
Hope I'm not being rude by asking people to refer that attached document rather than re-writing it here.
It's a work in progress at the moment so please excuse the notes to myself throughout.
I had to mess with the image quality to reduce the file size for posting. Hope it's still ok.


I'm currently trying to decide on equipment placement within the room with respect to the window and door. Have two options (so far) and was hoping to get some feedback from you all on the following points. I have attached a basic visio diagram (just started learning sketchup this week) showing the placement of doors and windows. Room and equipment are to scale.

- When mixing will I have any issues with reflections by placing the window as shown in the diagram? The window size will approx 1.2m long x 0.8m wide.
- Would be great to get some feedback on the placement of the mixing desk and main monitors for options 1 & 2. I realise pointing the monitors down the long length of the room will give better bass frequency response but I'm interested to hear if the other placement option will be significantly worse. I have a lot of gear to cram into this room and need to consider functionality almost as much as response.

Thanks for reading.

Cheers

Murray

[Soundman2020]

Hi Murray, and Welcome!

I'm trying to achieve somewhere around 63db attenuation/isolation.

Why such a strange number? Nothing wrong with that, of course, but why so precise? Why not 60 or 65? 63 just seems strange...

No idea exactly how loud I am becauee I can't make any noise until the studio is finished. I will be loud!

Even more reason why 63 sounds so strange! You don't know how loud you are, but you do know you need exactly 63? I'm guessing that you saw a diagram someplace that showed a wall capable of STC-63, or something like that?

Have attached a Google Maps view of my property.

... looking, but not seeing.... I think you forgot to attach that.

I'm currently trying to decide on equipment placement within the room with respect to the window and door. Have two options

Definitely option 1.

- When mixing will I have any issues with reflections by placing the window as shown in the diagram?

Probably not. It seems that the reflections will be coming form just in front of the window. However, the only way to be certain is to ray-trace.

I realise pointing the monitors down the long length of the room will give better bass frequency response

Not really. There's no reason why the speakers would perform better like that. The reason for pointing the speakers down the long axis is not related to bass response at all: it is related to Haas time, which is the time it takes your ears and brain to integrate sounds. If you hear a sound and it's reflection within about 20ms of each other, then your brain did not have time to figure out that the second sound was actually a separate and distinct reflection of the first: instead, it thinks that the second sound was part of the first, and uses the comb-filtering, phase difference, and arrival-times to come to the conclusion there was only one sound that came from a different direction than where it really came from, and had a different frequency response... In other word, the psycho-acoustic perception of the sound is wrong, and you don't hear what is really there. If the reflection arrives more than about 20ms after the direct sound, your brain can figure all this out, and it is not fooled any more. It knows that the first sound is the one-and-only original, and it correctly identifies the source angle and frequency response, and it also knows that the second was an ambient reflection of the same sound, but not part of it.

That's why you want the rear wall as far back as possible: so that the reflections coming from it arrive late enough to give your brain a chance to interpret the direct sound properly. If the rear wall is too close, it screws up your perception of where the sounds are coming from, and their frequency response.

So you need a difference in path length of about 6m: the first reflection that reaches your ears must have taken a path that is 6m longer than the direct sound. That implies that the rear wall needs to be at least 3m behind your head. That's impossible with Option 2, and almost-but-not-quite doable with Option 1. I would make the room longer.

There are also other factors involved, but that's one of the big ones.

but I'm interested to hear if the other placement option will be significantly worse.

Yep. See above...

I have a lot of gear to cram into this room and need to consider functionality almost as much as response.

Well, I can't agree with that. The very purpose of building a studio is to hear accurate, clean sound so that you can produce mixes that translate. If you clutter up the room with a lot of gear, then you wont get that. It will become nothing but an equipment storage room that happens to have a couple of speakers and a console in it, but it won't be a studio. It won't be possible to mix well in there, and your mixes won't translate. One of the major issues with both of your layouts is the total lack of bass trapping. That's a small room, so it will need lots of bass trapping, but the only places where bass trapping can go are taken up with gear. So your room will have terrible bass response, major SBIR issues, modal issues, and other big problems. Even though you are choosing a good ratio for your dimensions, you still need bass trapping to damp those modes, and you need lots of it.

I would suggest that either you make the room big enough to fit in everything that you need, or you add a small machine room next to it where you can put most of the gear.

There are also issues with the way you have your geometry set up: you need to get your speakers off the desk and onto stands behind the desk. That's a big issue, right there. Having speakers on the desk or meter bridge produces comb filtering and coloration of the sound, due to the reflections from the desk and the vibrations in the desk. You cannot get clean sound from your speakers to your ears like that. Your room will not tell the truth, and your mixes will suffer.

My suggestion would be to make the room bigger, for three reasons: 1) So you can have enough distance between your head and the rear wall, 2) so you can have enough space to fit in all your gear, and 3) so you can have enough space to fit in the bass trapping that you will most definitely need.

- Stuart -

[Murray]

Hi Murray, and Welcome!

Thanks Stuart

I'm trying to achieve somewhere around 63db attenuation/isolation. No idea exactly how loud I am becauee I can't make any noise until the studio is finished. I will be loud!

Even more reason why 63 sounds so strange! You don't know how loud you are, but you do know you need exactly 63? I'm guessing that you saw a diagram someplace that showed a wall capable of STC-63, or something like that?

Spot on. I've received some construction details for walls with various db ratings. The information doesn't actually state if this is STC.
Building a double two leaf timber stud wall with 75mm white thermal batts in the outer wall. I can't make the structure any more dense than that so whatever attenuation I get from that spec is what I have to live with. I didn't say exactly 63db.

Have attached a Google Maps view of my property.

... looking, but not seeing.... I think you forgot to attach that.

It's attached to the original post. Just above the visio diagram. Had to muck around for ages to get attachments small enough to post.

I'm currently trying to decide on equipment placement within the room with respect to the window and door. Have two options

Definitely option 1.

Thanks for the confirmation.

- When mixing will I have any issues with reflections by placing the window as shown in the diagram?

Probably not. It seems that the reflections will be coming form just in front of the window. However, the only way to be certain is to ray-trace.

Alright. I'll look into working out how to do some ray tracing.
Could you suggest any resources/cheapish software?

So you need a difference in path length of about 6m: the first reflection that reaches your ears must have taken a path that is 6m longer than the direct sound. That implies that the rear wall needs to be at least 3m behind your head. That's impossible with Option 2, and almost-but-not-quite doable with Option 1. I would make the room longer.

Thanks for the info on the Haas Effect.
I've attached a couple of re-worked Visio diagrams with larger room ratios. Hopefully I can get away with Louden 1 as the Sepmeyer 3 is probably out of the question.

I have a lot of gear to cram into this room and need to consider functionality almost as much as response.

Well, I can't agree with that. The very purpose of building a studio is to hear accurate, clean sound so that you can produce mixes that translate. If you clutter up the room with a lot of gear, then you wont get that. It will become nothing but an equipment storage room that happens to have a couple of speakers and a console in it, but it won't be a studio. It won't be possible to mix well in there, and your mixes won't translate.

Understood.

One of the major issues with both of your layouts is the total lack of bass trapping. That's a small room, so it will need lots of bass trapping, but the only places where bass trapping can go are taken up with gear. So your room will have terrible bass response, major SBIR issues, modal issues, and other big problems. Even though you are choosing a good ratio for your dimensions, you still need bass trapping to damp those modes, and you need lots of it.

I'm still trying envisage how to treat the room. That's the main reason I haven't shown any bass traps in the diagram. I knew it would get pointed out!
I can do without the sofa bed. That gives more space to re-position the equipment to try and allow for bass traps. The racks can move further under the desk (argosy rack-n-roll style). Keyboard stand is A frame so potential to have a bass trap under that if needed.
On SBIR. My current monitors are modest Event TR8-XL's. From what I've just been reading online it seems I would be better served by placing these as close as possible to the front wall in order to raise the wavelength cancellation frequency so it can be treated more effectively.
Could you point me in the direction of some good bass trap resources? I really do have to read up this!
See updated diagrams attached.

I would suggest that either you make the room big enough to fit in everything that you need, or you add a small machine room next to it where you can put most of the gear.

As much as I would like. Unfortunately I cant add a machine room.

There are also issues with the way you have your geometry set up: you need to get your speakers off the desk and onto stands behind the desk. That's a big issue, right there. Having speakers on the desk or meter bridge produces comb filtering and coloration of the sound, due to the reflections from the desk and the vibrations in the desk. You cannot get clean sound from your speakers to your ears like that. Your room will not tell the truth, and your mixes will suffer.

Agree. Was planning to use speaker stands. Just didn't update the diagram to show this. Again see attached.
Is there any validity in using neoprene under the speakers to minimise transmision? Or is this a myth?

My suggestion would be to make the room bigger, for three reasons: 1) So you can have enough distance between your head and the rear wall, 2) so you can have enough space to fit in all your gear, and 3) so you can have enough space to fit in the bass trapping that you will most definitely need.

I wish I could make this room significantly bigger but I can't increase the dimensions very much.
Local council forced me to reduce room dimensions to comply with local regulations on land:dwelling ratios for our area.
My backyard is only approx 6.5m wide

I might be able to squeeze the length out slightly to:

Louden 1
Ratio 1: 1.4 1.9
Height = 2400mm
Length = 4560mm
Width = 3360mm
m2 = 15.32
m3 = 36.77

It's highly unlikely, but I could also try:

Sepmeyer 3
Ratio 1: 1.6 2.33
Height = 2400mm
Length = 5592mm
Width = 3840mm
m2 = 21.47
m3 = 51.53

Cheers

Murray

[Soundman2020]

Building a double two leaf timber stud wall with 75mm white thermal batts in the outer wall. I can't make the structure any more dense than that so whatever attenuation I get from that spec is what I have to live with.

The amount of isolation you will get depends on two things, basically: the surface density of each of the two leaves (mass), and the size of the gap between them. If you increase the density (by adding an extra layer of drywall, OSB, MDF, plywood, etc.) of one leaf, or both leaves, then the isolation goes up. If you make the air gap bigger, then the isolation goes up. And not only does the isolation go up, the resonant frequency goes down, so you get improved isolation in the lower end of the spectrum. The next biggest issue is the insulation inside the air gap. The more you have, the better the isolation is. Not because the insulation stops the sound going through, but because it acts as a damper on the multiple resonances going on inside the wall.

Implication: if you need to save space, you can use higher density materials! For example, fiber cement board is about twice the density of drywall, so you can get the same density in half the thickness. Or get higher density and reduce the air gap. Lead sheet is about ten times the density, so you could use one tenth the thickness. Of course, the down side is that high density materials are usually a lot more expensive... But if space is at a premium, and you can stretch your budget, then you can save a few inches (cm) here and there....

It's attached to the original post. Just above the visio diagram.

Ahhh! OK, now I see it. It would have been better to just insert it as a photo, directly in your thread, rather than a linked PDF.

Alright. I'll look into working out how to do some ray tracing.
Could you suggest any resources/cheapish software?

Unfortunately, this type of ray-tracing has to be done mostly manually. You draw a series of lines radiating out from the acoustic center of your speaker at various angles, then see where they go. When each line hits a wall, you shoot off a "reflected" line at the correct angle,and see where that goes. The "reflected" lines cannot go anywhere near the engineer's head. You need to keep them well away. There needs to be a sphere around his head that is at least a couple of feet in diameter, where no ray enters.

And you have to do this in 3D, not just 2D, because both the room and the sound inside it are 3D. SketchUp makes it reasonably easy to do that, but it is still a slow, tedious and boring process.

Hopefully I can get away with Louden 1 as the Sepmeyer 3 is probably out of the question.

There's no need to go crazy at trying to hit a specific ratio spot-on: As long as you are far away from the bad ratios, and reasonably close to one of the good ones, that's all you need.

I'm still trying envisage how to treat the room.

There are some basic "rules of thumb" that you can apply to most rooms, if they are reasonably shaped and sized. First and foremost is major bass trapping in as many corners as you can hit. The smaller the room, the more bass trapping you need. There are 12 corners in a normal rectangular room...

Next is treatment at the first reflection points (assuming that you are not doing an RFZ-style design). That includes both side walls and the ceiling.

Next is the front wall: you can deal with SBIR by placing absorption between the speakers and the front wall, assuming that the frequency is high enough.

Next is the rear wall: All of it needs to have thick, deep absorption on it, possible with some diffusion over that (if the room is big enough).

Finally, the side walls and the ceiling: absorption and/or diffusion (if indicated) and/or tuned traps as needed to get the decay times under control and smooth out the frequency response.

Then fine-tune as necessary to get within the usual specs, or at least as close as possible to them.

I can do without the sofa bed.

If the room can be a bit longer, you can still keep it.

The racks can move further under the desk (argosy rack-n-roll style).

You could also embed some of your gear in the top surface of the desk, at a suitable angle, and perhaps put it in "wing" modules out to the sides, similar to the desk in this room that I designed for one of my customers:

http://www.johnlsayers.com/phpBB2/viewt ... =2&t=20471

Of course, your room isn't that big, but the concept is there, and you might be able to borrow some ideas from that.

My current monitors are modest Event TR8-XL's. From what I've just been reading online it seems I would be better served by placing these as close as possible to the front wall in order to raise the wavelength cancellation frequency so it can be treated more effectively.

Yep! And yes. And !!!

Nice monitors, by the way. Once you decide on the final interior dimensions of the room I can figure out the optimum position and angles for those guys, as well as for your mix position.

Could you point me in the direction of some good bass trap resources? I really do have to read up this!

Sure! Right here!

http://www.johnlsayers.com/phpBB2/index.php

OK, I cheated: I linked you right back here to the forum itself.... Because it's about the best resource I know of for all aspects of studio design. (OK, so I'm a bit biased...)

There's a huge amount of info here on the forum about bass trapping, and many, many examples. It's just not so easy to find all of that, as the search feature here on the forum isn't fantastic... Personally, I love John's "acoustic hanger" concept for bass trapping. It is very effective, and easy to do. Another really good one is the "Superchunk" style bass trap. I use both of those extensively in my designs, and they both work very well: The room in the thread that I linked to above has both superchunks and hangers in it.

The problem with bass traps in small rooms is that they tend to suck out too much of the highs and mids, in addition to the lows, so you often need to cover the bass trap with plastic, or even wood slats in some cases, to keep the highs in the room and only absorb the lows. You can vary the thickness of the plastic, and the percentage coverage as needed to deal with the specific frequencies that are causing you problems.

As much as I would like. Unfortunately I cant add a machine room.

How about an isolated equipment cabinet? With all that gear around, I'm betting that some of it has fans in it (noisy), and that you don't need access to all of it all the time anyway. So you could put it inside a cabinet that isolates it acoustically while still providing sufficient cooling air flow. That could go on the other side of the desk, or behind the couch, for example...

Was planning to use speaker stands.

Excellent! Make them massively heavy (hollow steel filled with dry sand works well), and just the right height to get the acoustic axis of the speakers to 1.2m above the floor.

Is there any validity in using neoprene under the speakers to minimise transmision? Or is this a myth?

Not a myth: very true. You do not want the speaker transmitting sound or vibrations into the stand, which would then get into the floor, so you do need to decouple. Neoprene works OK, but I'm a big fan of Sorbothane for decoupling speakers. There really is nothing better.

I wish I could make this room significantly bigger but I can't increase the dimensions very much.

Could you make it a bit longer but not so wide? There are other good ratios for longer, narrower rooms... I'm assuming that there's a limit to the actual footprint (floor area) that you are allowed to have, so making it narrower would allow you to make it longer without affecting the total area. As I mentioned before, you don't need to go crazy on hitting a ratio perfectly: stay away from the bad ones, get somewhat close-ish to the good ones, and you'll be fine.

Also consider using higher density materials for the walls, to give you greater interior space. Just switching from two layers of 16mm drywall on each leaf to two layers of 8mm fiber-cement board, will save you 3cm in each room dimension...

Another option might be to build your inner-leaf walls "inside out": That's a technique invented by John, that save space on both isolation and treatment. I use that on many of my designs. It's a bit harder to build like that, but it does have its benefits.

- Stuart -

[Murray]

Hi Stuart,

There's no need to go crazy at trying to hit a specific ratio spot-on: As long as you are far away from the bad ratios, and reasonably close to one of the good ones, that's all you need.

Ok, I've been trying to squeeze out as much length as I can for the room.
I realised I had somehow got the dimensions of the mixing desk and other equipment in the room out of scale. Adjusted that and have more spare space which means the mixing position can be a little closer to the front wall.

This is pretty much my limit.

Is this a bad ratio?
1: 1.28 1.77

Height = 2500mm
Width = 3200mm
Length = 4430mm
m2 = 14.16
m3 = 35.44

How about an isolated equipment cabinet? With all that gear around, I'm betting that some of it has fans in it (noisy), and that you don't need access to all of it all the time anyway. So you could put it inside a cabinet that isolates it acoustically while still providing sufficient cooling air flow. That could go on the other side of the desk, or behind the couch, for example...

Yep planned on using an iso cab for the computer tower. The rest of it is actually pretty quiet. Couple of older (80's) rack synth modules hum a bit but they won't be on while I'm using mic's.

Have a lot of prep work coming up in the next few weeks to get to he initial construction stage.

Cheers

Murray

[Soundman2020]

which means the mixing position can be a little closer to the front wall.

Careful with that! You don't want to put your head in a modal null or peak... Having your ears at 1330 in a room 4430 long is about as close you want to go to the front wall. That's barely 30% of room depth (optimal is 38%). It will also mean that your speakers will need to be toed-in (angled inwards) a bit more steeply than usual. That's fine too, as long as you understand the consequences and can live with it. As long as you don't go past about 40-45° maximum toe-in, you are reasonably OK.

Is this a bad ratio?

See for yourself:
http://amroc.andymel.eu/?l=443&w=320&h= ... ing%20room

You can play around with the dimensions to see what changes what, but what you have there is reasonable. It's inside the Bolt area, and the Bonello chart is fairly smooth.


- Stuart -

[Murray]

Hi Stuart,

Thanks again for your response.
I had been playing around with the amroc calculator at times during the last couple of weeks and landed on:

Height 2.5 m
Length 4.30 m
Width 3.20 m

Studio Only - Correct Dimensions v5.jpg

Entering this into the calculator and comparing against my previous dimensions doesn't seem to change very much. It's actually just slightly further inside the bolt-area, the listening position is still pretty much 30% off the front wall and the bonello chart hasn't changed much (as far as I can tell).

So I will go with this unless you come back and highlight any major issue as a result of the change.

your speakers will need to be toed-in (angled inwards) a bit more steeply than usual. That's fine too, as long as you understand the consequences and can live with it

I expect a narrower/smaller sweet spot is the consequence. If there are others please let me know so I'm aware.
Can't really do too much about it but would like to know as much as I can

Ok next stop. Revise my HVAC and start looking into treatment.

Cheers

Murray

[Murray]

I've spent the last couple of weeks working on the ERV design for the studio.
Have decided on a unit that will deliver up to 120 l/s for a 35.7 cubic metre room.
The unit should give easily give me 6 air changes per hour. Must admit I struggled with the air change calculations.........

Attached a sketchup of my timber framing for the studio. It also shows the baffle box design and placement of the ERV & baffle boxes in the ceiling. I'm really short on space so my intention is to bring fresh air in through the ceiling and take stale air our through the ceiling with vents to the outside for fresh & stale air in the ceiling.

Would appreciate any feedback on the baffle boxes. I'm not really sure if there is a hard and fast design that needs to be adhered to for this to work effectively.

Studio Timber Structure v08.skp

Cheers

Murray

[Soundman2020]

Attached a sketchup of my timber framing for the studio.

Could you save that as an older version of SketchUp? At the location where I am right now, I only have access to an ancient computer that I can only install up to SketchUp V2013. The operating system can't handle more. So please save your model as something earlier, maybe even as V8 to be safe, and re-post. Then I'll take a look at it for you, and comment.


- Stuart -

[Murray]

Hi Stuart,

Could you save that as an older version of SketchUp?

Sure, here it is in Version 8.
Had to rar it. It was just over 500kbps

Studio Structure 2400 Ceiling in v08.rar

Have been through a bit since my last post.
Have got the gyprock and blue board (cladding) up.
Have left a copy of the baffle boxes on the ground so you can see them more easily.
I've grouped the gyprock and cladding together a little oddly (to make it easier to edit) so hopefully that wont be too difficult to work with.
I got a slightly better position in the bolt area by dropping the ceiling height from 2.5m to 2.4m and that also makes it easier to gyprock the room (less cutting).

Been too difficult to draw in ERV ducting so I've left it out as I know what I'm doing with that.
As before my intention is to go through the ceiling to exchange air and I will have the in/out vents on the side of the studio withing the ceiling cavity.
Will need to build an access door to maintain the ERV.

Will use a wall mounted Mitsubishi Split System for Air Con (again not shown yet)

Cheers

[Murray]

Bump

[Soundman2020]

Sure, here it is in Version 8.

Great! Looks pretty decent.

Have left a copy of the baffle boxes on the ground so you can see them more easily.

The duct liner inside your boxes is too thin: Standard duct liner is 1" thick, which is 25.4mm. Yours is only 16mm. You should increase that, then adjust the other dimensions of the box to keep the same internal cross sectional area.

I've grouped the gyprock and cladding together...

Fine, but it would be better to put everything on layers and name the layers, so it is easier to work with: that way you can turn layers on and off to see what's underneath/inside/behind very easily.

Been too difficult to draw in ERV ducting so I've left it out as I know what I'm doing with that.

YOU do, but the rest of us don't! It's not hard to put it in: just use a circle and extrude it with the "push/pull" tool. Copy with rotation as needed to make the path work. It doesn't need to be fantastically neat, as long as it shows the correct path and dimensions.

As before my intention is to go through the ceiling to exchange air

I'm not sure what you mean by that... Are you just talking about putting a plywood sleeve through the ceiling on the supply silencer, and another one on the return silencer, with registers on the ends?

Will need to build an access door to maintain the ERV.

Emmmm....Nope! Doors are huge gaping holes in your isolation shell, and therefor trash isolation! Unless you want to build your access panel the same way you build your main door, with a lot of mass and multiple full-perimeter seals, that's not a good plan.

- Stuart -

[Murray]

Hi Stuart,

Thanks for getting back to me.

The duct liner inside your boxes is too thin: Standard duct liner is 1" thick, which is 25.4mm. Yours is only 16mm. You should increase that, then adjust the other dimensions of the box to keep the same internal cross sectional area.

No probs. Thanks for letting me know. I'll make the changes.

Are you just talking about putting a plywood sleeve through the ceiling on the supply silencer, and another one on the return silencer, with registers on the ends?

Yeah that's what I meant. ERV & baffle boxes will be in the ceiling cavity (between the ceiling joists and rafters).
I didn't think about plywood sleeves but that sounds like a good idea.

Emmmm....Nope! Doors are huge gaping holes in your isolation shell, and therefor trash isolation! Unless you want to build your access panel the same way you build your main door, with a lot of mass and multiple full-perimeter seals, that's not a good plan.

I need to be able to get to the ERV to maintain it. Can't access it from within the inner room. So have to come in from the outside where I have enough space to get at the unit.
Was thinking about using full perimeter seals and treating the access door in a similar way to main doors. The size only needs about 1m x 600mm.

Not sure how else I can address the challenge.
If you have any advice that would be great.

Thanks for all your help. It has made a difference to the way I've put this together

Cheers

Murray

[Soundman2020]

I need to be able to get to the ERV to maintain it. Can't access it from within the inner room. So have to come in from the outside where I have enough space to get at the unit.
Was thinking about using full perimeter seals and treating the access door in a similar way to main doors. The size only needs about 1m x 600mm.

Not sure how else I can address the challenge.
If you have any advice that would be great.

I normally put Both the AHU (or fan) and the ERV (or HRV) outside of both the inner leaf and the outer leaf, where they can be easily accessed for service, maintenance, cleaning, repairs, replacement, etc. The silencers (baffle boxes) do indeed go inside the MSM cavity, but not the equipment. I try to keep the cavity between the two leaves sealed up completely, with nothing in there that needs access after the studio is finished. PM me if you want, and Ill send you some images from places that I have designed, showing how I normally do it.


- Stuart -