Building home studio on a roof terrace

[leandro]

Hi all,
I just discovered this forum a week ago and must said that I´m truly impressed with all the knowledge sharing happening in here. I´ve learned a quite lot already.

I live in Argentina (excuse mi if my English is not too good) and I´m planning to build a home studio on my roof terrace (6th floor of my building).
Not planning to record much in there. Mainly, its going to be used for mixing & mastering. I have a friend that is an architect, and he is going to take care of building it, but I´d like to give him the best information I could get to get a proper mixing room.

Just learned (kind of) to use sketchup. I´m attaching an image of the current roof terrace design/dimensions.
Here some explanations/considerations:
1- I will have the balcony/terrace of a neighbor very close, and I don´t want to disturb him. Also, his bedroom is behind the wall A.
2- Wall A is 3,26m tall. That´s my top limit for the roof.
3- Wall D is already a glass wall. So I guess i´ll have to think about making it a double glass wall. And also try to figure how to stop the reflections inside the room.
4- Room ratio might be a problem as it actually is. But as I have the intention to build a "box inside a box" (for isolation from my neighbor), and there is no roof yet, I could change it. I could also plan on making the walls and roof angled to avoid reflections, but not sure how much shoud I angle them (the glass one can´t be changed).

Hope I was clear enough. Any hints/considerations/pointers will be much appreciated.
Thanks!

[Gregwor]

Welcome and thank you for checking out the forum BEFORE building your space!

Room ratio might be a problem as it actually is. But as I have the intention to build a "box inside a box" (for isolation from my neighbor), and there is no roof yet, I could change it. I could also plan on making the walls and roof angled to avoid reflections, but not sure how much shoud I angle them (the glass one can´t be changed).

Unfortunately your room may never work well for mastering, but with careful design and a ton of acoustic treatment it may work for mixing. Here is why I say that:

ITU-R BS.1116-3 states the following:

8.2.2.1 Room size (floor area)
- For monophonic or two-channel stereophonic reproduction: 20-60 m2.

8.2.2.3 Room proportions
The following dimension ratios should be observed to ensure a reasonably uniform distribution of the low-frequency eigentones of the room:
1.1w/h less than or equal to l/h less than or equal to 4.5w/h – 4

where:
l : w : h :
length width height.

Additionally, the conditions l / h less than 3 and w / h less than 3 should apply.

8.5.1.2 Distance to the walls
For free standing loudspeakers, the distance of the acoustical centre of a loudspeaker from the surrounding reflecting surfaces should be at least 1 m.

I could go into more detail here, but as you can see, your room is very very small compared to the MINIMUM recommended size. You mentioned changing the inner room dimensions to make them more favourable with 8.2.2.3 Room proportions recommendations. That's great, as it will allow you to use space between your inner and outer leaf for HVAC silencer boxes however it will make your room dimensions even smaller. Granted, in studio design there are always trade offs, you unfortunately are starting off with serious limitations. Let's talk about your speaker distance to the walls and listening distance. Even if you left the room dimensions as is (which is literally a cube and the absolute WORST dimensional relationship for acoustics, your inner room would set you right around 3 meters. So, if we follow the rule of putting your speakers 1m from the walls, that means your speakers are only 1 meter apart. Not too cool.
The rear wall of your control room needs to have about 0.6m of insulation. Every corner of your room will also need large deep bass traps to make it sound any good. You'll also then need a tiny desk and chair plus any gear in there.

I know Stuart (Soundman2020 on here) has designed some TINY control rooms in the past so maybe he can chime in here. Like everyone on the forum, we are all working with spaces that we wish were bigger, but this is REALLY small.

Greg

[DanDan]

Isolation/Soundproofing is much more 'serious' than acoustic treatment.
Because of this, I would recommend that you analyse exactly how much noise needs to be block from where?
This 'blocking' will cause a thermal issue, which will also require pretty serious engineering to solve quietly.

DD

[leandro]

Thank you both for your replies.

Yesterday I realized that there is one thing I can make to make to room bigger:
The staircase that goes from my flat to the terraces is right behind the wall D. That staircase is 90cm wide and has 2 glass walls on each side (at terrace level). So the wall D (the glass one) could be moved 90cm back (and actually remove the current glass and just make a normal wall of it). This will make the room 90cm bigger in on direction, but the room will now include a staircase on it.

Not sure how a staircase would affect the room actually. It will make the room longer and also increase the height on that part. But what about the reflections on every step? How would that work? I feel it might be worse, but I might be wrong.

I´m attaching some real pictures in case it helps you to understand.
Thanks again!

[DanDan]

IMO bigger is better, almost always. In terms of Space, Visuals, and Building Regulations, your Architect is probably your best place to start.
Perhaps feed him/her some Acoustic generalities. e.g. Similar or Equal dimensions are troublesome. To build a fully Pro studio Newell needs a 4M ceiling height, and typically up to 60% of the room volume will end up as hidden soundproofing and treatment. That may sound extreme but it is quite real. In the new world of home working, ProSumer, many of us have to function in much smaller spaces. There are solutions such as the PSI Active Trap. Informed and perhaps encouraged by that, let's see how if he or she has questions and much space they can come up with in a realistic rough draft design.

DD

[leandro]

Ok, thanks a lot for your imput. I´m going to talk with my architect later about this new option.

What do you think about not making the walls parallel and/or making the roof "gabled"? (don´t know if gabled is the correct term in in English. I mean, not straight. Higher on one side of the room than in the other one). Would this inclinations of roof & walls may help at all with acoustics? Any degree of inclination may help, or should it be calculated?

Thanks again,

[DanDan]

Angling opposite boundaries by let's say 12 degrees or more will prevent flutter echo.
And again, bigger is better.
DD

[leandro]

I´ll start building in about 2 weeks. It will include the stairs, there won´t be a glass wall, and the walls and ceiling will have about 12 degrees.

Any other other tips will be off course very welcomed.

Thanks a lot!

[DanDan]

We would need to see some sort of plan in order to contribute acoustically.
It would not be a good idea to proceed without an acoustically informed design.
Generally the quality of reply you will get, will reflect the quality of the question.
DD

[leandro]

I don´t have any plans regarding acoustics after the construction so far.
During the construction, besides the soundproofing, the only changes I´m planing to make involving acoustics are the 12 degrees on the wall, and including the stairs so the room is not a perfect cube.
Not sure if there´s much I can do during the construction, or maybe I´m completely wrong on this?
I´m going to plan an acoustic treatment right after i finish building it.

Thanks again for your continuous help!

[Waka]

Hi Leandro,

Welcome to the forum!

In your situation you're unlikely to benefit from splayed walls (that is splaying the physical boundaries of your room), this is because you can't hang your walls off the edge of the building! So to splay them, you would be splaying them inwards and therefore reducing your room volume. Definitely don't reduce your room volume more. Reduce flutter echo with DIY panels applied in the acoustic treatment stage.

The staircase could be useful for additional bass trapping (depending on the size you could make it, and still fit through!), but needs to be behind you, as you need symmetry when mixing, ideally across the whole room, but as a last resort asymmetry can be behind you (John has done this in the past with odd shaped rooms).

I would seriously recommend, slowing the project down at least a month or so, to get the basics of HVAC etc. sorted out before constructing anything, you will need massive silencer boxes, and somewhere to fit them, you don't want to find out the best location for a silencer is behind a concrete wall. (Just in case you're wondering, HVAC is necessary not a luxury. You need to breath in an air tight room and extract humid air)

Dan

[Gregwor]

How do you plan to obtain isolation while including the stairs in your design?

Greg