Basement Recording Studio- l'hôtel particulier house, France

[lukeclark]

Hello! This is my first post. A day can easily disappear reading through this immense and very helpful resource! I am going to try and follow the rules and to provide information as concisely and informatively as I can.

Location: In the region of Mayenne, France
Phase: Currently in the costing / design phase of a residential recording studio
Budget: 50k for construction (including communal areas)
Current Plans: Image below

Building:
> The basement area of a l'hôtel particulier style house built in the 1900
> A brick vaulted ceiling throughout with mud flooring
> Approximately 1,700 sq ft
> Ceiling height of 7.5-8.2 ft (the possibility to dig down at least another 3ft)
> Wall Exterior width is 2.1ft. Wall Interior width is 1.6ft except ‘Vocal booth /
Iso Room’ which is also 2.1ft.

Layout and usage:
> Control Room: 17.9 x 14.6ft
> Live room: 18 x 13.4ft with an alcove area 11.6 x 5.5ft
> Vocal/Iso Booth: 10.3 x 9.7ft
> Communal Area/Bedroom: The communal area will comprise of a kitchen, bathroom and table. Dimensions of these areas are on the plan below
> Entry: There are two entries to the basement, one from upstairs, and one from Basement level. The Basement entrance will be the main entrance to the studio.
> Timescale: As soon as is possible (preferably by the end of 2016).
> Studio Usage: Recording bands of any genre with a focus on acoustic folk and alternative rock

Points to note:
> The layout is not set in stone (well, actually it is a type of stone!), but how these areas are used could change according to any input.
> Following advice from a Chartered Surveyor, I am considering moving the heating (and a noisy boiler) from the bedroom to the communal area
> Due to the thickness and density of these walls, I expect that the main isolation that needs to be addressed will be the windows, doors and structural borne sound coming through the ceiling and possible airborne sound coming from the studio to the 1st floor of the house.
> As part of the design below I would be adding a large window and a door from the control room to the live room to see bands performing and for easy access.
> I may add an additional smaller vocal/iso booth in the live room
> The control room is fairly large but I was hoping for enough space to accommodate a band to listen to what they have created without being cramped. Also, I may do some DI recording in the control room
> I am keen to keep some of the charm of the old cellar and a feeling of space and natural light.

Help needed
I have researched a fair amount about acoustics and how they work BUT it really is a science and I’m not sure if I have the time or ability to really get my head around it all (as much as I enjoy researching it!).
I have had some conflicting advice regarding angled walls vs straight walls. From the research I have undertaken, it seems that angled walls would be preferable (certainly within the control room).
I have also had some conflicting advice regarding the possibility of keeping some of the walls exposed within the live room

Questions

If isolation of the walls is not necessary (due to them being so thick), what is absolutely necessary for diffusion and absorption?

Is this design too boxy? Do I need to create angled walls? And, if so, how do I go about designing this whilst maintaining as much space as possible? For example, is it possible to build storage into these angled areas?

Does every wall need to be covered in soft furnishing? Or, is it ok to leave some of the walls exposed in the Live Room

Is it wiser to have a flat or angled ceiling? Would keeping the shape of the vaulted brick ceiling play havoc with reverberation throughout the space?

Thanking you in advance!

[Soundman2020]

Hi Luke, and welcome to to the forum!

A day can easily disappear reading through this immense and very helpful resource!

Very true! Or even longer than a day... it's been around 8 years for me, so far...

> The basement area of a l'hôtel particulier style house built in the 1900
> A brick vaulted ceiling throughout with mud flooring
> Approximately 1,700 sq ft
> Ceiling height of 7.5-8.2 ft (the possibility to dig down at least another 3ft)
> Wall Exterior width is 2.1ft. Wall Interior width is 1.6ft except ‘Vocal booth /
Iso Room’ which is also 2.1ft.

That sounds like an excellent location. What are the walls made of? 2 feet thick is REALLY thick, so I imagine you should get good isolation from that already. 1700 ft2 is a really nice, large space.

> Timescale: As soon as is possible (preferably by the end of 2016).

That should be possible.

I have had some conflicting advice regarding angled walls vs straight walls. From the research I have undertaken, it seems that angled walls would be preferable (certainly within the control room).

That depends on what design philosophy you decide to use for the CR. If you decide to go with an RFZ-style room (highly recommended) then yes, parts of the walls would be angled to produce that acoustic. The same applies to NER and CID design concepts. But that does not mean that you have to change the angle of existing walls: You can simple build the angled parts that will be needed as part of the new inner-leaf of your studio.

On the other hand, if you prefer to do a plain rectangular room, then you don't need to angle anything, but you do lose the benefit of the RFZ concept.

The speakers can be part of that decision. When I design a studio, the first thing I consider is the speakers that will be used in the room, as sometimes the characteristics of the speakers can affect how the room should be designed. Most speakers can be soffit mounted, for example, but some cannot. The dispersion angle, size, power and orientation of the speakers are all issues that should be taken into account. There are other factors too.

So it's not just a simple matter of "always build rectangular" or "always angle your walls". There are reasons for doing each.

I have also had some conflicting advice regarding the possibility of keeping some of the walls exposed within the live room

Here too that depends... it depends on how much isolation you will be getting from your existing structure, and how much isolation you need. If the walls that you already have are providing enough isolation as they are (and I suspect the might, as they are very thick), then you probably could keep one or more walls exposed to the room. But if you are not getting enough isolation, then you would need to build a complete "room within a room" to provide the additional isolation, and that would mean covering up your existing walls.

If isolation of the walls is not necessary (due to them being so thick), what is absolutely necessary for diffusion and absorption?

In the control room, there is a series of treatment items that you will need in order to get the room to be acceptable as a control room. The ITU document BS.1116-2 lays out the specifications that a control room should meet in order for it to be considered as a "critical listening room", and there are fairly common ways of doing the initial layout and treatment that will get you on the path to meeting those specs. Your control room is acoustically small, so it will need extensive bass trapping, and if you do not use an RFZ design then you will also need thick absorption on all of the first reflection points and between the speakers and the front wall. You will also need thick absorption and perhaps diffusion on the rear wall. Your room is large enough that you cold use diffusion there: many rooms are too small for that.

The initial treatment is fairly standard, but after that is done the normal procedure is to measure the room response using acoustic testing software (such as REW, which is free), and see what still needs to be done based on the results, and install new treatment to do that. Then repeat that process as much as needed until the response is good.

Do I need to create angled walls? And, if so, how do I go about designing this whilst maintaining as much space as possible? For example, is it possible to build storage into these angled areas?

I often use those areas for the HVAC silencers. If you do the angled sections correctly, they won't take up much space, and will be about the right size to fit in a typical silencer box.

Does every wall need to be covered in soft furnishing?

Definitely not! That would make the room sound dull, lifeless, "honky" or "boomy": The treatment in any room should be balanced carefully to provide the desired acoustic response. You need to put in just enough absorption and diffusion to do that, and it must be tuned to the correct frequency ranges.

Is it wiser to have a flat or angled ceiling?

For the live room, either is possible. Some treatment will be needed, of course, so it doesn't really matter.

For the control room, the ceiling needs to be symmetrical: the left half must be the mirror image of the right half. And it needs to be neutral, acoustically. There are several ways of accomplished that, depending on the initial acoustic response of the room, and the design concept.


- Stuart -