John Sayers' Recording Studio Design Forum Archive

Try it.

Greg

But, theoretically, if I change the angles of my speakers the ideal mix position moves... or not ?

Who says that it is idea?

The famous "equilateral triangle" looks nice on paper, and on internet web pages, and it works for most rooms and most speakers... which is why most manufacturers put that in their manuals. But that doesn't mean that it is optimal for all rooms and all speakers... or even optimal for most rooms and most speakers! It WORKS for them, but isn't necessary BEST for them.

Take a look at photos you see of high-end control rooms from all over the world, and you'll notice that not all of them have the speakers angled at exactly 30°, or set up exactly in an equilateral triangle...

As Greg said: Try it!

Get out your best speakers, set them up in a good room in your house, and see what happens if you put them in the "standard" equilateral triangle setup, with the speakers aiming at your eyes (NOT your ears!)... because that's what the "standard" equilateral triangle diagrams show, so set i up exactly like that... then do a second setup, with the speaker spread a bit further apart, and aimed at a point about 16" behind your head, without worrying about the angle... and tell us if that sounds better or not... Wider sound stage, clearer stereo imaging, more defined phantom center, better sweet spot...

- Stuart -

Wider sound stage, clearer stereo imaging, more defined phantom center, better sweet spot...

Actually my temporary setup was set up in this way. Sounds very nice and balanced. It's a room without treatment.
My problem is to get a mix position further way at but without reflections.... I must have made 100 different designs!

Try it.

I tried but the real space between me and the front wall is smaller...
Reducing the room size the mix position will be in a percentage closer to the ideal, make sence. But will not fit an analogue desk!

I'm working on a new design... I will not give up!!!

I tried but the real space between me and the front wall is smaller...

Why is that a problem?

But will not fit an analogue desk!

How big is your console? What console is it? (brand and model).

- Stuart -

Why is that a problem?

Because I want a big room...

How big is your console? What console is it? (brand and model).

I'm looking for a Burbank Audio Systems Custom Series 75. The 24 channels has 135cmx99cm.

This is my new design. I think this is it! I moved the front wall forward like Gregwor said, and it works!
Now I've a good RFZ, the analogue mixer will fits well and the room proportions are much better!
And that works with the standard 30º angle!
Now the room has 240x310x400 it gives a room propostion of 1:1.29:1.68.

Because I want a big room...

Then why did you just make it 20% smaller?

You still have not changed your speaker angles. You are still stuck at 30° toe-in, with 60° axis intercept. Until you change that, you aren't going to get a good layout for your room.

the analogue mixer will fits well

Not understanding you at all now! Before you had 177 cm from mix position to soffit center: now you only have 144cm! How is that better?

When I suggested that you should change your angles before, reducing that same distance to something like you have now, you said that would not work because it "lost the empty space to put a analogue mixer". Very confusing: when other people give you advice you say it can't be done, then you come up with a plan yourself that does exactly that, and it is fine!!!

the room proportions are much better!

Ummmm.... no. The room proportions have not changed. The room is still 4.7m long and 3.1m wide. And your head is now at the 50% point of the room.... Thus, this situation is far worse than it was before.

I moved the front wall forward like Gregwor said

No. You moved the front face of the SOFFIT, not the front wall. The wall is still exactly where it was before.

Now I've a good RFZ,

No you don't. You still have serious reflections from the opposite side wings back to the mix position. I don't even need to ray-trace to see that.

Have you done ray-tracing, to check the ACTUAL reflection paths?

And that works with the standard 30º angle!

Why are you stuck on that angle, when it is not optimal for ANY room, especially a long and narrow one like yours?

Now the room has 240x310x400

No, because you did NOT move the wall! You just moved the soffit.

Even assuming that you DID move the wall, if you did that you would be reducing the floor area from the original 14.6m2, which is already very small (way smaller than the recommended 20m2 according to specifications), to the even tinier size of just 12.4m2. So you would reduce the size of the room by 16%, just so you can keep the angle of 30°, which you don't even need to keep anyway.... That reduces the room volume from 35m3 down to just 29m3... when it should be at least 47m3, according to specs. So you would be shrinking your room from about 75% of the recommended volume to about 60% of the recommended volume for a control room...

I really don't understand why you do not want to take our advice. But I'll try again:

1) FORGET THE 30° ANGLE! It is not needed, not optimal, and is causing you to make bad decisions trying to chase it.

2) FORGET ROOM RATIOS! There is no need to chase a ghost! The ratio of your UNTREATED room isn't fantastic, but also isn't terrifying: it is only just outside the Bolt area, and nothing to worry about. With decent speaker soffits in the front and deep treatment in the back, you'll be fine.

3) Maximize room volume! Don't do anything that would shrink our room more: it is already small. Work hard to keep it that way. Maximizing your room interior volume is far more important that chasing after room ratios or speaker angles, that are NOT important.

4) Before you do anything else, you first need to draw the actual size of the room after the isolation is done. You have not show that yet. Right now, as far as I can tell, you are only showing the size of the outer leaf, then the treatment, but not the isolation plan. Isolation is going to take up a lot of space, and reduce the size of the final inner-leaf room. We don't yet know what the actual size of that final isolated room is going to be, and until we do, there's no point in setting out soffit walls, wings, speakers, and the mix position.

5) Do things in the right order: FIRST define your isolation, THEN once you have that in place, start working on the speaker locations, soffits, mix position, and LAST OF ALL the treatment. Designing the treatment is what you do at the end, once the basic geometry of the room is known. You can't really design the treatment much until you know where the mix position and speakers will be, and what the soffit angles will be. Those locations define where most of the treatment has to go...


- Stuart -

Stuart,
I'm new on this. I know nothing about studio design and construction. All I "know" I learned with you guys and in some books over the last year. I'm a musician and sound technician. I never studied architecture or acoustics. Only musical acoustics.
When I had the opportunity to have my own studio I decide not have a control room like the most I used to record that sounds like shit even with very good studio monitors.
I found this forum, read some posts and I understood the importance of the room design before building, so I want to learn and follow your advice.

This design was made with that advice. I said the space is not enough but I said I'd try. Gregwor said “I think a simple solution would be to just move your soffits closer to you”. And you guys insisted that I try! So I tried!
I did ray tracing and input the draw on the amroc ray tracing tool and not see any reflections on mix position. Please show me these reflections because I do not see them. I’m not chasing 30º angle. With this design when I do ray tracing this works for me. I tried with another angles and I got reflections. Maybe I do not know how to do ray tracing and how to use the amroc tool.
Please show me how I found the soffit angle, I do not understand yet. Maybe it's very easy but I don't understand...

So here my empty room with isolation and the new wall.
The room has 5,27x3,1.
12cm of insulation (orange) and 31 mm of drywall and viroc (15mm drywall and 16mm viroc -gray). The black line is the existing room. It’s fine? Can I move to the next step?

Please show me these reflections because I do not see them.

How big is that sphere representing your head?

Maybe I do not know how to do ray tracing and how to use the amroc tool.

Your ray tracing looks about right but I'd prefer to do it by hand and check any intersecting corners.

Please show me how I found the soffit angle, I do not understand yet. Maybe it's very easy but I don't understand...

Trial and error. Adjust the soffit angle and do the ray trace again. After even the second attempt, you'll see how the wall angles are affecting things and the angle adjustment will become easier to determine.

So here my empty room with isolation and the new wall.
The room has 5,27x3,1.
12cm of insulation (orange) and 31 mm of drywall and viroc (15mm drywall and 16mm viroc -gray). The black line is the existing room.

Where is the gap between your outer wall and your inner leaf framing? Why don't you have two doors? Why don't you have two windows? Where are your HVAC duct work and silencer boxes going? This is all part of your isolation design. From there, like Stuart said, you place yourself, your speakers/soffit walls then your treatment.

It’s fine? Can I move to the next step?

As I just pointed out, you're on the right track. You're working hard and you're asking the right questions. Just address the points I made above and you're good to go. Stuart pointed out that your room ratio is fine. If you need to shorten your room to fit silencer boxes, that'd be fine. Put your head at the right spot in the room and move your soffit walls accordingly.

Greg

Thank you Gregwor for your kind words! This is all new to me and I need all help to continue on the right track.

How big is that sphere representing your head?

40cm diameter. I really would like to see this reflections to understand what I'm doing wrong.

Your ray tracing looks about right but I'd prefer to do it by hand and check any intersecting corners.

Usually I'm do by hand and do a double check on this tool.

Trial and error. Adjust the soffit angle and do the ray trace again. After even the second attempt, you'll see how the wall angles are affecting things and the angle adjustment will become easier to determine.

So the best way to do it it's put my head where I want (something near 38% of the room) and guaranty no reflections in a 2ft sphere?

If you need to shorten your room to fit silencer boxes,

Maybe I don't' need. I have a garage in the next room with plenty of space to the silencer boxes.

Where is the gap between your outer wall and your inner leaf framing? Why don't you have two doors? Why don't you have two windows? Where are your HVAC duct work and silencer boxes going? This is all part of your isolation design. From there, like Stuart said, you place yourself, your speakers/soffit walls then your treatment.

I'll design again with all of it.

So the best way to do it it's put my head where I want (something near 38% of the room) and guaranty no reflections in a 2ft sphere

Correct.

Maybe I don't' need. I have a garage in the next room with plenty of space to the silencer boxes.

You could house your OUTER leaf silencer boxes there. But what about your INNER leaf silencer boxes?

I'll design again with all of it.

That's the spirit!

Greg

You could house your OUTER leaf silencer boxes there. But what about your INNER leaf silencer boxes?

I'm thinking put in the ceiling like you did with your friend Darren.
I'm 20cm space. Would be enough?
How I calculate the size of the silencer boxes?

I'm drawing the control room in 3D.
I'm using steel studs with 90mm. It's the most common in my area. Is it enough?
My new wall will have 90mm insulation, 15mm drywall glued to 16mm Viroc. A gap of about 5cm between outer wall and inner leaf framing.
TL 39.95 in outer leaf and TL 35.32 on inner wall.
What do you think?

How I calculate the size of the silencer boxes?

Figure out the cross sectional area you need inside of your silencer boxes. Then for your joist cavities, you can use the diagram I posted near the bottom of this page:

http://www.johnlsayers.com/phpBB2/viewt ... =1&t=21752

I'm using steel studs with 90mm. It's the most common in my area. Is it enough?
My new wall will have 90mm insulation, 15mm drywall glued to 16mm Viroc. A gap of about 5cm between outer wall and inner leaf framing.

Try to fill all gaps/voids with insulation. Leave no "air".

Greg

Hi guys,
Here's my room in 3D.
I done the raytracing and the ceiling raytracing.
My inner room has 3,02x5,27x2,4, about 38m3 and 16m2.
Mixposition is at 34% of the room. 1,80m of the front wall and 1,50m of the soffit. A analog mix will fit.
Because some existing walls have a frame close to the ceiling the insulation cavity in some places will be 15 cm.
What is the best insulation? Rockwool? With what density?

Now I'm study where my HVAC could work.
And how to construct the soffits.

Because some existing walls have a frame close to the ceiling the insulation cavity in some places will be 15 cm.
What is the best insulation? Rockwool? With what density?

Fibreglass in kg/m^3
High Freq = around 40 (others say 60-80)
Mid Freq = around 35
Low Freq = 20-25

Mineral Wool in kg/m^3
High Freq = around 65 (others say 90-120)
Mid Freq = around 55
Low Freq = around 30 (others say 40-45)

So, you want to shoot for insulation that will perform well at low frequencies as the resonant frequency of your wall system will be very low.

I notice your inner leaf wall corners aren't connected to one another. They need to be. Good work so far!

Greg

I notice your inner leaf wall corners aren't connected to one another. They need to be

I know, it's only in sketchup.

So, you want to shoot for insulation that will perform well at low frequencies as the resonant frequency of your wall system will be very low.

How I know the resonant frequency of my wall? With your MSM TL Calculator?

Fibreglass in kg/m^3
High Freq = around 40 (others say 60-80)
Mid Freq = around 35
Low Freq = 20-25

Mineral Wool in kg/m^3
High Freq = around 65 (others say 90-120)
Mid Freq = around 55
Low Freq = around 30 (others say 40-45)

It's possible to use rock wool? In Portugal it's more common selling rock wool instead of fibreglass or mineral wool. And it's more cheaper.

A doubt:
The walls in red will need more isolation, because the existing walls are thin and turned inside the house. The walls in blue are underground, thick and outside walls.
My inner room needs the exact same density in all 4 walls? I will use drywall + viroc, but in the blue walls can I use only drywall?
It would be a saving of 20m2 of viroc.