Studio in Azeitão - Portugal

So what kind of solutions do I have?

Try entering potential wall construction materials here to see the transmission loss results: Gregwor & audiomutt’s MSM Transmission Loss Calculator Version 2.02 Greg

Thank you Gregwor. I need you help to use this. Can you help me? I don't find the bricks I have. I have this https://pedreirao.com.br/wp-content/uploads/2015/05/tijolo-ceramico-parede-construcao-obra-reforma-pedreiro-pedreirao.jpg I only have this. It's the standard wall in Portugal. Bricks like this and cement in both sides. This is a 11cm brick. My idea is now add a second leaf with rockwool and drywall to get the insulation that I want.

Simple solution: Go to the store, and buy one brick. Take it home. Weight it very carefully. Measure the face area very carefully. Divide the weight by the area. Now you have the surface density. - Stuart -

I need you help to use this. Can you help me?

The calculator allows you to enter your own custom surface density. So either find out the density of the material through product datasheets or do it the way Stuart described. From there, you should be good to go! Greg

I found the datasheet of a standard brick. https://www.preceram.pt/documentos/FT_CE_PRECERAM.pdf This is my first test: https://docs.google.com/spreadsheets/d/1nEcjo9pKn_F7uVexhLPPmss8ZM0ztO2nEMJ_xjGI-A8/edit#gid=1543869474 If I did it correctly, I think I need more insulation on the low end. Especially in the live room. I've a doubt: I've a first leaf made of brick. The second one is only two layers of gypsum. Where I put the rockwool? Sorry about my stupid questions :horse:

I've a doubt: I've a first leaf made of brick. The second one is only two layers of gypsum. Where I put the rockwool?

In between those two. The insulation goes in the gap between the outer leaf and inner leaf.

Sorry about my stupid questions

They are not stupid! It would only be stupid if you did NOT ask a question that you need answers to... :) - Stuart -

In between those two. The insulation goes in the gap between the outer leaf and inner leaf.

But this does not calculate the isolation, does it? This will depend on the material I use. it's very difficult to get the same value of the insulation of the bricks with the materials available in my area. The most common is gypsum board. Even with 4 gypsum board I can't get the same value. I've to do a market research to get the values of the insulation of gypsum board in stores near me. Green glue is a good thing to glue all the boards?

But this does not calculate the isolation, does it? This will depend on the material I use.

Stated above the dB results on the left column in your picture, is "Transmission Loss in dB with insulation (isothermally)" I believe the MSM formulas are based off of perfectly filled cavities using insulation with the correct gas flow resistivity to dampen resonant frequency of the wall system.

it's very difficult to get the same value of the insulation of the bricks with the materials available in my area.

I'm not sure what you mean by insulation. Do you mean isolation? Do you mean the same amount of surface density for your inner leaf as your brick outer leaf? Please clarify.

The most common is gypsum board. Even with 4 gypsum board I can't get the same value.

You don't NEED to have the same amount of surface density. I'd say as long as you have at least two layers of drywall, your outer to inner leaf surface density is enough to work. I know bricks density is crazy compared to drywall though. So, if you put in two layers of drywall for your inner leaf and the brick for you outer leaf, check how those results calculate. If they appear to achieve roughly what your isolation requirements are, then hooray.

I've to do a market research to get the values of the insulation of gypsum board in stores near me.

Again, I assume you mean surface density?

Green glue is a good thing to glue all the boards?

No. Even though there is the word "glue" in the name, it is far from glue. It's like sticky goop that never dries. You still need to use drywall screws in your drywall like normal. Greg

I believe the MSM formulas are based off of perfectly filled cavities using insulation with the correct gas flow resistivity to dampen resonant frequency of the wall system.

Ok, new calculations to learn!

I'm not sure what you mean by insulation. Do you mean isolation? Do you mean the same amount of surface density for your inner leaf as your brick outer leaf? Please clarify.

Again, I assume you mean surface density?

Yes and yes... I assume insulation and isolation has the same meaning. I googled it and understand the difference :wink:

You don't NEED to have the same amount of surface density. I'd say as long as you have at least two layers of drywall, your outer to inner leaf surface density is enough to work. I know bricks density is crazy compared to drywall though. So, if you put in two layers of drywall for your inner leaf and the brick for you outer leaf, check how those results calculate. If they appear to achieve roughly what your isolation requirements are, then hooray.

It appears to result. Only on the low end I don't get great results. But about 70 dB at 80Hz it's good especially for the control room.

It appears to result. Only on the low end I don't get great results. But about 70 dB at 80Hz it's good especially for the control room.

The MSM equations do not consider the limitations of mechanical transfer of the floor. 70 dB at 80Hz is basically unrealistic. Sure, if your walls were decoupled from everything and the room was floating or even on it's own slab, then maybe you could get 70dB of isolation at 80Hz, but for a normal home studio build, the laws of physics don't allow us to achieve such high isolation without going a step further than a basic room in a room construction. Having said that, if the calculator shows those numbers, chances are you are going to get great isolation provided you build with care. Greg

Thank you Greg! So just to clarify. My room within a room will only have 1 wall, the new drywall wall, decoupled from the brick wall with isolation in the gap between both. Is this? I need to understand this to design the sketchup model.

But about 70 dB at 80Hz it's good especially for the control room.

Why would you need 70 dB isolation at 80 Hz? :shock: That's rather extreme!!! Are you planning to have real guns and canons in there? Here's a graph of the isolation for a really good wall: Take a close look: at 80 Hz, it s getting maybe 38 dB of isolation, roughly. And that's a VERY good result. The overall isolation of that wall is around 70 dB, which is probably higher than the flanking limit for most home studios. Why do you need more than that?

My room within a room will only have 1 wall,

Not if you want it to isolate! It will have TWO walls: or rather, it will have a wall that is made up of two "leaves": the "outer-leaf" and the "inner-leaf". Like this:

the new drywall wall, decoupled from the brick wall with isolation in the gap between both. Is this?

Right. The brick wall is the outer-leaf of your isolation system, the drywall on the frame is the inner leaf. But you do need to make sure that your outer-leaf completely surrounds the studio, and that the inner leaf is a complete sealed shell as well. Two leaves as in the image above. Both are complete "shells", unbroken continuous mass around the studio (except for the doors, windows and HVAC, of course: not shown in the above diagram). - Stuart -

Take a close look: at 80 Hz, it s getting maybe 38 dB of isolation, roughly. And that's a VERY good result. The overall isolation of that wall is around 70 dB, which is probably higher than the flanking limit for most home studios.

Ok, I understand. 70dB is the overall. I think it's enough for me! Me playing drums is near 120dB!

Not if you want it to isolate! It will have TWO walls: or rather, it will have a wall that is made up of two "leaves": the "outer-leaf" and the "inner-leaf". Like this:

Understood! My walls will be built with a material call Viroc http://www.viroc.pt/homepage.aspx (similar to gypsum board but made with ciment and wood. It's more dense than the densest gypsum board that I found in the market) glued to gypsum board. Together they have a TS of 35.21. I've a new sketch from the control room. I think I'm going crazy with this RFZ!! But this is the best I can do to have a RFZ in a good proportion of the room. I know I will sit very close to the first reflections, but I have to close this part of the project to go forward and start to building soon. I had to angle the speakers to 20º to get a mixing point at 36% of the room without reflections. Doubts: the distance between speakers and the 40º angle.

Did anyone have chance to see my last post? I need to confirm if the design is correct to do the 3D design. I'm currently working on HVAC, electrical and doors. Also I'm working on the design of the live room. Duarte

I think I'm going crazy with this RFZ!! But this is the best I can do to have a RFZ in a good proportion of the room. I know I will sit very close to the first reflections, but I have to close this part of the project to go forward and start to building soon. I had to angle the speakers to 20º to get a mixing point at 36% of the room without reflections. Doubts: the distance between speakers and the 40º angle.

If you want less angle, I think a simple solution would be to just move your soffits closer to you. It will help fit deeper speakers anyway. Greg

I think a simple solution would be to just move your soffits closer to you.

Or move the speakers further apart: they do seem to be a bit close together.... 147cm isn't too bad, but it doesn't seem to fit the room width. What is the width of the room? Also, the "wings" on your soffits seem to be angled too much: I can see where you would get reflections from the opposite speaker, back to the mix position. One more thing: the soffit baffle itself is only 50cm wide: that's not very much, given all the space you have there. I would try to make the main baffle wider, and the wings smaller, with more space between the speakers, and better angles all around. - Stuart -

What is the width of the room?

310cm and 470cm length

One more thing: the soffit baffle itself is only 50cm wide: that's not very much, given all the space you have there. I would try to make the main baffle wider, and the wings smaller, with more space between the speakers, and better angles all around.

I tried to do that, but only works if I move mix position to close to 25% of the room and lost the empty space to put a analogue mixer. I need at least 100 cm to the mixer. My room is very very similar to this one: http://www.johnlsayers.com/phpBB2/viewtopic.php?f=1&t=21377&start=0 I think is mixing position is to close to 25%... But, of course, I'll try again :) I'm plan to build the studio this summer (1 year later than I had planned!)

I tried to do that, but only works if I move mix position to close to 25% of the room and lost the empty space to put a analogue mixer. I need at least 100 cm to the mixer.

Instead of moving YOU, move the entire front wall assembly towards you. Problem solved :thu: Greg

I tried to do that, but only works if I move mix position to close to 25% of the room and lost the empty space to put a analogue mixer. I need at least 100 cm to the mixer.

Why? Don't move the mix position: Just change the angles of the speakers!!! - Stuart -

Why? Don't move the mix position: Just change the angles of the speakers!!!

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

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... :oops:

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.