Studio in Azeitão - Portugal

[Soundman2020]

But now I have a decent sound level meter to measure how much I really need to attenuate!

Excellent!

Should I make the noise tests inside the room using pink noise?

Pink noise is used for calibrating the speaker and REW, for doing measurements within the room, but it is not used for testing isolation: It is too similar to background noise, so it's no use for testing outside, where it sounds more or less the same as ambient sound in the neighborhood. Test only with real music. Set up a full-range speaker inside the room, and play loud, bass-heavy music in here, at around 110 dB if you can (wear ear protection!!!). Measure the level in the room, with your meter set to "C" weighting and "Slow" response, about 3 feet away from the front of the speaker. The go out of the room and measure in many places in and around the rest of the building, at various distances, including at your property line. Make notes of the level at each location. The go back inside, turn off the sound system, and measure again at all those exact same locations, with just the ambient noise. Also repeat the "ambient" measurement at the quietest possible time of day, probably something like 3 AM on a Sunday morning, or some such, so you have a reading of the lowest typical background level, as well as the normal day-time background level.

I will also measure a full band rehearsal.

Excellent! If you can do that, then it's a great supplement to the above test. Get the band to play the same song over and over, playing at the same level each time, while you do your measurements. One again, measure inside the room first, then in the same points you did before outside the room, when you just had the speaker.

Sorry I'm very slow with my project ...

Slow is MUCH better than fast! Don't rush! Take your time at every stage, to make sure you are getting it right. Rome wasn't built in a day, and your studio can't be designed in a day either! It takes months, typically.

- Stuart -

[Duarte_Vader]

Slow is MUCH better than fast! Don't rush! Take your time at every stage, to make sure you are getting it right. Rome wasn't built in a day, and your studio can't be designed in a day either! It takes months, typically.

Cool! I was thinking I was the slowest guy on the forum! It's a studio in my home for (I hope) the rest of my life, so I have time to do it well|

Stuart did you have the chance to see my last room design?

[Duarte_Vader]

...It works great for everyone who has had their ears surgically transplanted onto their eyeballs, but for the rest of us, it's clearly not the best.

I'm very attached to the equilateral triangle. I never thought in another way to do this.
I think I understood all the points you talked about and there it is a new version of RFZ room.
I angled the speakers to 25º, so now I have the mix position at 36% of the room, 60cm ahead of spot point of the triangle.
If I go more closer to the point I start having reflections.

Tomorrow I will measure the room!

RFZ_v3.JPG

.

RFZ v3_RT.JPG

Hi!
Someone had the chance to saw my last design?

[Gregwor]

I don't like the fact that you will hear a reflection if you lean back in your chair. Can you move the side wall out more so that the troublesome reflection moves further behind you?

Also, have you attempted to address your ceiling angles to ensure RFZ as well yet?

Greg

[Duarte_Vader]

Hi again guys!

I have an architect help me with the design and 3D model but I need your help with the insulation.

Pink noise is used for calibrating the speaker and REW, for doing measurements within the room, but it is not used for testing isolation: It is too similar to background noise, so it's no use for testing outside, where it sounds more or less the same as ambient sound in the neighborhood. Test only with real music. Set up a full-range speaker inside the room, and play loud, bass-heavy music in here, at around 110 dB if you can (wear ear protection!!!). Measure the level in the room, with your meter set to "C" weighting and "Slow" response, about 3 feet away from the front of the speaker. The go out of the room and measure in many places in and around the rest of the building, at various distances, including at your property line. Make notes of the level at each location. The go back inside, turn off the sound system, and measure again at all those exact same locations, with just the ambient noise. Also repeat the "ambient" measurement at the quietest possible time of day, probably something like 3 AM on a Sunday morning, or some such, so you have a reading of the lowest typical background level, as well as the normal day-time background level.

I did this test and the ambient noise outside is 47 dBC during the night and 50 dBC during the day. It’s a quiet zone!
I did several tests in both rooms with a PA system at 110 dBC and I could feel vibrations upstairs mostly caused by bass drum and snare drum of the song. The bass is also felt but with less intensity. How can I handle with these vibrations?
Outside the maximum was 70 dBC but a car passing way the street does more noise.
A band playing is around 120 dBC. But a louder band could be more. I measured a band but not in this room.

So I think if I could absorb something between 30 and 40 dBC in Live Room a band playing inside real loud could not be listen outside. And I need a door or two to insulate 80 dBC! It’s possible?
The control room is almost the same but, of course, I don’t need too much insulation. Something between 20 and 30 dBC could be enough.

My biggest concern is the walls facing the inside of the house. These walls insulate about 30 dBC. I need more 30 or 40.
What could be the correct insulation?

The rest of the walls are under the ground.

[Gregwor]

I have an architect help me with the design and 3D model but I need your help with the insulation.

Can you post some pictures of the design so far?

How can I handle with these vibrations?

A fully decoupled inner leaf - also referred to as a room in a room.

The bottom end may always be felt through your concrete slab. One solution to the structure borne vibrations would be building a drum riser in which the riser itself "floats" on insulation. You can also build little risers for the bass guitar.

Outside the maximum was 70 dBC but a car passing way the street does more noise.

What does your district bylaw state is the legal limit at your property line though?

So I think if I could absorb something between 30 and 40 dBC in Live Room a band playing inside real loud could not be listen outside.

So 120dB with 40dB of isolation will put you at 80dB.

And I need a door or two to insulate 80 dBC! It’s possible?

80dB of isolation is probably near impossible in a residential non-purpose build building. No matter what though, if you are trying to attenuate a live band playing down to legal volumes, you WILL need a room in a room where each leaf has it's own acoustic door.

The control room is almost the same but, of course, I don’t need too much insulation. Something between 20 and 30 dBC could be enough.

If that's what you feel, then now you know you don't need to be as extreme with your construction methods for the control room.

My biggest concern is the walls facing the inside of the house.

The thing about acoustics and isolation is that your studio room is like a fish bowl. All the walls (and ceiling) need to be built out of the same material and have the same surface density. That includes the doors and the windows. You can't just build one wall super crazy and expect the room to have total isolation. The sound will penetrate the other walls and pollute the surrounding areas.

These walls insulate about 30 dBC. I need more 30 or 40.

So you want it to isolate between 60 and 70dB total? If so, you need to design and build very accurately because to achieve even 60dB of isolation is a task! Totally possible though.

What could be the correct insulation?

For between your leaves?

The rest of the walls are under the ground.

So some of your rooms are not in the basement? Some are? I'm really needing to see some drawings to understand where rooms are and such.

Greg

[Soundman2020]

Something between 20 and 30 dBC could be enough

A normal house wall provides about 30 dB of isolation, or maybe 35 if you are lucky. So you are saying that your control room needs LESS isolation that a normal wall?

You should probably do some experiments with music playing at different levels, to better understand what these numbers mean, and get a better estimate of how much isolation you need. If you are playing music at 90 dB in the control room, and have only 20 dB of isolation, then you will have 70 dB outside the room. That is loud. People standing outside the room would need to raise their voices a bit to have a conversation.

- Stuart -

[Duarte_Vader]

So 120dB with 40dB of isolation will put you at 80dB.

A normal house wall provides about 30 dB of isolation, or maybe 35 if you are lucky. So you are saying that your control room needs LESS isolation that a normal wall?

Sorry I did not express myself well... I need 40 dB extra to get to the insulation I want! I have walls, but they don't have enough insulation. I need to improve these walls.

So you want it to isolate between 60 and 70dB total? If so, you need to design and build very accurately because to achieve even 60dB of isolation is a task! Totally possible though.

Yes!!!
I’m thinking in room within a room with 40 dB insulation walls fully decoupled from the existing brick walls. These new 40 dB walls more 30 dB from brick walls I get 70 dB. It is correct?

What does your district bylaw state is the legal limit at your property line though?

I think it's 65 dbA. But it won't be a problem. The nearest neighbour is more than 20m from my property.

Can you post some pictures of the design so far?

I don't have a new picture. He's drawing me my RFZ control room. I cannot draw it alone. Once I have a new image, I'll send it to you.

80dB of isolation is probably near impossible in a residential non-purpose build building. No matter what though, if you are trying to attenuate a live band playing down to legal volumes, you WILL need a room in a room where each leaf has it's own acoustic door.

I can do that. I have enough space to have two doors.

[Soundman2020]

These new 40 dB walls more 30 dB from brick walls I get 70 dB. It is correct?

No. Unfortunately, it isn't that simple. There are many factors that affect how well a two-leaf wall isolates, mostly related to different forms of resonance. So you can't just add the the isolation produced by each leaf to get the total. It would be nice if you could do that, but that's not the way it works.

I think it's 65 dbA. But it won't be a problem.

That is unusually high. Most residential codes these days specify something like 50 dBC in daytime and 40 dBA at night, or something in that region. 65 would be unusual, unless it is an industrial area.

[Duarte_Vader]

No. Unfortunately, it isn't that simple. There are many factors that affect how well a two-leaf wall isolates, mostly related to different forms of resonance. So you can't just add the the isolation produced by each leaf to get the total. It would be nice if you could do that, but that's not the way it works

So what kind of solutions do I have?

e.g.:
Existent 13cm brick wall --> 2 layers of rockwool --> 2 drywall layers with green glue. Could be enough?

wall.JPG

That is unusually high. Most residential codes these days specify something like 50 dBC in daytime and 40 dBA at night, or something in that region. 65 would be unusual, unless it is an industrial area.

I checked and is 55 dBA in daytime and 45 dBA at night. During the day is about 37 dBA outside. But it won't be a big problem. I live in countryside, I only have 2 houses near me but more than 20m away. My biggest concern is inside the house with my family.

[Gregwor]

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

[Duarte_Vader]

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/upl ... reirao.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.

[Soundman2020]

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 -

[Gregwor]

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

[Duarte_Vader]

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/ ... 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