John Sayers' Recording Studio Design Forum Archive

Hi I am interested in making treatments like these:

http://www.johnlsayers.com/HR/index1.htm

I am a bit confused about the 1st paragraph where it says "The variables are the depth from the wall, the width of the slats and the width of the gaps between the slats. "

Ok so if those are variables, how do I go about defining these measurements for my own studio build? Also is it really better to use rigid fiberglass or can I use the lighter fluffy stuff instead (I don't get rigid fiberglass around these parts but I believe the light yellow fluffy is superior for absorption to rigid)

cheers

I am a bit confused about the 1st paragraph where it says "The variables are the depth from the wall, the width of the slats and the width of the gaps between the slats. " ... how do I go about defining these measurements for my own studio build?

First, why did you choose that particular device? Not a trick question, but it's the key to understanding how to treat your room. You must have chosen that device because you think you will need it in your room, to deal with a certain problem: What problem? So you would tune the device to the correct frequency or range of frequencies for the problems you are having in YOUR room.

Also is it really better to use rigid fiberglass or can I use the lighter fluffy stuff instead (I don't get rigid fiberglass around these parts but I believe the light yellow fluffy is superior for absorption to rigid)

"superior" in what way? Also not a trick question. Each type of insulation is better for some applications, worse for others. For example, very dense, heavy mineral wool insulation is lousy for bass trapping, but good for dealing with high frequencies. Light fluffy fiberglass insulation is much better for low frequency absorption, not so good for extreme highs. etc. It all has to do with a parameter called "gas flow resistivity", which is a measure of how well air can move through the isolation.

So it's not a matter that "soft is better than rigid" or "heavy is better than light", but rather to look at the application: what do you want the insinuation to do? Then choose the best one for the job.

Which gets back to the device you have chosen: If you want to use it as a bass trap, then go with a lower density insulation, something around 20 to 25 kg/m3 if it is fiberglass or 40 to 45 kg/m3 if it is mineral wool. If you want it to deal general in the mid range, but not so much for the low end, then around 35 kg/m3 if it is fiberglass or 55 kg/m3 if it is mineral wool. And if you just want it for the high end, then likely 40 kg/m3 if it is fiberglass or 65 kg/m3 if it is mineral wool is what you'd need.

- Stuart -

Soundman2020 wrote:First, why did you choose that particular device? Not a trick question, but it's the key to understanding how to treat your room.

Hi Stuart. The reason why I want to use the device is to tame the low mids in my live room/mixing room. Are you saying I should first test the room and see if it is necessary to use them? I was under the impression that all rectangular live rooms/control rooms would need low-mid treatment as well as low-end treatment so I was going to include these as part of my overall treatments in my room. In the past I have always just used thick layers of fluffy fiberglass which provide excellent absorption but they leave your room dead so I wanted treatments that wouldn't kill the highs completely this time round and I like that these units kind of diffuse sound as well as absorb..

I noticed from your other post, that your room is large: around 60m2 floor space. That's at the upper limit of rooms that are suitable for "critical listening", but still within the range. Your room can be fantastic, but it's going to need some careful design and treatment. Large rooms have different acoustic needs from small rooms. I would suggest that you take some time to study control room acoustics, and to design the interior layout, geometry, treatment, and tuning of your room to be the best it can be. It's not going to be as easy as simply putting up some slot walls on the sides of your room. You have modal support down to 14 Hz, and your Schroeder frequency is 77 Hz, with simple treatment, so your room is acting almost like an acoustically large room. Not quite, but getting close. It certainly is not a small room: all of your primary axial modes are below 60 Hz! That's unusual in a home studio or project studio. This can be more like a high-end professional studio, with dimensions like that. But it's going to need careful design.

- Stuart -

Soundman2020 wrote:I noticed from your other post, that your room is large: around 60m2 floor space. That's at the upper limit of rooms that are suitable for "critical listening", but still within the range. Your room can be fantastic, but it's going to need some careful design and treatment. Large rooms have different acoustic needs from small rooms. I would suggest that you take some time to study control room acoustics, and to design the interior layout, geometry, treatment, and tuning of your room to be the best it can be. It's not going to be as easy as simply putting up some slot walls on the sides of your room. You have modal support down to 14 Hz, and your Schroeder frequency is 77 Hz, with simple treatment, so your room is acting almost like an acoustically large room. Not quite, but getting close. It certainly is not a small room: all of your primary axial modes are below 60 Hz! That's unusual in a home studio or project studio. This can be more like a high-end professional studio, with dimensions like that. But it's going to need careful design.

- Stuart -

Thanks Stuart. That's what I am after. Just out of curiosity, how much would it cost me to get a basic design for this space. Just for someone to tell me what I need to do for the best possible results?

Thanks Stuart. That's what I am after. Just out of curiosity, how much would it cost me to get a basic design for this space. Just for someone to tell me what I need to do for the best possible results?

I did PM you about that. Not sure if you saw it?


- Stuart -

Soundman2020 wrote:

Thanks Stuart. That's what I am after. Just out of curiosity, how much would it cost me to get a basic design for this space. Just for someone to tell me what I need to do for the best possible results?

I did PM you about that. Not sure if you saw it?


- Stuart -

Yes I did. I am going to consider some consultation for my studio for sure and you really seem to know your stuff.

Yes, a professional consultation can help you in a better way.