John Sayers' Recording Studio Design Forum

I tried to locate the JohnH thread without success Glenn.

Could you be kind and link the thread please?

Never mind, I found it Glenn. Thank you!

Have a question Glenn.

Q1) 3/4 inch is about 20 mm thick plywood you have on your example. It seems to me that the sound cloud will be heavy
using plywood if you add the MDF (even after it has been routed). Another potential weight problem is that I have to make boxes
for the lights made out of MDF which will also add weight.


Is there any other materials that could be used in order to make the cloud lighter?

Q2) The routed parts on your cloud example, can you tune the cloud by routing in order to optimize the rooms sonic characteristics?

Q3) How big should the cloud be to obtain the best possible result?

Q4) In your example there is a part of the cloud that is only plywood and no absorber (3 inches),
can you exclude that? Is it not reflective???

Q4) (This is more of a request) Can you provide some other Sketchup file of a cloud that I could learn from that
might be closer in line with what we are facing with my project?

Q5) My cloud would be 160 mm=6.2992126 inches thick. Would the low height
of my room (2.2 Meters after drywall is in place) present any acoustical problems Glenn

Q6) I made a sketch of the absorbers on the corners of the saws. Is it OK Glenn?

This post (see below) answers some of the questions I asked.
Still need assistance with the rest Glenn.
http://www.johnlsayers.com/phpBB2/viewtopic.php?f=3&t=15553&p=109691&hilit=cloud#p109691
viewtopic.php?f=3&t=9063&p=63188&hilit=cloud#p63188

An update; We have started work on the electrical aspects of this project, I will post
pics in the near future.

Sincerely,

Useg Diaz-Granados

Here is a model of the saws, broadband absorbers and the bass traps.

The broadband absorbers are 80mm thick while the bass traps are 160 (insulation+100mm empty space)mm thick.

Q1) Anything you think could be improved Glenn?

Q2) The wood for the frame of the broadband absorber (not the saws) I am thinking of making is 118 mm (thickness), the insulation is 80 mm.

What are the sound treatment advantages/disadvantages of making a frame that is 118 mm to house the 80 mm insulation,
placing a properly caulked 6mm MDF plate behind the insulation and then leaving the remaining space empty Glenn?

I am thinking of leaving a 65mm space that goes between the saw and the broad band absorber and make similar absorbers to the one you posted
that neutralizes the reflective corners of the saws.


Sincerely,

Useg Diaz-Granados

assuming cloth behind the slats, the air gap between the cloth and the insulation will be fine, the rigid insulation inside will dampen the cavity resonances.

_________________
Glenn

Thank you Glenn.

Q1) Could you be kind and answer the questions I asked that have to do with the sound cloud, the broadband absorber thickness/basstraps and
the wood frame Glenn?

Q2) Is the information on the links below accurate or is it outdated pertaining to
the open compared to the closed back bass trap and broadband absorbersGlenn?

http://www.johnlsayers.com/phpBB2/viewtopic.php?f=3&t=2423&p=17890&hilit=basstrap#p17890
http://www.johnlsayers.com/phpBB2/viewtopic.php?f=3&t=13226&p=91697&hilit=basstrap#p91697

My understanding is (from the information I've obtained in this forum) that you can tune the bass trap
in order to enhance lower frequency absorption by using space and a sealed/caulked back. Do you seal the back twice (when the insulation ends and after the space)?
Please correct me Glenn if I happened to miss-interpreted this important piece of information.



Sincerely,

Useg Diaz-Granados

Something went wrong when we installed the star led lights due to what I presume to be a defect in the product.

The lights transformer blew right in front of my eyes; watching this made me made me wonder why human beings would be so sadistic;
and decide to use electric current in order to execute someone in the name of a sovereign state in order to enforce the Law
......

(It is GREAT being in SWEDEN; no Death Row here, honorable members of this forum; it is also illegal for a
parent to hit her or his child; I don't know why but I just felt compelled to share that with Y'all LOL)

......
Anyway, I sent the lights back to the manufacturer so we can get new ones quickly.

In order to be able to move forward with the project; I would need the questions that I asked answered.

Since I am getting impatient ; I will make the frame for the broad band absorbers after celebrating midsummer, sort of like your thanksgiving Glenn although
I don't think the Swedes would eat lunch with Indians after stealing their land; after all they stayed neutral during WW2;
and made a hefty penny by selling steel to the Germans during that time-period .

I can not put up the drywall until the star led lights are up (don't you hate it when things get in the way of progress?).

I still need to know if the closed back+caulk or the open back option is the best way to pursue the assembling of the broad band absorbers and the bass traps.
......

Sincerely,

Useg Diaz-Granados

the slat air cavities need to be sealed to work effectively. the panel traps you show in one of the links can be tuned by putting the panel on a soft rubber edge and adjusting the tension - but - it's not necessarily easy to do, so start with broadband. on the broadband absorbers - the cloth cover rigid insulation, no need to seal them but leaving an air gap behind them will help increase the absorption.

_________________
Glenn

Thanks Glenn .

I will follow your recommendations.

Q) What about the Bass Traps?

Don't they need to be sealed/caulked Glenn?


Sincerely,

Useg Diaz-Granados

if they are membrane (panel) absorbers - they need to be sealed - the air cavity is part of the equation, if they are just deep absorbers, no.

_________________
Glenn

Thank you!

I have to use the search function and learn more about the difference in between a panel absorber
bass trap and a deep bass trap.

Here are some links that others here might find useful; due to my lack of understanding/knowledge concerning this
subject matter I can not guarantee the accuracy of this content.

http://www.johnlsayers.com/phpBB2/viewtopic.php?f=1&t=345&hilit=membrane+absorber
http://www.johnlsayers.com/phpBB2/viewtopic.php?f=3&t=1105&hilit=membrane+absorber
http://www.johnlsayers.com/phpBB2/viewtopic.php?f=1&t=1967&hilit=membrane+absorber
http://www.johnlsayers.com/phpBB2/viewtopic.php?f=3&t=3762&hilit=membrane+absorber
http://www.johnlsayers.com/phpBB2/viewtopic.php?f=3&t=6446&hilit=membrane+absorber

I found the last thread amusing......


Once again, my assertion after reading the post is that Eric Desart is the man!


Sincerely,

Useg Diaz-Granados

Eric is truly the man.

_________________
Glenn

After reading a little I believe that the most pragmatic approach to achieving my main objective
with the mix room is to go with the deep absorption bass traps and broad band absorbers.

If you believe this to be the least efficient way of sound treating the room please let me know Glenn.

If everything goes according to plan I will start assembling the broad band absorbers (not the saws) tomorrow.

Q) I wonder how problematic this design for my bass traps might be Glenn.

My thought process is that I need some weight in order to keep the bass traps stable since they are 2330 mm high.

I have decided to make the traps 240 mm thick.

There is some left overs from the door project which I presume will keep the bass traps stable (66 mm thick composite wood).
There will be some reflections since wood is a reflective surface; I wanna know what you think Glenn?

By the way, the back of the bass traps is not suppose to be made out of a solid material (it will be stapled cloth and sound treatment insulation).

Sincerely,

Useg Diaz-Granados

you could make smaller bass traps (ala BBC 1992-11) and stack them. either way, you'll want the bass traps as close to your corners as possible.

_________________
Glenn

As always, thank you Glenn!

I am feeling adventurous enough to try the 2330 mm tall traps with the composite wood (around 5 kg weight for each trap and 310 mm wide)
made out of MDF which is a heavy material. Not being a builder, I presume that the bass traps will stand sturdy like a abnormally large book shelf.

The bass traps I plan to make would not be the BBC version since those traps have a sealed back and, as I understand it, should be placed in direct proximity of a wall.

Q) Am I wrong in my presumption about the BBC traps Glenn, are there any disadvantages to making the traps with and "open" back and front
that you are aware of?

A quick update; I started on the broad band frame and up when routing the wood

I got better (although NOT perfect) on my second set. I checked the second piece out and it looks good for the tall people who will actually be able to see it
(will be on the top part of the frame).

I will nevertheless use the bad piece since it will not be seen (place them on the bottom of the frame closest to the wall) once it goes on the wall.
I got two (2) pieces done and IT WAS A PAIN IN THE !!!!!! Ahhh I feel much better .

If it was not for the economics of it; I would have Noooo problem letting somebody else do the work.

Next week I plan to do the other two (2) "long" pieces of the frame (1800 mm long); after that I hope my wood skills have substantially improved since
I will attempt to make the "short" sides (1200 mm long) which, by the way, will be visible to the eye.

Have a great weekend everyone



Sincerely,

Useg Diaz-Granados

depends... leaving open the back a reasonable distance from the wall would likely improve things. too far out (say > 1m) may end up less effective.

_________________
Glenn

Q) Glenn, just want to check and make sure that I get you right.
Less then a meter from the wall with an open back is OK?
Or is it the other way around?

Sincerely,

Useg Diaz-Granados