How I built my CR window

[John White]

Thanks for sharing your project. The construction looks solid.

What do you mean by the spacing of the rubber changing the resonant frequency?
The mass of the glass would certainly effect the FR.

Also, what is your glass spacing and what TL did you achieve? 7"?
It must be significant with the 1/2"

[AdAudioInc]

Originally Posted by John White

Thanks for sharing your project. The construction looks solid.

What do you mean by the spacing of the rubber changing the resonant frequency?
The mass of the glass would certainly effect the FR.

Also, what is your glass spacing and what TL did you achieve? 7"?
It must be significant with the 1/2"

Hey John.
The spacing of the rubber is theoretical, but I think it should have some minor effect. Ideally I would have used 2 glass panes of differing thickness - these came from my brother in law for free, so I took what I could get - both 1/2" - both with the same resonant frequency, because of the same size and same mass. When the controlroom glass was placed in the frame it was set on 2 rubber mounts about 1/8" thick, each about 2" from the bottom corners of the glass. We then set the Studio side the same way, only moved the rubber mounts about 5" in from the corners. The theory being that because the glass is resting on different points, it will resonate differently from the other pane.

The space between the 2 panes is about 7" at the bottom, tapering to about 5.5" at the top. I do not have any measurements yet, but will post them when I get something.

'Frank

[Rod Gervais]

Nice looking build - and I'm sure you will get some decent isolation with the system you used.

Just a few comments in conjunction with John's question:

The mounting will not affect the resonant frequency of the glass - this is based on the mass and size of the panel - and has nothing to do with the method used to support those panels......

The fiberglass "stop" you installed between the panels is an excellent method to provide a dust free environment for the windows while maintaining maximum isolation between the leafs - but it will not prevent resonance within the cavity.

But a very nice build for sure.

Congrats,

Rod

[avare]

+3 on the nice build!

Andre

[AdAudioInc]

Originally Posted by Rod Gervais

Nice looking build - and I'm sure you will get some decent isolation with the system you used.

Just a few comments in conjunction with John's question:

The mounting will not affect the resonant frequency of the glass - this is based on the mass and size of the panel - and has nothing to do with the method used to support those panels......

The fiberglass "stop" you installed between the panels is an excellent method to provide a dust free environment for the windows while maintaining maximum isolation between the leafs - but it will not prevent resonance within the cavity.

But a very nice build for sure.

Congrats,

Rod

Thank you for the kind comments. I am curious as to why the fiberglass would not help reduce resonance - basically, sound that does make it between the glass gets absorbed - rather than bounced around - no?

[Rod Gervais]

Originally Posted by AdAudioInc

Thank you for the kind comments. I am curious as to why the fiberglass would not help reduce resonance - basically, sound that does make it between the glass gets absorbed - rather than bounced around - no?

My pleasure - it really is a beautiful build -

What you're talking about here would be similar to room treatments in your mind - you absorb the reflections and thus lower the resonance of a room..

When it comes to absorption - you would need much larger quantities than that small strip of fiberglass to create any effective absorption..... and what little sound might pass through the crack between those 2 walls (which will in some small part be absorbed by the much larger quantity of fiberglass within the wall itself) - after it passes through the fiberglass trim strip - is relatively small as well.

These systems work simply based on the decoupling effect of the walls - as well as the mass of the glazing - and in your case - a little extra beef due to the fact that you have laminated glass.

The fiberglass strip is a manner of handling the void between the a frames while maintaining a decoupled assembly- just a very clean neat & effective architectural detail......

Rod

[AdAudioInc]

Originally Posted by Rod Gervais

My pleasure - it really is a beautiful build -

What you're talking about here would be similar to room treatments in your mind - you absorb the reflections and thus lower the resonance of a room..

When it comes to absorption - you would need much larger quantities than that small strip of fiberglass to create any effective absorption..... and what little sound might pass through the crack between those 2 walls (which will in some small part be absorbed by the much larger quantity of fiberglass within the wall itself) - after it passes through the fiberglass trim strip - is relatively small as well.

These systems work simply based on the decoupling effect of the walls - as well as the mass of the glazing - and in your case - a little extra beef due to the fact that you have laminated glass.



The fiberglass strip is a manner of handling the void between the a frames while maintaining a decoupled assembly- just a very clean neat & effective architectural detail......

Rod

Thank you for taking the time to explain - much appreciated.

'Frank

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