[japanesegeek]

If I put a wall of acoustically transparent GOM in front of my front and center speakers, and have an electrically retractable microperfed screen in front of that will it still be transparent (or do I need to do more then that)?


I see that GOM comes in 66" strips. I'll need a little less then twice that to reach the ceiling of my home theater room. My thought is to attach it to the walls with velcro so I can get to the speakers to replace them and such. My wall is just 15' wide so I'm thinking that the velcro should be strong enough to tension the GOM and hold it in place since I don't want to add any other support and interfere with my speakers. That sound like the best approach?

 

[Toxarch]

It would be cheaper to frame a wall, attach a fixed microperf screen and then cover the rest on in GOM. Also, make a hidden door or removable panel to access behind the screen. I think some even remove their screen to get access behind it. An electric microperf drop screen isn't the cheapest option to purchase. Put all the speakers behind the screen, and you don't worry about any framing blocking your speakers.

 

[Terry Montlick]

Micro-perf screens are not completely acoustically transparent at high frequencies. Since you will need to equalize anyway for the high frequency attenuation of the screen, the Guilford fabric does not pose a problem.


Regards,

Terry

 

[japanesegeek]

I considered building the screen into the wall with my speakers behind it, but unfortunately my two boys (ages 1 and 3) are fond of touching (and, on at least one occasion, even hitting) the plasma television I have in the family room. I'm concerned that if the screen gets greasy it won't wipe clean like the plasma does. Hopefully I'm mistaken about that. I've still got 6 to 8 weeks before my home theater room is otherwise completed so I still have time hopefully to get educated more on screens.


If I do go the route of buying a fixed screen and integrating a GOM wall around it, how do I attach the screen to the frame? And would I want to avoid screens that have a border since it will be a different shade of black then the black GOM, or will black fabric all look the same with the lights off?

 

[japanesegeek]

Quote:

Originally posted by Terry Montlick Micro-perf screens are not completely acoustically transparent at high frequencies. Since you will need to equalize anyway for the high frequency attenuation of the screen, the Guilford fabric does not pose a problem. Regards, Terry

You'll, hopefully, forgive my total lack of acoustical knowledge. If the screen isn't completely acoustically transparent, how do I get the information back? Is the information not lost and I'm just transforming one frequency to another frequency so that when it hits the screen it gets transformed back to the first frequency?

 

[Terry Montlick]

Okay, here's how it works. No frequencies get transformed. Sound at a given frequency simply doesn't fully penetrate the screen. Some of it is reflected back, and never makes it through the screen.


All micro-perf screens reflect some sound at the highest audio frequencies. Low frequencies hardly even "see" the screen. Their wavelengths are so big compared to the thin screen material that they travel completely through, unaffected. Still higher frequencies would be blocked by the screen, but the perforations let them through. But even though the screen is thin and the holes tiny, the very highest frequencies don't make it through 100%. This can amount to several decibels loss at the highest audible frequencies.


You need to give these frequencies a boost so that they are at the same level as if the screen were not there. This high frequency boost is provided by an electronic equalizer. Stewart screens come with a fixed equalizer matched to their screens. Other micro-perf screens will need a separate equalizer in order to restore the high frequencies to their original levels.


Regards,

Terry

 

[japanesegeek]

Thanks! Great explanation.