Film-Tech Forum ARCHIVE: Proper Baffle Wall Construction

This is topic Proper Baffle Wall Construction in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Lyle Romer (Member # 1266) on 05-09-2009, 05:31 PM:

I've done some searches and found some baffle wall related topics but I haven't found a "how to". What is the proper method of constructing a baffle wall? What material (and how much) should be used? For the black acoustic material, exactly what should it be and where do you get it? Is it just black painted ductboard?

Posted by John Walsh (Member # 168) on 05-10-2009, 12:01 AM:

There has been another topic on this, but I can't find it either.. Here's the quick and dirty of it cuz I'm tired .... You want to use steel 2x6's (or 2x8's if it's a bigger screen) for the frame; you can use aluminum but have to space them closer together. Three layers of 5/8" sheetrock, each individually screwed to the frame (no cheating and putting one screw through all layers.) The sheetrock should be placed overlapping, and tape the seams. If you look in the pictures section under the Glenview theater, there's a picture of a regular wall, but it gives you the idea. A layer of 2" ductliner fixed to the wall, from 'John Mansville.' A heavy sheet of rubber can be used to enclose the open area around the HF horn. Mason Super "W" 30 durometer pads for speaker feet. Make sure the screen frame guy (Nick) keeps the screen frame struts away from where the speakers will be. Except for the ductliner, paint everything back there flat black. Plan now on how you will design the wall, with hatches or whatever to change drivers when they go bad.

Posted by Louis Bornwasser (Member # 3063) on 05-10-2009, 06:09 AM:

The goal is to have a very massive wall that will not rattle if you pound it with your fist.

I have seen them made of books and even LP record albums (both in a cinema); perhaps the best would be solid concrete or even marble cemetery markers. (With a surface of duct liner.)

Back when cinemas had the speakers in dog houses sticking out the back of the building, the back wall of the building was "the sound wall."

I'm not trying to be cute, just trying to give you some ideas of how to use an existing situation you may have. Louis

Posted by Kenneth Wuepper (Member # 1174) on 05-10-2009, 08:27 AM:

Yes! Louis,

We had a Cinema & Suds that had 2 screens and the outside walls were block and brick. The screens were tight to the walls so the speakers were in masonry spaces outside the main structure. Looked a little funny from the street with three bumps sticking out of the walls of each theater.

The only way to access the speakers was to take down the screen!
Now that's real planning.

KEN