Which angle must to be between the walls?

murphy077 · Post by **murphy077** » Fri Jul 18, 2003 8:52 pm

Hi I'm David.

Which angle ( 10º, 20º...) must to be between the walls for to prevent the
paralel walls???

Thanks a lot.

knightfly · Post by **knightfly** » Sat Jul 19, 2003 12:53 am

Murph, John's tried different angles and found that 6 degrees per wall for a total of at least 12 degrees solves the flutter echo problem - For 6 degrees off square, that works out to almost exactly 1 foot in 10 for splay. So, a pair of 10 foot walls would end up 2 feet farther apart at one end than they were at the other end... Steve

murphy077 · Post by **murphy077** » Sat Jul 19, 2003 7:28 pm

Thanks for your answer Steve!!

One more little question..

.. I must to make the same with the ceiling?? Or are some other degree for ceiling??

thanks a lot.

David

knightfly · Post by **knightfly** » Sun Jul 20, 2003 2:44 am

Yeah, David, the physics are the same for vertical sound waves as they are for horizontal - the only difference is, since we aren't too comfortable walking up and downhill, the floor needs to be level. So ceilings need to be at least 12 degrees by themselves to get enough angle for flutter control.

Usually, to keep from having such a difference in ceiling height from one end of the room to the other, people make the CENTER of the room the peak (front-to-back) - otherwise, there would be a difference in ceiling height (assuming a 25 foot long room) of 5 feet. This would make for a more expensive building, or lower ceilings in an existing spot.

Peaking the ceiling in the center would mean that same room would have only 2-1/2 feet of height difference, with the same amount of flutter control... Steve

Post by **John Sayers** » Sun Jul 20, 2003 11:43 am

Just a point here - if the opposing surfaces are untreated at 6 degrees you hear the flutter echoes but if one of the surfaces is say lined with 703 - you won't hear them. That's my experience anyway.

cheers
john