Arena of Stars Stadium - Genting Highland
Case study - Kitaro Concert 16th October 2004
The stadium was surprisingly "controlled". Not reverberant. The sound produced from the speakers far away could reach the audience sitting at the last row (furthest) nearly crystal clear.
Originally I didn't pay any attention because I did not have any faith in the stadium at all. The loudspeaker array setup was not optimized from acoustics engineering "certain" point of view.
From a basic look the stadium's structure does not look like it was optimized for audio / acoustics transmission performance / consideration.
However after I listened to Kitaro for 30 mins I start to notice and realize the sound are "considered" direct without "MUCH" reverberant interference of a large space such at this. I was very puzzled and can't help look around for clues as to why and where are the acoustics treatment if any is applied.
The concert was generally dark and I could not see anything.
During this time I notice there were allot of reflections from the left and right side walls. I quickly conclude there were no absorption on the side walls. The large crowds sitting on the ground plan serves as a good acoustics absorption of 40% as well as provide around 50% of non coherent reflections, where our odd shapes helps to disperse sound in all different directions to stop standing wave built up. Sound passing through front rows to rear rows also travel in "diffraction" manner which reduces it's energy significantly and does not reflect to cause the "echo" effect.
At the last 30 mins of performance, more lights were used and due to long hour tiredness I finally found the reason for good acoustics performance in the stadium. The ceiling was completely used to hang long lengths of fabric of at least one (1) inch thick and no more than three (3) meter long across from left to right and front to back spacing only around 1 meters apart. This is allot allot of fabric. No wonder there was no reflection from the ceiling. See the white cloth like thing below.
Notice the black banner. They are also acoustics absorption material and they are allowed to turn / spindle at their position. Not only do they provide high amount of "areal" absorption like the white type above. These un-even movement helps to disperse sound in a "diffused" manner, which is much like our home or office or shopping space.
Bravo to the people who made this setup. My salute to your simple but effective method.
The side wall problems can be solved in the same manner by installing multiple FINS from two (2) meters from the floor all the way up to near ceiling. They should be install from front to rear one (1) meters long from the wall, spaced between one to two meters front to back. Cheap and effectively.
Kitaro Concert Live in Arena of Stars Stadium - Genting Highlands - Malaysia 16th October 2004
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