Q & A: Power Alley Problem
I'm told by an acoustical consultant that we have a power alley problem. What does that mean, and how can we fix it?
Q. Our church has a fairly large sanctuary (seats 1,500), and we have a large sound system that reinforces a fully electronic Christian-rock praise band. I'm told by an acoustical consultant that we have a “power alley” problem. What does that mean, and how can we fix it?
A. You must have left- and right-positioned subwoofers. A “power alley” describes a situation where only a narrow center line of a left and right subwoofer system gets interference-free bass. This is caused by cancellation effects of the two interacting sources. The width of the alley depends on how far apart the subwoofers are positioned. The greater the separation, the more narrow the “alley.” The only way to totally avoid a power alley is to keep all subwoofer sources together, as in a cluster.
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