Re: Various questions regarding 7Pi [message #86153 is a reply to message #86143] |
Wed, 20 September 2017 10:48  |
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Wayne Parham
Messages: 18889 Registered: January 2001
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Illuminati (33rd Degree) |
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The walls don't need to be rigid; In fact, a lossy wall is best. Just not one that buzzes as it vibrates.
The reason we like a lossy wall is it damps room modes. Ideally, we'd like a wall that became increasingly rigid above the Schroeder frequency, around 200Hz. Below that, we'd prefer that the wall act as a panel absorber.
As for items in the room, of course, the only real answer I can give is "it depends." Not what you were looking for, I'm sure. But it's true. Still, common sense works here. If the bookshelf only extends away from the wall into the room a foot or so (as I would expect), then it's probably fine. We aren't really concerned about radiation at that grazing angle anyway.
But if the shelves shadow the listeners, then obviously, that's bad. Or if it vibrates or something on it reflects towards a listener. Books on the shelves usually act as diffusers, which tend to be a good thing. But if you have some large smooth rigid object on the shelves that reflects from the tweeter to the listeners, that would really be noticeable. It would create a phantom source and throw imaging off.
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