[Updated on: Sun, 26 April 2009 14:27]

Ivan Beaver wrote on Sun, 26 April 2009 19:15

...There is no "free lunch".

Ummm...

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Phillip Graham wrote on Mon, 27 April 2009 15:06

Mac Kerr wrote on Sat, 25 April 2009 17:46 How the array behaves is very dependent on frequency. It is also very dependent on the environment. The difference delay makes with no walls is easy to understand, and seems very controlled. When you add in the reflecting surfaces of the room the whole picture changes. It is easy to see why it is not so easy to make this all work in the real world. Mac Hey Mac, Two points of subtlety, even though the point of these graphs should not be lost on anyone. First, MAPP gives no consideration of the third dimension, which can/will change the locations of the nodes and antinodes, The diagrams can be thought of only as accurate in 2d.

True, I think I mentioned that here.

Phillip Graham wrote on Mon, 27 April 2009 15:06

Second, MAPP gives you no control of the stiffness and losses of the room boundaries. I don't know the values that Meyer has chosen, but they may or may not reflect reality. Simple (ie unrealistic) boundary conditions is typically computationally expedient, so that might be what Meyer is doing. I am sure Perrin or one of their other modeling guys could chime in on that.

Mapp does give you some control over the surface as shown in the image below. What I have not been able to make it do is make the architectural guidelines be surfaces. As far as I can tell you are limited to the box shape, although you can set the dimensions of the box. Since it is not 3D those details may be irrelevant anyway.

Mac

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[Updated on: Mon, 27 April 2009 15:22]

Kevin Windrem wrote on Sat, 25 April 2009 13:35

Christian Tepfer wrote on Fri, 24 April 2009 11:24 ... Spacing in between the subs eases the beam as well... MAPP seems to indicate increasing spacing between subs (with no delay tapering) NARROWS coverage (until the spacing gets too large, then you start seeing cancellation). 12 tight packed subs is already pretty narrow.

Kevin, this is correct globally in the half-sphere of coverage, but what Christian is suggesting can work practically for narrowing out the main coverage lobe.

Say you have a festival setting where all of the patrons are essentially contained in a rectangle as wide as the main stage (IOW in between the PA hangs). Here, if you don't have enough subs to make a solid horizontal array across the entire stage front, but instead you spread them out a few feet on center, the practical result will be a wider main lobe (in between the PA towers).

If the audience spills well outside of this width, like in the arena being discussed, then of course a different sub deployment is in order.

So its possible for you both to be right depending on the needed deployment

[Updated on: Tue, 28 April 2009 10:16]

Could anybody post a closer photograph of those CLAIR's subwoofers please?

A pdf with it's specifications could help too.

Thanks.

Just in advance: I'm not of the "cloning guy" type.

This is a jpeg file of what I do:

It's made with 4 EAW's SB-1000 and I name it "Wide Cardioid Subwoofer"

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[Updated on: Tue, 28 April 2009 00:59]

There are no published specs for those subs, but here's a closer shot of them:






FWIW- We have the subs center clustered with them now delayed and life is good. The bass spreads out a lot more, and still hits plenty hard up the middle. I think this is what we're going to stick with.



Evan

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