Speaker Asylum

Really?!!!!!!!!!

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This Post Has Been Edited by the Author

In Reply to: RE: Diffraction and front baffle and cabinet design posted by villastrangiato on April 17, 2012 at 11:59:56

"you'll find that the responses in figure 15,16, and 17 (the rectangular box) have the best response. The sphere with offset tweeter (figure 6) is not a practical design and you didn't specify an offset driver which makes a significant difference as the centered driver on a more practical circular baffle (figure 8) is the worst case (which is what I was referring to). "
A significant error. The drivers used were a single WR/FR driver, no tweeters. The sphere in Fig.6 is itself offset so that you can see the driver clearly. But the driver IS centred.
And why is that? Put a single driver on a sphere - anywhere - and it will be centred on the sphere by definition, as would any dot be, no!? Because you would measure it on axis, as with all the other shapes covered.
So, 'offsetting' a single driver on a sphere is simply impossible.
So, you are wrong. Fig. 6 - the sphere with a single driver, has the smoothest FR. Despite the driver being - inevitably - centred.
A sphere is not a circular baffle as it does not have an edge at all.
A circular flat baffle does have a sharp edge and would be pretty awful with a centred driver also by definition. Just by the way there are no Figs for a circular flat baffle on that page - for two conics? yes. The paper is about enclosures not open baffles.
Even a truncated sphere with a sliced (circular) baffle is measurably superior to a 90-degree edge box, and audibly so.
This audible superiority may have a secondary cause - that curved surfaces suppress bending waves / are self damping.
Practical / real spheres are truncated and thus do not have the predicted single/audible internal standing wave either. Just in case you want to bring that up.
It is true that for modern materials baffle truncation is not essential, yet Gallo's spheres still didn't have this single standing wave problem either, perhaps because all real drivers have volume. Eggs are theoretically better but are even more expensive to MFR even in volume.
Mind how you go. Especially with your commitment to particular points of view, eh? :-)
Do read the paper by Olson, all of it, twice. Then respond.
Eating some humble pie is in order.

Note that a post in response is preferred.

Warmest

Timothy Bailey

The Skyptical Mensurer and Audio Scrounger

And gladly would he learn and gladly teach - Chaucer. ;-)!

'Still not saluting.'

Edits: 04/18/12 04/18/12 04/18/12

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