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Multi-Way Conventional loudspeakers with crossovers

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Old 19th November 2010, 02:01 PM   #4981
doug20 is offline doug20  United States
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Quote:
Originally Posted by ZilchLab View Post
I recall advising Markus to get rid of his couch and sit on the floor, and also being very much dismayed that he did not consider this obvious remediation to be a workable solution....
I guess designs like Duke's audiokensis designs or Emeral Physics designs will sound horrible with that larger CTC. I guess those and speakers from Geddes just do not make the audiophile grade BUT a JBL horn + Selenium D220 CD does???? I guess Im missing the disconnect here.
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Old 19th November 2010, 05:58 PM   #4982
badman is offline badman  United States
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Originally Posted by doug20 View Post
I guess designs like Duke's audiokensis designs or Emeral Physics designs will sound horrible with that larger CTC. I guess those and speakers from Geddes just do not make the audiophile grade BUT a JBL horn + Selenium D220 CD does???? I guess Im missing the disconnect here.
Doug, you're sure acting strangely here lately, seeming to want to pin things down into absolutes. No absolutes exist in audio, (or in most things). The geddes compromises are different from those of "Econowave" and each will have their proponents. I'm surprised none of the other Ewavers have tried my foam solution- there's obvious ripple at cutoff with that horn and it's well controlled with my foam without expanding CTC...
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Old 19th November 2010, 06:52 PM   #4983
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.....I'm surprised none of the other Ewavers have tried my foam solution- there's obvious ripple at cutoff with that horn and it's well controlled with my foam without expanding CTC...
Do you have a link to your earlier posts on the type of foam you use and how you use it?

I'm using a round WG from DDS. Will this have the same problems as the rectangular WGs?

I've tried a few foams in different configurations and find none sound best in my case.

Thanks
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Old 19th November 2010, 08:30 PM   #4984
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Quote:
Originally Posted by doug20 View Post
I guess designs like Duke's audiokensis designs or Emeral Physics designs will sound horrible with that larger CTC. I guess those and speakers from Geddes just do not make the audiophile grade BUT a JBL horn + Selenium D220 CD does???? I guess Im missing the disconnect here.
I'm not saying any of that, rather, merely that there is a set of known parameters within which rational tradeoffs and compromises may be made toward an optimized design. Yes, there are performance differences between $200 builds and $2000 ones, but done intelligently, either can produce a satisfying result, and those differences are not so huge as to deter any DIYer from beginning at the entry level and learning the basics hands-on.

We all started the same place here -- Wayne, Duke, Earl, myself, and others -- with David Smith's (who posts in these forums) and Don Keele's JBL 4430 defining the fundamentals of constant directivity loudspeaker design. It's basically open forum, and there's a lot of cross-pollination occurring as we each put our own "spin" on implementing and refining the concept, and debating the merits of different approaches, to everyone's benefit and advantage....

Last edited by ZilchLab; 19th November 2010 at 08:40 PM.
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Old 19th November 2010, 09:33 PM   #4985
JoshK is offline JoshK  Canada
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curious if anyone's uncovered the math behind the prolate spheroidal coordinates (aka elliptical OS)? Given the equations, it seems one could make a form to reasonable proximity and cast waveguides.
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Old 19th November 2010, 09:34 PM   #4986
jzagaja is offline jzagaja  Poland
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After having some experience with with OS and JMLC (CD vs. non-CD) I pay more attention to cover midrange from 200Hz to 5KHz in one horn using compression driver. Good candidate for both worlds - CD-JMLC "midrange" plus GAMT90.
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Old 19th November 2010, 09:38 PM   #4987
badman is offline badman  United States
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Originally Posted by makingmoney View Post
Do you have a link to your earlier posts on the type of foam you use and how you use it?

I'm using a round WG from DDS. Will this have the same problems as the rectangular WGs?

I've tried a few foams in different configurations and find none sound best in my case.

Thanks
Geddes on Waveguides
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Old 19th November 2010, 09:59 PM   #4988
JoshK is offline JoshK  Canada
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I think I found the math. What we are looking for is ellipsoidal coordinates, not prolate spheroidal coordinates.

Confocal Ellipsoidal Coordinates -- from Wolfram MathWorld
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Old 19th November 2010, 10:01 PM   #4989
JoshK is offline JoshK  Canada
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hmm...don't think that is right either, cause the "throat" doesn't reduce to a circle.
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Old 19th November 2010, 11:35 PM   #4990
bwaslo is offline bwaslo  United States
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Originally Posted by badman View Post
I'm surprised none of the other Ewavers have tried my foam solution- there's obvious ripple at cutoff with that horn and it's well controlled with my foam without expanding CTC...
It's on my to-do list.
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