High Efficiency Speaker Asylum

Posted by JRutter (i) on July 19, 2000 at 22:21:00:

In Reply to: Re: Thanks for the idea! (and) posted by GM on July 19, 2000 at 21:54:51:

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Yeah, 4" drivers are a little big to run full range. Try impedance compensation before you decide on a tweeter.
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I'll try to round up the parameters to do a zobel. If that helps even a little, I'm happy without the tweeter.

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Offsetting the drivers 1:1.6 will work, though I'm thinking offsetting them all the way to the edge may be better. Can you do a decent FR of just one driver in free air?
Baffle width/shape is dependant on the driver's response, and how big can you tolerate it.
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See link for Bob Fitzgerald's measurements. He has posted to the bottlehead forum that some foam tape applied to the outside edge of the driver at the surround interface took care of nearly all of the peak above 6 KHz. I've also read that a bead of elmer's glue in this area might help (and be easier to apply).

Also some FR data here:
http://f18.parsimony.net/forum31999/messages/2350.htm

I actually used approx. the same ratio to position them on the baffle. Right now it is 18" wide w/ driver centers at 7.5" from inside edge. Is the reason for pushing them completely to one side to spread the dips in response or help imaging, or both or neither?

Could you hit on some of the pros and cons of various baffle dimensions and shapes? I think that I understand edge diffraction, but with an open baffle the phase effects complicate things.

Many thanks,
JR

Follow Ups:

• Re: Thanks for the idea! (and) GM 19:57:13 07/20/00 (0)
• Missing link JRutter 22:23:14 07/19/00 (0)