In Reply to: RE: Alternative to the EV ST350 horn tweeter on EV Sentry IV-A's posted by Paul Eizik on October 29, 2013 at 20:33:54:
Paul,
I have a plan....I will go with the 3500hz, but with the Butterworth alignment rather than the X36 alignment. I brought the woofer/mid up to 550Hz, may help a woofer dip from about 250-400Hz. Comparing all of the available EDS FR plots, (lot's of assumption/extrapolation, since none really are the component mix in the Sentry's), I do think I will get the smoothest FR with this alignment. Thank you for pointing out the 1824M drop off above 2500Hz. The 1823M, with the PA horns, looks like that drop starts around 3000Hz to 3400Hz so that really focused the XO point.
I validated using the calculators in the link that you provided. It is more sophisticated, allowing the selection of an initial slope of 3dB or 6dB. (BTW, great link. Much good stuff there!! I saw why I was getting vastly different component values from different formulas and calculators! That's my handicap...good at math, weak on what the results mean acoustically in the real world!) If the EQ gets the ST350 10kHz -15kHz up eliminating the steep drop off, I will be a happy camper....and an EV purist!! ;-)
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I will go with this to listen/test/tweak. I have some 15ohm Mills 12W, (overkill) I can parallel for the 7.5ohm and caps from 2-3.3uf to try. I will probably start with a 2.2uf as I have some Russian mylar/paper/oil caps that may be perfect for the tweeter. So I have to hit Parts Express for the .18mH copper foils. Timing is everything...PEx sent me a "Come Back" 5% discount code!
Thanks again for your time and valuable input!!! If you have other thoughts it would be great to hear them.
Cheers,
Geary
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Follow Ups
- RE: Alternative to the EV ST350 horn tweeter on EV Sentry IV-A's - Geary Lyons 10/29/1323:01:17 10/29/13 (1)
- RE: Sounds like a good plan! - Paul Eizik 16:51:39 10/30/13 (0)