If I change my Altec hf driver's diaphragms from 8 to 16 ohm, how much effect on the crossover point can I expect ?
I am using a 1st order XO with just a 5uf cap .
I am using a 1st order XO with just a 5uf cap .
If one driver really is 8 ohm at the frequency of x-over and the other really is 16 ohm at double the frequency, and the impedance traces looks otherwise similar - the effect will be double the x-over frequency. So e.g. 2kHz -> 4kHz etc...
In your case you need either an 2,5 uF cap or two 5's in series for 2,5uF... to retain the same XO as with the 5uF cap.
Try this :
https://www.v-cap.com/speaker-crossover-calculator.php
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In your case you need either an 2,5 uF cap or two 5's in series for 2,5uF... to retain the same XO as with the 5uF cap.
Try this :
https://www.v-cap.com/speaker-crossover-calculator.php
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Thanks, I was trying to find a reverse calculator to try.
Should be pretty simple do trial and error with REW and listening.
I do not have anything to measure the impedance.
Should be pretty simple do trial and error with REW and listening.
I do not have anything to measure the impedance.
f = 1/2πRC, so 16 Ohms will cross at HALF the frequency that 8 Ohms does.
8Ω and 5uF -> 3.98KHz
16Ω and 5uF -> 1.99KHz
8Ω and 5uF -> 3.98KHz
16Ω and 5uF -> 1.99KHz
Won't the output level of the 16 ohm hf driver also be half of that of the 8 ohm hf driver for the same input level?
And this will disturb the balance with the lf driver.
And this will disturb the balance with the lf driver.
Higher impedance will pass more, filter less, regardless high-pass or low-pass. So parallel the 5uF with another for ~10uF.
Simplified formula 1st order filters:
HPF hz=(160khz/ohm)/uF
LPF hz=(160hz*ohm)/mH
(2nd order filters: in above, calculate uF, mH for XO frequency f=5khz/sqrt(uF*mH); then respectively multiply/divide uF, mH by the same 1<q<2 to get different curves Linkwitz-Riley, Butterworth etc.)
Simplified formula 1st order filters:
HPF hz=(160khz/ohm)/uF
LPF hz=(160hz*ohm)/mH
(2nd order filters: in above, calculate uF, mH for XO frequency f=5khz/sqrt(uF*mH); then respectively multiply/divide uF, mH by the same 1<q<2 to get different curves Linkwitz-Riley, Butterworth etc.)
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Hmm, don't have the 299, but the many decades long 288 series is no different, only loading a PWT at rated resistance, ditto the 1" 800-900 series, though in retrospect all were measured on expo horns, so guessing they wouldn't rise on pure WGs or at least not enough to matter. Never bothered to measure my 800 series DIY parabolic WGs and used textbook 1st order with no obvious sonic issues according to even my then youthful female 'test gear'. 😉