http://home.new.rr.com/zaph/audio/audio-speaker11.html
ok,
in that article he noted how including the notch filter helped clean up the midrange and provided response graphs
I don't quite understand how he came up with the values for the components....I've looked into PNF and did the formula and still don't get close to what he does...nor do I understand how the graph with the filter(3rd graph from the top) seemed to smooth out over such a wideband(1khz to 10khz)
ok,
in this unfiltered onaxis graph am I right in assuming a -3db point at 1200hz and 3000hz?
maybe another at 10khz and 13khz...can you do multiple PNF?
thanks
ok,
in that article he noted how including the notch filter helped clean up the midrange and provided response graphs
I don't quite understand how he came up with the values for the components....I've looked into PNF and did the formula and still don't get close to what he does...nor do I understand how the graph with the filter(3rd graph from the top) seemed to smooth out over such a wideband(1khz to 10khz)
An externally hosted image should be here but it was not working when we last tested it.
ok,
in this unfiltered onaxis graph am I right in assuming a -3db point at 1200hz and 3000hz?
maybe another at 10khz and 13khz...can you do multiple PNF?
thanks
Any inductor and capacitor that resonate at ~2kHz will work to make your notch.
(2*pi*F)^2=1/(L*C)
Example: If you want to use .6mH
C=1/((2*pi*F)^2*L)
C=1/((2*pi*2000)^2*.0006)=10.5e-6 Farads (10.5uF)
You would then have to select a suitable Resistor, probably best done by trial and error but you could calculate a number. - you won't need much of one - a few ohms
If you had a different inductor on hand you do the formula again.
---------------
Notch filters can cause problems with some crossovers, what is the crossover circuit and how close to the xo frequency? Being that you only need a slight notch, it may not cause problems - but you could possibly remove the peak if it is due to tweeter resonance (impedance peak) by putting a series notch in parallel with the tweeter.
BTW, don't try to notch the 10kHz peaks, it would be a waste of time.
(2*pi*F)^2=1/(L*C)
Example: If you want to use .6mH
C=1/((2*pi*F)^2*L)
C=1/((2*pi*2000)^2*.0006)=10.5e-6 Farads (10.5uF)
You would then have to select a suitable Resistor, probably best done by trial and error but you could calculate a number. - you won't need much of one - a few ohms
If you had a different inductor on hand you do the formula again.
---------------
Notch filters can cause problems with some crossovers, what is the crossover circuit and how close to the xo frequency? Being that you only need a slight notch, it may not cause problems - but you could possibly remove the peak if it is due to tweeter resonance (impedance peak) by putting a series notch in parallel with the tweeter.
BTW, don't try to notch the 10kHz peaks, it would be a waste of time.
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