Hello, if the two-way passive crossover is originally second-order with tweeter reversed polarity, does converting it to fourth-order ACTIVE still necessitate reversing tweeter polarity? And vice versa for the original tweeter's non-reversed polarity.
Edit - add more info:
In my experience, reversing the polarity of the tweeter on second-order low-pass and high-pass filters resulted in a summing frequency response at the crossover region, whereas not reversing the polarity resulted in a “dip”. Assuming we want to keep the dip in the crossover region, we have to reverse the polarity of the tweeter when using fourth-order active. Is that correct?
Edit - add more info:
In my experience, reversing the polarity of the tweeter on second-order low-pass and high-pass filters resulted in a summing frequency response at the crossover region, whereas not reversing the polarity resulted in a “dip”. Assuming we want to keep the dip in the crossover region, we have to reverse the polarity of the tweeter when using fourth-order active. Is that correct?
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If a passive network has a second order topology, it is very likely that the net acoustical response is 3rd order or 4th order.
A second order topology has two reactive elements (inductors and caps). Shown below is a high pass
Are you looking to install an active filter and duplicate the response of the current passive filter?
A second order topology has two reactive elements (inductors and caps). Shown below is a high pass
Are you looking to install an active filter and duplicate the response of the current passive filter?
Yes, I am. I think this might be the best way to go because I’ve seen some active setups of commercial system did it, e.g., the vintage ADS C2000 electronic crossover, it has four selectable crossover settings uniquely programmed for their ADS speakers; L1230, L1530, L2030, and manually adjustable.
Unless this is an "add on" tweeter on top of a speaker system; you should not modify the filter of the tweeter alone.
As mentioned above, you should consider the response of the system to get the target response on air (filters+speakers), then you need to design both high pass and low filters to get it.
As mentioned above, you should consider the response of the system to get the target response on air (filters+speakers), then you need to design both high pass and low filters to get it.
To duplicate the response of the existing system, you will need a way to measure either:
(1) the electrical response that is presented to woofer and tweeter. You would drive the system with a sine sweep or a pink noise signal, and measure the frequency response at the driver terminals.
or
(2) the acoustic radiated response of the woofer and tweeter. You would use a measurement microphone and a software like REW to make frequency response measurements of the drivers as they are now.
(1) the electrical response that is presented to woofer and tweeter. You would drive the system with a sine sweep or a pink noise signal, and measure the frequency response at the driver terminals.
or
(2) the acoustic radiated response of the woofer and tweeter. You would use a measurement microphone and a software like REW to make frequency response measurements of the drivers as they are now.