3 Way Active Crossover
rlecuyer
Posts: 3
I am going to build a Tri-Amp system. I'll be building the 6 amplifier system in house over the summer and it should go very well. I am trying to design an active crossover system so that I can split the signal up into Low, Mid, and High frequency ranges (break points are at about 220 Hz and 1800 Hz). Although when I simulate my crossover setup the signals become heavily out of phase (70+ degrees). Is this something I should bother fixing electronically or should I just space the speakers apart from each other accordingly? Here's a few pictures to show what I want to do:
http://www.uvm.edu/~rlecuyer/
It's a very simple crossover. I will be replacing the input impedances of my amplifiers with these crossovers, and perhaps adding another Highpass to the Low frequency and a Lowpass to the High frequency to remove unwanted signals below 20Hz and above 20KHz. Also, this is the first time I will be playing with inductors in the signal line, I heard that you should only use Air-core inductors to provide for the best sound quality. Is this what I should use and what else should I look for when buying my inductors? How much should I worry about inductor layout when I draw up my PCB (electromagnetic fields)? Is spacing them 4-5 cm away good enough or should I shield them/separate them more?
Also, I read some rumors that a Zobel network is not required in an active crossover which may have lead me to believe a different purpose for the Zobel network. To my understanding a Zobel network helps remove reactive loading on the output of the amplifier due to the speaker's reactive components (thus providing better linearity).
http://www.uvm.edu/~rlecuyer/
It's a very simple crossover. I will be replacing the input impedances of my amplifiers with these crossovers, and perhaps adding another Highpass to the Low frequency and a Lowpass to the High frequency to remove unwanted signals below 20Hz and above 20KHz. Also, this is the first time I will be playing with inductors in the signal line, I heard that you should only use Air-core inductors to provide for the best sound quality. Is this what I should use and what else should I look for when buying my inductors? How much should I worry about inductor layout when I draw up my PCB (electromagnetic fields)? Is spacing them 4-5 cm away good enough or should I shield them/separate them more?
Also, I read some rumors that a Zobel network is not required in an active crossover which may have lead me to believe a different purpose for the Zobel network. To my understanding a Zobel network helps remove reactive loading on the output of the amplifier due to the speaker's reactive components (thus providing better linearity).
Post edited by rlecuyer on
Comments
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Your simulation is of a passive crossover not active.What is the load, the input of the amp?An active uses opamps that buffer the small precision capacitors and resistors used for setting filter frequencies.I am going to build a Tri-Amp system. I'll be building the 6 amplifier system in house over the summer and it should go very well. I am trying to design an active crossover system so that I can split the signal up into Low, Mid, and High frequency ranges (break points are at about 220 Hz and 1800 Hz). Although when I simulate my crossover setup the signals become heavily out of phase (70+ degrees). Is this something I should bother fixing electronically or should I just space the speakers apart from each other accordingly? Here's a few pictures to show what I want to do:
That is true but for a normal passively crossed over speaker.Also, this is the first time I will be playing with inductors in the signal line, I heard that you should only use Air-core inductors to provide for the best sound quality.
Zobels are not required with active crossovers.When a Zobel also known as an impedance equalizer is used on a driver(RC across the voice coil)it will negate the voice coils inductance.This inductance usually causes the impedance of the driver to increase incrementally as frequency increases.The resulting equalized impedance brought about by using a properly designed Zobel will make the driver appear more like a resistor to the passive crossover network.Also, I read some rumors that a Zobel network is not required in an active crossover which may have lead me to believe a different purpose for the Zobel network. To my understanding a Zobel network helps remove reactive loading on the output of the amplifier due to the speaker's reactive components (thus providing better linearity).Testing
Testing
Testing
