In Nelson's article Current Source Crossover Filters he spells out that with a current source amplifier if we want a speaker crossover it has to be radically different than that used for a more traditional amp. But what do we do if we
have an amp that has a high output resistance like the F2 with it's 15 ohm output impedance do we use a traditional crossover or a current source crossover?
have an amp that has a high output resistance like the F2 with it's 15 ohm output impedance do we use a traditional crossover or a current source crossover?
True current source amp has output impedance (Zo) = infinite ohms.
15 ohms is closer to zero than to infinity.
Traditional transformer output tube amps have ~2 ohms Zo and they use XO designed for voltage source. They usually add impedance correction (zobels and resonance filters) which pure voltage amps don't need.
Back in the early hifi days, tube amp output impedance was higher than today, speakers were 16 ohms nominal load. They still used the voltage source model, but also crossovers were always designed by ear, T/S parameters didn't exist yet.
I would start with XO designed for voltage source, add filters to flatten system impedance, then tweak it by ear or FR measurement.
I have never heard of a computer simulator for passive crossover for current source, but maybe LEAP? $$
Of course, you can use active current source amplification to each impedance corrected driver, then use line level crossovers with voltage source drivers. This is all discussed in detail in the book, "Current Driving of Loudspeakers."
15 ohms is closer to zero than to infinity.
Traditional transformer output tube amps have ~2 ohms Zo and they use XO designed for voltage source. They usually add impedance correction (zobels and resonance filters) which pure voltage amps don't need.
Back in the early hifi days, tube amp output impedance was higher than today, speakers were 16 ohms nominal load. They still used the voltage source model, but also crossovers were always designed by ear, T/S parameters didn't exist yet.
I would start with XO designed for voltage source, add filters to flatten system impedance, then tweak it by ear or FR measurement.
I have never heard of a computer simulator for passive crossover for current source, but maybe LEAP? $$
Of course, you can use active current source amplification to each impedance corrected driver, then use line level crossovers with voltage source drivers. This is all discussed in detail in the book, "Current Driving of Loudspeakers."
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