Originally Posted by
Ian Mackenzie
As long as you only have one connection from the battery negative terminal to the crossover negative terminal at the input you are fine.
Each capacitor junction should have its own + positive wire in series with a 2 -3 Meg ohm resister. The other side of the resister goes to the battery + positive.
Leave the battery ON all the time.
The capacitors take a few minutes to charge up.
On a practical level tension then builds up on the foil dielectric windings minimising foil chatter which otherwise modulates the capacitance blurring the sound. The dc voltage also biases the capacitor creating the so called zero crossing class A operation (refer to JBL literature M9500)
If you ever wondered is that a myth run the crossover into a dummy load with a music signal. You can hear the capacitors “sing”. It’s not rocket science. Valve amplifiers have very high DC bias voltages and the dc blocking capacitors are charge coupled the same way. Spare a thought for why valve preamps have that distinctive revealing sounbuiltd.