Caps apparently don't age well.
Oil filled? Bees Wax(!) and others can dry over long time periods.
Newer cap designs may pay dividends with better sound. Crossovers are a thing unto themselves. Some guru might even recommend dropping the iron core inductor, if so fitted, and go to air core.
You might want to replace the L-pads altogether with a fixed resistor after getting everything sounding right. Measure carefully!
Some speakers had (have?) a switch for 2 or 3 settings, with different resistor values to be switched into or out of the circuit as needed.
Oil filled? Bees Wax(!) and others can dry over long time periods.
Newer cap designs may pay dividends with better sound. Crossovers are a thing unto themselves. Some guru might even recommend dropping the iron core inductor, if so fitted, and go to air core.
You might want to replace the L-pads altogether with a fixed resistor after getting everything sounding right. Measure carefully!
Some speakers had (have?) a switch for 2 or 3 settings, with different resistor values to be switched into or out of the circuit as needed.