As per a member's request -
The following capacitors in the JBL Model 5234A can benefit from 0.01uF poly film and foil bypass capacitors:
C1, C2, C3, C4, C5, C6
C101, C102, C103, C104, C104, C106
The schematic is located in the back of the manual which can be downloaded here:
http://www.jblproservice.com/pdf/Vin...A%20manual.pdf
Here is the voltage drive of the 18dB/octave 51-5145 crossover card designed to be used for the 4344, 4345, and 4355 Studio Monitors. Also included is the voltage drive of the 12dB/octave 52-5140 card designed for the 4343 and 4350 Studio Monitors. The 51-5145 is ~ 3 dB down at ~ 290 Hz and the 52-5140 is ~ 4 dB down at ~ 255 Hz: