Coral 12TX-1 Triaxial Speaker Crossover

[Rapala56]

I just obtained a pair of these speakers made by Fukuyo Sound around 1960. I want to replace the crossover capacitors, but values are not marked. Does anyone have this information? The company went out of business in the 80’s and I can’t find much information about this speaker.

 

[AllenB]

I would measure the filter responses before touching the caps, then pull them. Maybe there is writing on the other side. You could measure their capacitance then, but back it up with the responses. Then measure the sound pressures to help decide they are correct.

 

[Rapala56]

Thanks for your suggestion. Unfortunately, both capacitors measure open and neither are marked. I was hopeful that someone might have a schematic which shows the correct capacitance values. I have a Fluke meter, but no equipment for measuring sound pressures or frequency response.

 

[wolf_teeth]

Capacitors measure as 'open' on a standard DMM/VOM. This is because it takes AC to make them 'pass' signal. You need an LCR meter to check them for value, and maybe leakage.

Later,
Wolf

 

[chris661]

This depends on how much this project is worth to you. £100 gets you set up with a half-decent measurement rig with which you can design your own crossovers.

If you just want to replace the caps (IMO, simple highpass-only crossovers rarely work), then chances are the value will be written on the other side of the caps. You'll just need to extract them to read the values.

Chris