Testing Speakers

First, it is crucial to determine which model of audio drivers are being tested. Then, disconnect the outside speakers from the two terminals on the back of the amplifier. Put a DC ohm meter across the leads going to the tower. If the reading is higher than the listed value, then one or more of the drivers could be open, or a connection is corroded. If lower, one or more drivers or the wiring may be shorted.

Determine the resistance of the Ohm meter's own leads by touching the two test leads together. Subtract the displayed value from measurements before comparing to those given below.

SJTO-14 wire supplied by chime master will add about 0.0056 ohms per foot to the driver reading.

PD60A Drivers

PD60 Drivers

  • Single functional PD60 driver will read 9.5 - 10ish ohms directly from the terminals on the driver, not including any wire
  • Four PD60 drivers will read 2.5ish ohms when wired together in parallel with a short length of wire
  • Two PD60 drivers together will read 5ish ohms when wired together in parallel with a short length of wire
  • Four PD60 drivers wired into a speaker line roughly 250ft. in length will read 3.8ish ohms
  • Four PD60 drivers wired into a speaker line that is 25ft. will read 2.7ish ohms

SD60 drivers

SD60 Drivers

  • Single functional SD60 driver will read 9.5 - 10 ohms directly from the terminals on the driver, not including any wire
  • Four SD60 drivers will read 2.5 ohms when wired together in parallel with a short length of wire
  • Two SD60 drivers together will read 5 ohms when wired together in parallel with a short length of wire
  • Four SD60 drivers wired into a speaker line roughly 250ft. in length will read 1.4 ohms
  • Four SD60 drivers wired into a speaker line that is 25ft. will read 2.14 ohms

PD60AT Transformer Drivers

PD60AT Drivers

  • Single functional PD60AT driver will read 2.7 ohms directly from the terminals on the driver, not including any wire
  • Four PD60AT drivers will read .675 ohms when wired together in parallel with a short length of wire
  • Two PD60AT drivers together will read 1.35 ohms when wired together in parallel with a short length of wire