Motion Sound PRO-145 User Manual
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Rotors and Motors – No maintenance required.
Rotor Speaker – The Eminence speaker is a Beta 12” 8 ohm 250-watt. Remove the back cover
(19 screws) to gain access. All screws are in steel threaded inserts and the speaker wires are
removable spade lugs. If you replace the speaker use 8 ohm models only.
Horn Diaphragm – Only use a Motion Sound MS-1.2 diaphragm. Stock Eminence
diaphragms will quickly fail.
1. To gain access, remove the axle support on the cabinet top (3 screws).
2. Remove the rear cover (19 screws).
3. Remove the 4 screws from the top of the horn rotor assembly. (use a ¼” wrench)
4. Carefully move the horn assembly towards the rear of the cabinet (be careful of the
microphones) so you can easily remove the motor connector and the two spade connectors
from the diaphragm. Note the polarity and color of the wires.
5. Slide the rotating assembly through the top slot out of the cabinet.
6. Remove the 3 screws from the diaphragm.
7. Follow the instructions on the sheet sent with the replacement diaphragm.
8. Reassemble in reverse order; be sure to connect the motor plug so the orange wire is towards
the top. Place a small amount of silicone rubber to hold the connector in place.
Low Rotor Belt Adjustment – The motor, belt, and ball bearing rotors are carefully adjusted at
assembly and require no maintenance. If you notice any belt noise, you can tighten the belt by
loosening the two screws on the motor mount and sliding the motor assembly away from the
speakers. DO NOT over-tighter the belt. Tension just enough to stop slipping or noise and no
more. The Polyurethane belt will last a very long time if properly adjusted.
Tube
1. Remove the rear cabinet cover (19 screws).
2. Loosen the tube holder bracket and rotate it aside.
3. Remove the tube from the socket.
4. Replace only with a gain selected tube such as: 12A7EH or GE 5751 N.O.S.
5. Detailed tube information is on our web s
tech & legacy.
6. Normal tube life in the PRO-145 is 5 years or more.