These are Rectify Series drop-in speaker systems for Rapido PA/PB locomotives. No modifications are required to replace the factory speakers.
 
Two different speaker systems are available:
 
The RAPO-PAXF-RC1 replaces the front-mounted stock speaker. For locomotives with roof lighting, it includes holes for the small lighting board to be secured to the speaker just like the stock speaker (see photos of example D&H model). Use the stock screws.
 
The RAPO-PAXR-RC1 replaces the rear-mounted stock speaker.
 
Both speakers secure with strips of mounting-tape under the side-wings or a strap of Kapton tape over the top and down both sides of the chassis.
 
These speakers are louder than the stock speakers, with only one of them easily equalling the volume-output of both stock speakers. If you decide to install only one of these speakers, choose the front-mount version. I do not recommend installing only one of these while keeping one of the original speakers. While it will work fine, the poorer sound quality of the remaining stock speaker will muddle-up the benefits gained by the Scale Sound Systems speaker. If you want two speakers in your PA/PB, make them both Scale Sound Systems.
 
Note the photo indicating which PCB pads are the front and rear speaker positive/negative terminals. Be sure the two speakers are wired in-phase for proper sound.
 
The speakers come fully assembled and tested.
 
Dimensions are:
 
RAPO-PAXF-RC1: 17mmH x 22mmW x 40mmL
RAPO-PAXR-RC1: 12mmH x 22mmW x 40mmL
 
VIDEO: https://youtu.be/IiWXTj1vqFg