This is a Rectify Series drop-in speaker system for most Athearn Genesis locomotives that have a single 28mm speaker mounted in the weight behind the PCB. These models include the SD45-2, SDP45, various SD60-types, most of the SD70-types (not the MAc and not the ACe with a speaker behind the cab) and possibly other models.
 
The speaker uses the factory mounting and no modifications are required to replace the factory speaker.
 
To further enhance the sound of these units without making any modifications, I offer two different companion speakers that will fit behind the cab. Both of these replace the small weight screwed to this part of the frame.
 
The AHGS-2845-RC1 is designed for the SD45-2, SDP45, SD60i, SD60M and other models that have a tubular screw-post running down the inside of the shell.
 
The AHGS-2860-RC1 is designed for the SD60E and other models that do not have the tubular screw-post, with a clear opening available.
 
Adding these front-mounted systems is a simple way to gain a little more fuller sound (and more volume, if desired) while pushing the horn and bell localization forward.
 
If you want to maximize the depth of sound in these units, I offer the following alternative that requires a simple modification:
 
Remove the rear weight, which is held in place with a single screw. You can then simply cut-off the stock speaker-cavity and reinstall the rear portion of the weight. This cut is very easy to make with an inexpensive hack-saw and about 60 seconds of work. This makes room to install the RAPO-40CM-RC1 system. This will provide a MUCH bigger, beefier sound with greatly improved bass. You can still add one of the front-mounted companion speakers to improve horn and bell localization and gain more volume.
 
The speakers come fully assembled and tested.
 
Dimensions are:
 
AHGS-2800-RC1: 28mmDia x 14mmH
AHGS-2845-RC1: 12mmH x 17mmW x 26mmD
AHGS-2860-RC1:12mmH x 18mmW x 18mmD
 
VIDEO: https://youtu.be/Q258gpHuoLw
VIDEO: https://youtu.be/dg2n71FN8wU