This is a Rectify Series drop-in speaker system for Athearn Genesis F-Units that have the early, pre-sound frame (no cavity for a speaker in the rear). More than just a box, the enclosure features Diapasonic Tuning™, which allows the lower frequencies to accurately develop and resonate, clears the midrange of excess resonance and tunes the upper-mid/high response. Carpet tape or a touch of adhesive secures the system. No modifications are needed.
 
If you're using a short motherboard such as the Nix Trainz Decoder Buddy, or installing a hard-wired decoder, there is room to add the front-mounted AHGS-ACAB-RC1 speaker. If using a PCB-style decoder such as a PNP or Direct, there will not be room for the ACAB speaker.
 
The speaker comes fully assembled and tested.
 
Dimensions:
AHGS-F700: 13mmH x 28mmW x 42mmL
AHGS-ACAB: 12.5mmH x 25mmW x 11mmL