Athearn sells a Genesis GP15-1 with SoundTrax Tsunami installed, so something fits in for sure. Assuming you don't want to swap the unit with a sound one, you could just call Athearn and ask what model they used of speaker, baffle and decoder.
Tsunami installations are not that heard, but IIRC the quick plug won't take a stock Tsunami. You would need to swap the board out but should not involve separating motor leads etc as the board will bring all the wires you need. You likely won't also need to do any cutting of metal.
Good luck!
The first thing you need to do is look at the exploded diagram that came with the loco and see if there is provision for a speaker, because even though it's "DCC Ready" with a quick plug does not mean there is room for a speaker.
Soundtraxx or Locsound. I have an Athearn SW1500 I put sound into. I took out the PC board and installed a board type decoder. I like this better than trying to fita plug in decoder. Joe
I am new to the dcc world of model railroading, and I was just wondering what the best kind of sound decoder would be for a Athearn Genesis ho gp15-1. I just got a Digitrax Zephyr dcc system and i haven't yet put any decoders into my engines. It has the quick connect . Any help with this would be greatly appreciated.