I was wondering how hard would it be to add sound to the Bachmann Digital Commander Deluxe Set HO here is the info listed
Santa Fe GP40 (#3507) and FT-A diesel locomotives are all-wheel
drive & DCC-equipped with 28/128 speed step decoders that are
factory-programmed to address button 3 on NMRA-compliant
DCC systems.
it would be pretty difficult for a beginner, requiring a complete disassembly of the locomotive, and milling tof the chassis to provide a space for a speaker. it can be done, but it is easy to mess it up. it would be much easier to add sound to a steam locomotive, as the tender is usually empty and provides plenty of space for a speaker.
a better option might be to find one of the sound value engines on sale on ebay at a good price. any dcc locomotive should work with your controller.
Thanks for the reply It saved me some problems.