I pray every day I break even, Cause I can really use the money!
I started with nothing and still have most of it left!
Sound-equipped Bachmann Spectrum locomotives use a SoundTraxx Tsunami decoder, so that is the brand you need to use.
When you get the decoder, it will not have an NMRA 8-pin plug on it, but by carefully cutting away some of the shrink wrap you can remove the solder-in wiring harness and substitute a JST to NMRA short harness. By doing this, the only soldering necessary will be the two speaker terminals.