Okay people another stupid question from me that doesn't have a real answer. What is the best sound decoder for diesel locomotives in general.
Soundtraxx Tsunami, either standard series with JST 9 pin, or Micro-Tsunami.
Many models available, depending on the "prime mover" of your locomotive. (EMD or GE and others, and their various "generations".)
I installed a 3rd Gen in an AC4400, sounds great.
There is no Best sound decoder. There is what works Best for you. There are many variations on how decoders and speakers are installed. Many times the decoders need programming for what sounds Best to you or more prototypical. If you are not a rivet counter, then generic sound should be ok.
Here is an example of how you can search the 'Net for possible answers.
http://www.google.com/search?hl=en&ned=us&q=dcc+sound+decoders&btnmeta%3Dsearch%3Dsearch=Search+the+Web
Compare info from different people. Some people use a sound Only decoder along with the decoder that controls everything else. It can be a complex subject.
Rich
In general, the best sound decoder for a diesel locomotive is a medium steam. :D
Gene