Kevin,

The MRC 1639 includes the speaker.

Hunt, 

Thanks for your candid information.  After reading the EZ-Commader manual on-line, your first response was on target as well as your most recent assessment.  The Steam Digital Commader will be a Chirstmas present for my eight year old grandson and a starter set as well.  As a youngster I always wanted an on board steam whistle for my American Flyer Peacemaker steam engine.  This is whats driving my search for a sound decoder that will work with the Steam Digital Commander.  I understand the points you made but I am trying to keep this first train within reasonable cost. I found the MCR 1639 on-line for $49 and per its instruction manual, F-1 thru F-8 on the EZ Commder should operate the basic sounds without changing any CVs.  Sound quality may be less than what a dedicated model train hobbyist would find acceptable, but  for my situation it will hopefully prove adequate.  My biggest concern is that the 1639 will turn out to be substandard in all other aspects compared the decoder which comes with the Steam Digital Commander.

One again thanks for the responses, they have been extremely helpful in my evaluation and decision process.

Will the sound decoder #1639 from MRC work with the Steam Digital  Commander by Bachmann?