Adjust CV2 for start. You need to take the worst case one - the one that starts the fastest, and match the others to it. Then adjust CV5 for top speed. Since you are limiting the top speed to well under what th eloco can do, just adjust CV5 until they all run the same speed at full throttle. Finally, adjust CV6 for mid speed, at half throttle, so they all run close to the same speed. They should now all be the same across the throttle range. it doesn;t matter that it appears that there are not 28 steps between start and max - whatever the speed range between those CVs will be broken into 28 steps. 30, for example, in CV5 does not mean step 30. It means 30/255 of full power. There is also a step by step tuning guide in the Digitrax Tech Support Depot (also in the Digitrax Decoder manual - the full manual, not the leaflet that comes with the decoder) which you might want to check out, you may be able to get the start speed down by adjusting the motor control parameters. Since you run at slower speeds, the slower you can get the locos to start the better it will be. AFter you have each loco adjusted as well as can be, then start messing around with CV2 to get them to all start at about the same speed.
They just have to be close - slight differences will easily even themselves out with the load of a train.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
I am running Athearn Genesis locomotives equiped with either Digitrax 126 or 166 non sound decoders. Most of my start voltages are set around 10, with top voltages set in the low 30 range, as I have a small layout and anything over 40 seems to fly around the tracks. So, as I work on speed matching, I am just a bit baffled on how I sound match the settings, as I dont have 28 spots between start and top speeds. Should I set my top speed higher and only run up to say a "5", ignoring the top 23 speed steps? Set the mid speed for something like 15? Curious how you are setting this up. Would also be curious how you are speed matching "stock" Athearn sound locos with digitrax equiped non sound locos as the start and top voltages for the same speed are so different, or should I quit the digitrax non sound decoders and go to something else? Thanks for your help.