In general, the Rhodes are very bassy, it sounds more like an EQ issue rather than voicing from your description, however the timbre adjustment could be off also.
What a Rhodes should sound like is somewhat subjective, it depends on you and your ears. Some people like the crisp bell like tone, I personally prefer the darker, less trebly tone.
Making a consistent tone and volume from key to key is what voicing is about, but the way you set your timbre will vary from person to person based on preference. ( you set timbre by changing the angle of the tine tip in relation to the pickup)
See figure 4-8 in Rob's link above.
You change volume by moving the pickup closer or farther away from the tine.
Make sure your escapement is set properly first.