MDDS30 Motor Driver PWM Mode

[gerald5]

Hi,
can anyone help me adjust and set up this motor driver in pwm mode as I have two
motors, one which is slightly faster than the other. both are same specifications.
left channel for left motor. right channel for right motor. this is on an tracked flail
mower and I've just replaced one motor and strangely is slighty slower on full stick!
smart drive duo-30. basically I plan removing the non adjustable controller
presently installed.
the manual is quite confusing and I'm not familer with motor controllers.
any help would amazing
Thanks