Use the knobs to balance them. Use the Keyboard tab (bottom) to set key ranges:
Before we dive into the nitty-gritty of Sylenth1, let's cover the basics. Sylenth1 is a software plugin that can be used in a variety of digital audio workstations (DAWs) such as Ableton Live, FL Studio, and Logic Pro. Once you've installed Sylenth1, you can load it into your DAW as a plugin.