Here is a proper tutorial I found online about mixing a kick drum with a bassline or any other instruments. This guy that gives you the basic knowledge on how to mix a kick drum with a bassline. You don't need the VOXENGO SPAN (free plugin). As long as the EQ you use has an analyzer it will work. The new Ableton live 9 EQ8 does the job easy as wel as an other plugin i like the use FABFILTER PRO-Q