Which resistors directly affect the frequency range?

I am currently working on an audio equalizer, and this is a link to the basic schematic I am using. http://www.daycounter.com/Filters/StateVariableFilters/State-Variable-Filter-Design-Equations.phtml
If I am not mistaking, it would be the R1 and R2. I am also using Don Lancaster's book called the Active Filter Cookbook. I am confused on which equation I actually need to solve for the resistors using a certain frequency range. I am grateful for any help. Thank you.