LXH2 questions

[Connoisseur of Distortion]

It says that a dual power supply is needed, and i do not see why. All i see is a need for a V+ and a ground... Can anyone explain why? my only guess is the the Vcc+ and Vcc- are used as rails so that biasing to V/2 is not necessary... am i right here?

I do not have a 100k dual ganged pot. I do, however, have a 50k dual ganged pot. I know that since this is a voltage divider, it will function, but I want to know if the easier path to ground will sacrifice my tone. Comments?

On the speaker simulator, i see that multiple filters are placed in parallel with varying degrees of output to get the response of the cabinet. My confusion stems from the idea of using peaks and dips, and with only changes in part values to do this. I believe that it is making band passes and stops, so they can overlap by focusing or excluding the range of frequencies. I am just making sure that no change of the 'fill-in-the-blanks' schemo is necessary.

Thanks in advance, guys... I think i might just have to build one of these