Bandpass filter design

[jbushnel]

I was going to order this kit from jameco but I had some questions about the filtering!

http://makezineblog.files.wordpress.com/2010/10/ledcolororgan-schem_r2.gif

I wanted to pretty much keep everything the same but I wanted to change where the bandpass occurs (and maybe slightly change the bandwidth). I noticed that the only thing that changes for each filters are the three capacitor values. How would I go about choosing the values for the filter components? I have done an "online filter calculator" but all of the values are not as rounded as the one in this schematic...

To me, they look like third order filters: The first two stages is an active filter where there is multiple feedback. Then the third stage is the passive high pass filter that is connected to the output of the op amp. I don't know how to go about fitting it for my need. Thanks!

[T3sl4co1l]

If you keep the resistor values constant and vary the capacitors in proportion, the break frequency will vary in direct proportion as well.  As such, you can round the values to the nearest common value to get something pretty close.

Tim