There is so much information, articles, books, and free software available via a quick search on the web, that you should be able to find what you need in minutes. Many student textbooks go through the maths in great detail. The equations as presented are not much help in obtaining component values, since a number of steps need be gone through, and with the higher order filters, it becomes highly impractical. Not so many years ago, filter design was based on voluminous tables, which together with a calculator, simplified the process. Now there is a ton of free software to do the work. For a look at how a filter is tackled from first principles, http://www.ivt.ntnu.no/imt/courses/tmr7/resou...001-Design_and_Analysis_of_Analog_Filters.pdf http://d1.amobbs.com/bbs_upload782111/files_26/ourdev_534477.pdf https://www.youtube.com/watch?v=3yyp5JRqNXs
