Check out this site!

[aron]

Of interest is the active filters section and microphones!

My friend turned me on to this site.
//http://www.linkwitzlab.com/

[Nasse]

Thanx for link, tons of info and those nice filter circuits and more. And I am sure that for us guitar effect guys it is easier to understand and even hear what unwanted "phase shift" can cause for your P.A, hifi or multi-way speaker system.  :wink:

[Nasse]