I've been interested in the Niveau filter for quite some time, now. I was *this* close to buying the ADT version, but I decided to postpone it and put the cash elsewhere.
Say, anchor point of 700-800Hz. +/-3dB max. I have no idea how does the classic "tilt EQ" circuit sound like:
http://gilmore2.chem.northwestern.edu/projects/showfile.php?file=equal_prj.htm Could be something to consider.
Parametric bands? I'd try Dove's CAPS filters, because I haven't tried them yet. I haven't tried Wein bridges either, but CAPS interests me more.
Paul has a point with LPF/HPF. I've began to use LPF's now and then. I'd make them 2nd order, Sallen-Key filters and Q=0,57.