MOTM

> So, why is it that (performance) synthesizers have traditionally only 
> had one measly filter?  

Because it isn't needed for the vast majority of applications of 
(performance) synthesizers--applications which are not imitative 
synthesis. Since it was/is quite difficult to do imitative synthesis 
with the analog instruments affordable by most keyboard players (i.e., 
the minimoog and its close relatives) most people didn't use them for 
imitative synthesis. Then digital sampling came along and for the vast 
majority of applications that did/do require imitation of acoustic 
instruments, digital technology proved to be far more cost-effective 
and easier to use. 

> Why essentially no eq at all? 

More or less the same reason. Also, if you really need(ed) an EQ on 
your synth, there were/are any number of outboard EQs available.

> I think 
> there's a real opportunity here for a clever new module that allows 
> severe (big boost/cut) and detailed (many frequencies) EQ capability. 

Just out of curiosity, how many frequencies is "many"?

On a vaguely related note, my understanding is that the MOTM-450 filter 
bank never went into production because of a definite lack of interest 
from the buying public, so the "real opportunity" may not be as large 
as one might think.

--Adam
DISCLAIMER/DISCLOSURE: my company sells a filter-bank plug-in, so yes, 
I may have a commercial interest in this thread.