On Mon, 11 Feb 2002, Brousseau, Paul E (Paul) wrote:
> Not to proove just how dense I am, but how does this make sence? If you
> input a tone with freq. content from 80Hz to 800Hz, and set the HP to
> 100Hz and the LP to 400Hz, then the BP out should give you 100-800Hz and
> the LP out should give you 100-400Hz.
>
> One of us hasn't had enough coffee, and it's probably me. Help?
It is the jack labeling that is confusing everyone. Perhaps Paul can
have the outputs labeled 'BP1' (for BP output of 1st filter) and
'HP1->LP2' (for first filter HP output chained 2nd filter from which is
taken the LP output. This is how the CS filters are configured).
Note: if one is just using the BP output, then the 2nd filter's controls
(FREQ LP, RES LP) aren't going to affect anything. The "super-bandpass
filter" that Paul describes only happens when using the LP output and
adjusting both filter sections accordingly.
Crow
/∗∗/