Well, *with* a genuine peak,
I thought maybe you meant that a genuine peak was a bp with such a
high Q that you couldn't see that flat top without zooming in and
therefore couldn't find the corners.
the corners are, IIRC the -3db points
either side.
No. The corners are the estimates of those points. They're found by
drawing lines along the passband skirts that approximates a
constant straight line rolloff and another line along the top of
the passband. The intersections are the corners. The steeper the
skirts, the more closely the corners approximate the -3dB freqs AKA
cutoff freqs.
Without a peak? What, you mean like as in the type of
'double-hunched' response you typically get with overcoupling two
tuned circuits? Yes, that's trickier. Hell, whatever, by all means let
the OP have *your* definition, Mike. *I* might learn something as
well. God knows I can use it!
You were off to a good start. You at least drew a verbal picture.
You f'd me up with that "genuine" peak stuff. I thought you read
something somewhere that I just didn't run into myself. Plus I was
f'ing with you to test the aforementioned BS factor. So I threw out
the question, "WTF"?
I was going to get all masochistic and post some derivations of the
attenuation curve of simple filters and try to show where the
cutoff freqs are, but I don't think that'll help the OP at this
point.
One thing that might help, however is to explain this -3dB stuff.
-3dB bandwith - the bandwith of the filter from the lower to upper
frequency points where the response is 3dB below the level of the
passband response.
Furthermore one can define another bandwidth like say -40dB BW
which gives an indication of the steepness of the passband skirts.
