In a message dated 3/2/02 3:30:49 PM Eastern Standard Time,
mbedtom@... writes:
Tom Farrand writes:
>>Specifically, what are typical characteristics of a fixed filter bank
section? I admit that I thought a FFB was merely an early graphic equalizer
but others seem to indicate they are not. How do FFBs sections differ from
a
conventional graphic equalizer section? What sort of "Q" do such filters
use? A Moog 907A employs 8 band controls with a low-pass and a highpass
section. Do the low/high-pass knobs adjust the cutoff frequency of the
filter networks or the processed/unprocessed mix?<<
An EQ adds peaks or notches at different frequencies to a sound. You
typically only get about 12db of cut or boost. A fixed filter bank has a
bunch of bandpass filters arranged in parallel. If they are all turned down
you get no sound. If you turn one band up, you only get sound filtered
through that band. As someone else mentioned, you can get much more extreme
changes to a sound with a filter bank because of this. And just as you can
arrange a number of bandpass filters in parallel, you can also include a
lowpass and highpass in there too to do the same thing.
>>What is a "super-saw"? If I were to see one on an oscilloscope, what would
I
see? Sound-wise, is there much similarity between a "super-saw" and
hard-sync (of saw-VCOs)?<<
It's something from the Roland JP-8000/8080 virtual analog synths. It sounds
like 7 buzzy sounding detuned sawtooth oscillators. There is control over
how much to detune them. I would imagine visually it looks like 7 detuned
sawtooths, but that is something I will have to look at some day. No, it
doesn't sound like hard-sync. It is good for helping one get a similar sound
to old string synthesizers such as those from Crumar or Arp.
-Elhardt