Trying to Understand the TI's Series / Parallel Filters In a Practical Manner.

    hey all,


    Im on the learning curve with synthesis and have been a owner of TI2 Desktop for only a few weeks. (my first hardware synth).
    Im here now trying to gain better knowledge on the TI's Filter and how it relates in a practical manner to sound design.


    I will start with the Filter / Series configuartion:
    So my first question is:


    (Q1) By having the same Cutoff value on both filters does it turn into a 4 Pole Slope Filter ? or is it just a re-inforced 2 Pole ?
    (Q2) When the Cutoffs are "Linked" whats the point then of having a different cutoff value for both filters ?
    (Q3) Whats the point of "UN-linking" the cutoff between the filters ?
    (Q4) In regards to sound design what is the purpose of "Offset Filters" , would this only be useful to do things like create your own bandpass or bandstops ? or is there more to it then that ?


    My guess answers are:


    (A1) Re-inforce 2 Pole ?
    (A2) Having Cutoffs Linked and setting individual cutoff value's you can create your own bandpass / bandstop filter ?
    (A3) The point of un-linking the cutoff is so it reduces to a 2 Pole sweeping through ? (less filtered sound ?)
    (A4) Having a "un-linked" cutoff and offset filters you have individual control over both filter cutoffs , i don't understand what this is useful for , is it useful for more custom modulation options ? or other reasons aswell ?



    I would like to know what other people do with cutoff linking / unlinking and offsetting filters etc ?


    any input would be greatly appreciated
    thanks :)

    a1)
    It all depends; I suppose you're routing the filters in series, if the 2 filters are identical 2 pole filters you will be having a 4 pole filter, but if the filters are different things may change.
    I could tell you a lot about this, but I believe there is a filter tutorial on the Access Website that explains this bits very thoroughly
    a2)
    well... there is quite a point; if you are using a lowpass and a highpass in series, or using some other parallel or split configuration, being able to move both filter frequencies with a knob while another knob controls the offset of the two can really create interesting effects, you also have the added advantage, if you put a bit of resonance of being able to generata two independent resonant peaks
    a3)
    well, maybe you want to control or modulate the two separately; it does make plenty of sense really, on the virus, having that much polytimbrality it isn't that essential, but it is quite a trick for creating complex evolving sounds on one single layer, typically again, not using the two filters in series. The split mode for the filters for example can be used so that filter two (which receives osc2,osc3 and the noise generator) processes some noise being modulated by an LFO that makes it somehow percussive, while osc1 and the sub get processed by filter 1, and can be anything, a Bass, a pad...
    You got quite a machine to start from... I just recently got a virus after 10 years of other VAs and well... why didn't I get one sooner?

    thanks for the reply ohmsweetohm, I appreciate it.


    Would you happen to have the Filter Tutorial link to share ?


    I recently bought myself a FFT analyser so ill get hands on and hopefully I can gain a visual idea of whats happening with the filters and learn from that too. Im sure its not so difficult , im just new to the 2 x filters.


    You got messenger or anything ? would you be interested in getting in touch ? sounds like your experienced in the field and I would love to talk technical chit chat.


    take it easy
    thanks