Emu XL-7 & MP-7 User's Group

Well Emu can certainly defend themselves, but it may be helpful 
to understand that the filters Emu uses were(are?) quite 
innovative for digital filters, though when compared against 
today's world of VA type filters they seem inadequate.  What Emu 
"invented" with the Morpheus concept was the ability to make a 
filter that could be changed from one type to another in real-time.  
So you could have some pretty twisted filtering characteristics, 
far beyond the tradition sweep the cutoff frequency limitation.

But this approach to filter implimentation has a limit in that only 
one parameter can be varied in realtime.  Now this parameter 
can cause quite complex things, including changing multiple 
traditional filter parameters - things like sweepin frequency while 
changing bnandwidth.  But you only get to "morph" in one 
dimension at a time.  So a tradition synth filter, like a 4 pole 
lowpass can have real time adjust of cutoff but not resonance.

The work around is that in an instrument like the P2K 
architecture, since it supports truly dynamic voice allocation and 
is multitimbral, you can switch filter types on the fly from note to 
note.  So to change Q is really replacing one filter with a slight 
variation with the Q increased or decreased.  This is why 
resonance is usually a note-time only adjustment.  I do seem to 
recall at some point either my Audity 2K or Ultra having a filter 
where Q was not fixed at note time, but I could be mistaken.

BTW, the above explaination is what I have sussed out of the 
Emu information and products I have owned over the years.  So it 
could be incorrect, especially in the details.  But this is my 
understanding of why the filters are as they are.

Should Emu change this?  That's another question entirely.  Its a 
tradeoff really.  Is it better to have a few traditional filters that 
behave "normal", or to have the flexibility of filter types.  Also, Emu 
has quite a few morphing filters in their archives.  They could 
well add new ones to the XL7/MP7.

Which leads me to a question: why isn't the famous "BatPhaser" 
filter in the XL7/MP7?

drK