aftertouch - poly, channel???

hy 4k headz

any aftertouch expert in here willing to help?

i m not sure whether i understood it correctly ... in program mode - misc page - there are those settings for aftertouch! i got doubts on type: channel or poly, and i asume channel stands for ch. pressure messages and poly stands for poly pressure messages - question: is that correct and if so can someone please tell me the difference between channel and poly?

currently i m testing and guessing (... and checking the manual which doesn't say much about it) ... and i asume that channel and poly is quite the same - meaning i asume that the only difference is that some gear is sending channel whilst others are sending poly prssure messages? is that correct?

coz if i use aftertouch on the 4k (set it on prog mod window to some destination) only poly seems to work, whilst there isn't happening anything if i set it to channel.

so next questions: am i rigth in asuming that the 4k pads are just sending poly pressure messages? can i send channel pressure messages from the 4k? or do i need an external midi keyboard for that? whilst channel is implemented on the 4k only to allow aftertouch with external gear?

does that all make sense or am i totally wrong? ... as i said ... i m just asuming and guessing - so i hope not to confuse anyone and hope that someone could clear that ... any help is greatly appreciated ...

channel aftertouch operates on midi channel level and therefor has effect on all notes, even when you press just one into aftertouch. If you press more than one the highest value wins.

poly aftertouch only effects the note you press. When you press more notes at the same time, each note has it's own individual pressure amount.

Most midi keyboards and synth modules use channel aftertouch. Only some understand poly pressure.

hi,

I'd like to buy a MIDI Keyboard to plug in my 4000 and to play bass notes, piano multisamples,...

does anybody know if the M-Audio Keystation 61es ( http://www.m-audio.com/index.php?do=pro ... cale=en_us ) can do that ?


thanx

hy bleepfreak thanx alot for your help ... always explaining complicated things easy ... much appreciated ... the difference between poly and channel is now clear ... but i still got a question: is it possible to transmit channel pressure messages from the 4k's pads? if so how?

let me explain ... i use the 4k with the virus kb ... it might get confusing - as i am - but the question remains still the one above ... how to send channel pressure mess. from the 4k's pads

1) aftertouch on the 4k's sampler: if i use the 4k's pads to use aftertouch on the 4k i get it to work only if i set it to poly whilst if i set it to channel i don't get it to work.

on the other hand if i use the virus keyboard to use the 4k's sampler aftertouch i have to set it to channel and it worx, if i set it to poly not ...

2) aftertouch on the kb: i only get it to work from the virus keyboard (i have to set it to channel pressure) ... i don't get it to work from the 4k's pads at all atm (in order to do so i would probably just need to send channel pressure messages from the 4k)

i checked in midi mode on the 4k which data gets sended from the pads and which from the kb keyboard: the 4k displays in midi mode when played from the pads 'key press' (i guess that stands for poly), whilst from the virus keyboard its called 'pressure' (i guess that stands for channel) - besides that the kb allows me to set the midi parameter high page to PolyPrs but that doesn't change anything the 4k still displays it as 'pressure' and it affects aftertouch on both the virus and the 4k the same ...

i also checked the sysex implementation chart for both the 4k sequencer and the kb - it says the 4k sequencer transmits and recognizes aftertouch key's (dunno but guess that stands for poly?) and ch (guess that stands for channel?) - the kb according its implementation chart is not able to transmit anything neither key's nor ch's, doesn't recognize key's but recognizes ch's.

long story short sense - i m confused - and somewhere there is a mistake - either in the implementation charts or in my mind ... coz against my expectations the kb keyboard is able to trigger the 4k's aftertouch if that is set to channel - which is great (and against my expectations coz i asumed it ain't able to transmit anything).

on the other hand (back to the initial question) it would be great if i were able to trigger the kb's aftertouch with the 4k's pads, and besides that it would be nice if i were able to use channel aftertouch on the 4k when played from the pads aswell - but for both i would need to send channel pressure messages from the pads which i don't know how to do (and according midi implementation chart should be possible) ... if anyone could tell me how to do that it would be greatly appreciated ...

mistery ... only thing i know is that the 4k's aftertouch either worx if ya send it channel or poly pressure data ... what you could do is searching a manual for that keyboard - have a look at its midi implementation chart and check what it says bout transmitting aftertouch data ... curretnly i m having doubts myself regarding the midi implementation charts of my kb and 4k aftertouch info so i ain't really the right person to answer your question - maybe i can answer more precisely once i've sorted things out here

okay

thank you and good luck