thanks for the info! it works and it's great!
what i did:
1. enable the IAC bus in the audio/midi setup
2. insert a channel splitter after the physical input in the Logic environment, connect channels 1 through 8
3. create a new multi instrument in the Logic environment, enable channels 9 through 16
4. select the multi instr (i named it pd) on a logic midi track
5. notein in PD (fed into one of my funny little synths in my case
6. create aggregate device in audio/midi setup: soundcard or built in + soundflower (to be found at cycling'74)
7. set sound comm to the aggr device in PD's preferences and Logic's preferences
8. select the right ports as the input for a logic audio track

works like a dream. been having a lot of fun replacing the out-of-the-box strings i used for a filmmusic project by some pd synths. hope to gain some more understanding of building synths and using what's already there (rrad, plugins) (any final decision on including plugins in the distro yet? i may have missed it, haven't been following the list too closely lately).

robbert