Agreed with h3; Ravenswood and Lincoln Square are two very different neighborhoods (unless the tour is actually of the Lincoln Square community area?).
Sorry, I just had a hankering for a good old-fashioned knock-down, drag-out, Chicago-style neighborhood boundary debate-- well handled :-)
I came across an old old book on Lincoln Square somewhere not too long ago . . . if I didn't know better I'd have thought it was one of those neighborhood names that realtors or the local CoC came up with in the 70s to try to move some real estate. I lived in Lincoln Square around '95 for a little over a year.
Are you planning on having a group size limit? Just thinking of the Hyde Park one we just did. If you used your bike-mounted PA system during that ride, I don't think many of us were able to hear you, at least I was not able to -- only at the stop/break sites was that possible. Still a fun ride regardless. :)
Yeah. It was a Hyde Park critical mass in a way. That was neat to see. As far as your plans for sound, does that mean that you could talk from way in the front and we would have speakers in the middle and rear of the pack from which we could hear you? If I've interpreted that correctly, that would be cool -- real-time narration in motion.
Hmmmm... maybe if someone handy with electronics could wire short-distance / low-power receiving walkie-talkies to relatively low-power (but still powerful enough) amp/speakers, maybe even bullhorns. Two to four sets of that with you talking into the transmitting handset might do the trick. Distributed power requirements that way. Perhaps more common and less $$ components. Have a flexible strap/bungie/whatever mounting system that would allow you to mount it to any riders who show up with racks on their bikes and have them ride evenly spaced out in the group. Possible?