Mike Remus,

Awhile back I tried to disagree with a tip you offered here about taping a microphone to a speaker for an audio feed. The idea just didn't sound good to me (pun intended). The more I tried to disagree the more I realized I was wrong. Recently I was at an event where I was unable to get a feed from the board, so what do you think I did? I laughed to myself, chewed some crow, and got out my trusty gaff tape. I dug out an old SM58, with a dented screen (no doubt I have used it for a hammer even though I still deny it) and taped it to an EV200. An instant program feed was achieved. Thanks for the tip!

Steve

Shure thing

I, too, have tried this on one occasion and was able to
add a fullness to the final mix with what I got this way.
I placed the mic on a 6" mic stand and set it atop
the speaker. My main problem was that the dynamic I
used was peaked toward higher frequencies, being
primarily designed for vocals, not music.
I've been thinking about the AKG D770 handheld
because it's also designed for mic'ing instuments.
Wondering if this might give me more balance in the
music, not so much emphasizing the highs.
Anyone have any experience with the D770?

I have a couple of them. They have a very rapid fall-off to their proximity effect. While all directional mics do this to some extent, the 770 are noticeably bass-lite after only 8". I think they do this so you can make larger changes in sound while keeping the mic within a reasonable distance of the instrument(?).
If you can still find the non-modular versions of the D880 for their $50 clearance price, I find them more versatile. They have a tighter pattern (sometimes good/sometimes bad) but I feel they have a more even sound overall at a variety of distances while still giving good proximity when used close up.

That's good to know, Jay, because I believe it's the proximity
effect that I'm looking for. See, the sound from the
cam's on-board mic sounds hollow and I want to
supplement it in post to give it more presence.
Should I take a look at any of the Shures, or am I
just as well off going with the D880?

I think the SM57 has a less pronounced proximity drop off than the D770, so that would probably do the trick.
In addition to micing a loudspeaker, what would be a more likely secondary use of this mic? If you say electric guitar amps or snare drum, then go with an SM57. If you'd like to have a very good dynamic vocal mic, get the D880. The D880 probably has better internal shockmounting. That would be another plus for it.
I haven't used the new modular version of the D880, it has an M added to the name. It's more expensive than the original and the second versions, which are still around if you look.