Either a wide pattern mic at an intermediate location (which I'm willing to try in my bedroom as an experiment, but I predict would not work anywhere near as well for a recorder as it does for a guitar[*]) or a cardioid/hypercardiod mic at a farther distance (more likely to get the sound right in a studio) would be asking for trouble on stage. Unless the acoustics of the hall are very good, the farther you get from close-mic techniques, the more you risk feedback -- and we (http://www.wam.umd.edu/~eowyn/3LF/index.html) usually play outdoors or in banquet halls and gymnasia, not theatres. Also, the farther away or the wider the pickup pattern, the more bleed you'll get from other instruments -- not a problem if you're trying to area-mic the whole band, but a big problem if you're trying to use the PA to boost a soft instrument against louder ones.
I haven't gotten this far in my experiments yet, but what I've read suggests that the foot mic really ought to be farther away[**] than is likely to be feasible in a concert setting, so even using two mics per recorder on stage is still probably going to involve compromises.
On stage, especially at a festival where you're at the mercy of somebody else's equipment, you may have to worry about the number of channels and microphones and stands available, as well as the strictly acoustic issues. An attached mic rig, if it doesn't make the instrument unwieldy, removes stands and number-of-mics from the equation (because, presumably, the musician would own the dedicated mics and bring them along), and presents the possibility of pre-mixing the two mics so as to still only use a single channel at the sound board. But both mics will still probably be closer than they should be for optimal tone (though this will improve the feedback situation!).
But for recording, whoa, tone really, really matters. And even if someone can't do it perfectly, there's a lot to be said for Not Doing It Wrong. The difference between a single close-mic and the pair (or a room mic if the room supports it) is a big deal.
[*] There are a bunch of ways to record a guitar. For the second (http://cdbaby.com/cd/homespunceilidh2) Homespun Ceilidh Band (http://www.homespunceilidh.com) album, my guitar was recorded with, I think, four or five mics at once (off the top of my head I recall: a large-diaphragm room mic several feet away, and neck and body close mics, with a stereo pair being involved somewhere (body?), and a fuzzy recollection of a fifth mic somewhere). But using just two close mics is pretty common for guitar (and on stage (at least) you can get away with a single mic positioned just right). On stage, I use a coil pickup in the 6-string and a clip-on condenser mic on the 12-string. If I were doing "sit on a stool and play impressively delicate stuff", I'd want two guitar mics on booms; but when I play guitar on stage I'm mostly doing the "jump around and make a whole lot of crunchy chords playing high-energy music with eight other people" thing, so attached pickups that get the basic tone[***] are an appropriate solution until I get into the studio. I see a similar set of choices WRT recorders on stage: the ideal audiophile solution might not fit the compromises of live sound in a festival setting.
[**] Similarly, a violin really sounds best at a distance farther than you want to put a mic in any situation where feedback or background noise (including bleed from other instruments) are issues.
[***] I'm still picky enough that not just any transducers will do.
For something like a recorder, I would be thinking in terms of a small mic stand on the floor with a cardioid pattern mic pointing upward. Then I would probably use a small boom to place another cardioid mic near the recorder's window. If you move around a lot, jumping, etc. not swaying in a chair, then you are almost required to look at that mics attached to the instrument's body.
The mics don't have to identical, remember that you are picking up two different types of sound. Also, the slight phase differences that you saw are important. When I mic hand drums (congas, whatever...) I have been known to hang a condenser pointing down at the drum heads and place something like an SM57 under & pointing up. That way, I get the hand slaps, and the first sound from the heads, and the very slightly out of phase beefier sound from the drum body.
Something that you might think about for your gear for PA use & recording is to get a small 4 to 8 channel "sub-mixer" and put together a small mic snake with your mics, etc. That way, you can quickly mute & unmute various instruments, and feed one consistent signal to the house mixer (something sound guys like :) ).
When a) the hall is really good to begin with, b) the amplification is subtle, c) there are no monitors, and d) the sound is "pre-balanced" perfectly by the performers, then you have an exception to the "Wide pattern mics on stage... bad" rule. But since most of aren't micing symphony orchestras in the Meyerhoff or choirs in someplace similar, I'm only noting the exception for the sake of completeness. For pretty much everything else (okay, there are some applications for area mics in theatre as well, but ...) yeah, the rule is "don't use wide pattern mics on stage," maybe with some exclamation points.
I want identical mics specifically for the purpose of comparing the two sounds in tests like this. I agree that they don't have to be (and possibly shouldn't be) identical in actual use as opposed to "the lab". Though if I were to try to build a dual-attached-mic rig, I'd probably wind up using identical or nearly identical mics anyhow: tiny cardioid condensers -- lavalier or mini-gooseneck style -- for weight reasons.
The info about how you mic your drum (and why) is a great example here. Thanks!
I was thinking about just a two-channel, belt-mounted mixer for attached recorder mics, though if that winds up being expensive or needs to be custom-built, then yah, it'd be easier to build a custom two-channel snake to a small stage mixer. (Hmm. Just how bad an idea would it be to convert the mic signals to unbalanced so they can share a single standard XLR cable for the short distance from the instrument to the stage submixer?)
But I've definitely thought about submixers before, either a drum mixer ifwhen I ever need to mic my drum kit, or just a "tie up fewer channels at the console with all the instruments I use" mixer.
Re: Miking recorders
I haven't gotten this far in my experiments yet, but what I've read suggests that the foot mic really ought to be farther away[**] than is likely to be feasible in a concert setting, so even using two mics per recorder on stage is still probably going to involve compromises.
On stage, especially at a festival where you're at the mercy of somebody else's equipment, you may have to worry about the number of channels and microphones and stands available, as well as the strictly acoustic issues. An attached mic rig, if it doesn't make the instrument unwieldy, removes stands and number-of-mics from the equation (because, presumably, the musician would own the dedicated mics and bring them along), and presents the possibility of pre-mixing the two mics so as to still only use a single channel at the sound board. But both mics will still probably be closer than they should be for optimal tone (though this will improve the feedback situation!).
But for recording, whoa, tone really, really matters. And even if someone can't do it perfectly, there's a lot to be said for Not Doing It Wrong. The difference between a single close-mic and the pair (or a room mic if the room supports it) is a big deal.
[*] There are a bunch of ways to record a guitar. For the second (http://cdbaby.com/cd/homespunceilidh2) Homespun Ceilidh Band (http://www.homespunceilidh.com) album, my guitar was recorded with, I think, four or five mics at once (off the top of my head I recall: a large-diaphragm room mic several feet away, and neck and body close mics, with a stereo pair being involved somewhere (body?), and a fuzzy recollection of a fifth mic somewhere). But using just two close mics is pretty common for guitar (and on stage (at least) you can get away with a single mic positioned just right). On stage, I use a coil pickup in the 6-string and a clip-on condenser mic on the 12-string. If I were doing "sit on a stool and play impressively delicate stuff", I'd want two guitar mics on booms; but when I play guitar on stage I'm mostly doing the "jump around and make a whole lot of crunchy chords playing high-energy music with eight other people" thing, so attached pickups that get the basic tone[***] are an appropriate solution until I get into the studio. I see a similar set of choices WRT recorders on stage: the ideal audiophile solution might not fit the compromises of live sound in a festival setting.
[**] Similarly, a violin really sounds best at a distance farther than you want to put a mic in any situation where feedback or background noise (including bleed from other instruments) are issues.
[***] I'm still picky enough that not just any transducers will do.
Re: Miking recorders
For something like a recorder, I would be thinking in terms of a small mic stand on the floor with a cardioid pattern mic pointing upward. Then I would probably use a small boom to place another cardioid mic near the recorder's window. If you move around a lot, jumping, etc. not swaying in a chair, then you are almost required to look at that mics attached to the instrument's body.
The mics don't have to identical, remember that you are picking up two different types of sound. Also, the slight phase differences that you saw are important. When I mic hand drums (congas, whatever...) I have been known to hang a condenser pointing down at the drum heads and place something like an SM57 under & pointing up. That way, I get the hand slaps, and the first sound from the heads, and the very slightly out of phase beefier sound from the drum body.
Something that you might think about for your gear for PA use & recording is to get a small 4 to 8 channel "sub-mixer" and put together a small mic snake with your mics, etc. That way, you can quickly mute & unmute various instruments, and feed one consistent signal to the house mixer (something sound guys like :) ).
Janice
Re: Miking recorders
I want identical mics specifically for the purpose of comparing the two sounds in tests like this. I agree that they don't have to be (and possibly shouldn't be) identical in actual use as opposed to "the lab". Though if I were to try to build a dual-attached-mic rig, I'd probably wind up using identical or nearly identical mics anyhow: tiny cardioid condensers -- lavalier or mini-gooseneck style -- for weight reasons.
The info about how you mic your drum (and why) is a great example here. Thanks!
I was thinking about just a two-channel, belt-mounted mixer for attached recorder mics, though if that winds up being expensive or needs to be custom-built, then yah, it'd be easier to build a custom two-channel snake to a small stage mixer. (Hmm. Just how bad an idea would it be to convert the mic signals to unbalanced so they can share a single standard XLR cable for the short distance from the instrument to the stage submixer?)
But I've definitely thought about submixers before, either a drum mixer ifwhen I ever need to mic my drum kit, or just a "tie up fewer channels at the console with all the instruments I use" mixer.