Best mic placement; where to get AC adapters

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We've had "To Hear Ourselves..." two months, and my wife, a flutist, agrees with many of its teaching techniques, some of which she has been using herself for years. She's just getting into greater use of the recorder during lessons. As per the book's advice, I got a SONY TC-D5M and two Beyerdynamic M260s. Already I've recorded two student flute recitals with piano. The sound quality is fine, the size is just right for setup in cramped recital halls, and it beats paying several hundred dollars for a recording engineer, who's no better than I am at guessing where the flute will saturate the levels. (Flutes are very unforgiving, especially unpredictable student flutes, whose tone and volume wanders all over the place). I'm still trying to figure out mic placement, though. Beyerdynamic doesn't say what angle the mics should be at. I intend to get the demonstration recording of stereo mic placement. I'm also having trouble finding the Sony AC adapter they specify (maybe a generic 6-volt will work?). I've owned NAD equipment for many years, so I agree with your criteria for electronics. I too wish NAD would reconsider its less expensive end of the line. Thanks for very good advice. Bob Brown

-- (robebrown@rcn.com), March 06, 2000

Answers

Regarding mike placement: For best stereo imaging with these mikes, get a "stereo bar," which is simply a convenient mount that holds the two mikes on a single mike stand while allowing you to change their spacing. Beyer makes one, as do other companies. They don't cost very much. Place the mikes so that, when seen from above, they're angling outwards from each other at an angle of about 110 degrees; and so that the heads of of mikes are about 7 inches apart. (This sounds weirdly specific, I know; but it does work!) Be sure that, when seen from the side, the mikes are aimed at precisely the same vertical angle and both aimed toward the instruments being recorded. Be sure also that the assembly is shock-mounted, either by having the whole mike stand on something compliant or by having separate shock mounts for each mike. (The latter is far easier.)

Regarding setting levels: As you note, flute is tough, like soprano. Set levels in rehearsal at the loudest point of the music. (Or what's *supposed* to be the loudest point.) Take this level several times, and notice how many dB (on the meter) the level is reduced when you change the setting of the level controls. Find the setting where the rehearsal level just hits the highest level you want on the tape (perhaps +3 on the meter with metal tape; you could go higher but you don't want to risk 'print-through'). Then *reduce* the level by about 6 dB--so that rehearsal level hits only about -3 on the meter in rehearsal. This will allow for the adrenalin change of inexperienced performers. Consider using the machine's built-in 'limiter' to protect against the occasional uncontrolled peak. Try it in a test recording first to see what effect it has on the sound. (I've never used it.) By the way, teaching the performers to know where the loudest parts are--and what the timings are--is good for them!

Regarding AC adapter, I'll post again when I hear from Sony. Do *not* just use a generic one, as some have polarity reversed from others.

Would love to hear from your flutist wife about how the musical techniques in the book are working for her.

Happy recording & practicing!

-- James Boyk (boyk@caltech.edu), March 06, 2000.


My previous response about setting levels was too complicated. What I should have said was to set the levels at the loudest part of the music so that the meter reads about 6 dB below the highest level you want to put on the tape. That allows for the fact that performers play louder in concert. Different people have different increases in performance. The biggest I've heard of was 15 dB! More usually, it's something between 3 and 6 dB. Given the difficulty of recording flute, and that the players are inexperienced, I would allow 6 dB.

The highest level you want on the tape depends to some degree on what you're going to do with the tape. If it will be copied quickly to some other medium, you can go a bit 'hotter', that is, higher in level; right up to what the tape can take. (You judge this by making short test recordings at various levels and listening in playback for when you get 'into the tape.') If the tape will sit around for five years accumulating 'print-through' (which lets the loud parts be heard in adjacent soft parts), then you want a much lower level. It's a matter of the tape you're using and of the type of music being recorded, and is too specific to each situation for me to give good advice. A bit of experimentation will soon show you the way to go.

I expect that the flutists are startled by the beauty of the cassettes you're making!

-- James Boyk (boyk@caltech.edu), March 06, 2000.


Maybe the third time will be lucky. I apologize for doing this in an iterative way.

Regarding recording level: The peak-indicating lights on the TC-D5M flash at +6 VU, I believe; that is, 6 dB over the 0 level. You should set levels so that *in the concert* they flash just occasionally and never stay lit. This means that during "level-setting" before the concert, they should probably never light up.

Mike setup: You can try the ORTF as I described it, or try NOS, which is similar but with the mike heads a foot apart and angled at 90 degrees. Or try anything in between these, but always symmetrical as seen from above; and always aimed at the same vertical angle as seen from the side.

AC adapter: Haven't heard from Sony yet, but I believe that any 6-volt adapter will work if (a) it's capable of delivering an ampere of current and (b) it has the correct polarity.

There!

-- James Boyk (boyk@caltech.edu), March 06, 2000.


Thanks for this detailed information. I do have a bar for the mics, on a portable Ultra mic stand, whose cross-bar mounts them 8" apart. Sony tells me that information about availability of their adapter can be obtained here: Sony Direct Accessory and Parts Center 8281 NW 107th Terrace Kansas City, MO 64153 (phone)1-800-488-7669

As for tape saturation, I'm using metal Type IV with Dolby B and not even allowing the peak light to go on. Even then, student flutists can punch into overload without warning for a split second. I've found that a professional flutist, who has much more breath and tone control, is easier to predict and record. I've burned my tapes onto CD at 16/44.1, adding a slight room ambience with WinOnCD 6.0 to compensate for the hall's dry sound. Amateur flutists tend to cut their notes too short, which is exacerbated by the relative deadness of the hall. The tiny bit of ambience makes for a recording that will please their parents (and perhaps encourage them to continue paying for the flute lessons?). I'm sure they'll be surprised at how the recordings came out; I sure am, and I still have a lot to learn.

-- Bob Brown (robebrown@rcn.com), March 07, 2000.


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