From: "Laura Davids Todd" <>
>
> Thanks everyone who has advised me about minidisc recorders. Now I
> have to ask basic mic questions. I have a printout from someone who
> built a "T Style Stereo Mike for MiniDisc. "How to make a stereo or
> binaural T style mike for about $10".
> www.mindisc.org/jim_coon/
>
> He bought 2 condenser mikes from Radio Shack ($2) and wired them up
> with wiring from ear-buds. He placed them on either end of some kind
> of polyethylene tubing. He cut off the ear buds & used the plug to
> plug into his recording unit.
>
> Does this make sense to anyone? I know nothing about mics but if I can
> get some for $2 that will work with a bit of creative placement... I'm
> going for it!
These are a common item on ebay, so easy to make. They have problems,
but for the price, I guess you get what you pay for. If plugged into the
recorder directly, they will pick up all the internal noise of the
recorder, so for any chance at all, use them on a longer cable.
The stereo field definition is not generally accurate, but most folks
only notice a stereo effect, not the placement of callers.
The capsules, or cheap mics used are generally pretty low sensitivity
and lots of self noise. So, this sort of mic will only work with pretty
loud sounds recorded up close.
The original intent of such mics was to record voice up close. That
brings up another issue, particularly in the recording of insects like
you want to do. These mics typically are designed for voice frequency
ranges, won't do a good job at the higher frequencies of many insects.
> What's best? "stereo", Omni directional, cardioid, binaural?
I prefer true stereo. But, that can be recorded with different polar
pattern mics, the omni and cardioid are two different polar patterns.
Omni records fairly evenly from all directions, cardioid from something
a little more than a half circle, making it directional. The directional
aspect means you can in some cases work so unwanted noise is attenuated
by being behind the mic. Binaural, as popularly use is somewhat
meaningless. It's used to designate two tiny mics mounted on the person
somewhere near the head. That's a imitation of the true technical
binaural, where a mic is worn at the entrance of the ear canal in a
attempt to make it so there is no overlap in the sound path between
recording and playback. True binaural can generally only be correctly
listened to with headphones. This limitation will probably always keep
it limited to specialist recordings.
I do use a quasi-binaural mic quite a bit. That's the SASS mic. It
preserves the geometry of a human head in a very stylized manner, and
it's recordings can be played on speakers.
There is no such thing as best. Different mic setups work best at
different things. You choose the mic based on what you are trying to
record. Not generally so much the specific animal, but the geometry of
the zone you are trying to record in relation to mic location. And the
characteristics of the soundfield. In general, the quieter the
soundfield, and the farther away, the more demanded of the mic, and thus
greater cost. If you can get right at your subject, and they are
reasonably loud, there are far less restrictions on mic choice.
> Also, people have been talking about 'boom' mics for zooming in to
> high-up or far-off noises... but why not just mount your mic on a nice
> long stick, using duct tape?
I hardly ever use a mic boom. I have them, but it's rare that such a
small distance increase will get me significantly closer to the subject.
A short boom might be nice for insects as you would end up bending over
less. A boom can be a source of handling noise and you need to isolate
the mic from it's vibrations.
No, it does not have to be a formal, and very expensive mic boom. I'd
not be fond of tape but velcro straps to any kind of light support
that's long enough would work, though some suspension would be better.
One place to look for less expensive supports is the paint stores. Look
at what they have for extending the reach of paint rollers.
I do use a tall tripod. Sound outdoors close to the ground has lots of
reflections off local objects and so on. By placing the mic very high
(15' or more is what I'm using) you get it up into less complex sound
and get cleaner recordings a lot of the time.
One advantage of commercial booms is that most can be collapsed down to
much smaller length for transport. Don't forget you have to transport
your equipment.
Walt
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