Greg Winterflood wrote:
> The Marantz Cassette PMD222 arrived today - Friday. That's not bad.
> I ordered it around noon (Central Australian Time) last Thursday
> and it was here this morning. We're UTC (GMT) + 9.5 hours so I
> guess my order would have been read and processed in New York on
> (their) Thursday morning with the stuff arriving here on (their)
> Thursday evening. I was relieved to find that the whole outfit did
> not merit the attention of our Customs and Import Duty people!
> Today, in Coles SuperMarket, where I was buying batteries for the
> new recorder I ran into a radio-reporter friend-of-mine who
> regularly uses MiniDiscs and occasionally uses DAT. He told me that
> he ordered an iMac from Sydney two weeks ago, and it still isn't
> here. (I'll have to put the bite on him to borrow his DAT machine.)
Borrow his MD too. You'll be surprised at how good it is.
And you will want to get into NIMH rechargeable batteries for your
recorder. Higher capacity than alkaline and rechargeable for years of use.
> I had no idea my initial post saying that I had ordered a Marantz
> PMD222 Compact Cassette would create such a storm! Listening to you
> guys arguing the point has been a great way for me to learn. Vicki
> and Walt, I only intended to copy tapes directly to CD without any
> filtering beforehand; but it's getting pristine tapes that I have to
> work on now. I have to get material onto the tape and have realized
> that there are a few things that I don't know about - and there are
> no doubt heaps of things that I don't yet know that I don't know
> about!!
The key with cassette is that each pass through the machine degrades the
tape. So transfer right after recording, don't play it for a while
first. And don't store it away before for any longer than you have to.
> The Marantz doesn't have Dolby; but there is an ANC Selector, which
> I imagine is Automatic Noise Control. (I imagine this is not a Dolby
> imitator.) There are 3 choices Flat / Low Cut / High-&-Low Cut.
> Maybe this affects the response of a pre-amp behind the microphone
> input??? There is also a Record Mode Switch which allows me to
> choose between Manual (using the VU), Limiter (with reduction of
> transient high levels inputs) and Automatic Level Control (which
> sets the recording level automatically). To what???
You want to use Manual setting. Automatic Level Control will tend to
"hunt", running the gain up and down as it does so. Such recordings are
very hard to filter and can sound really strange. You don't want to get
into depending on the limiter, even if it does manage to limit the
transients without adding it's own noise signature (which most limiters
do). Learn to set the meter. With Cassette you want the peak reading on
the high transients to reach the 0 on the meter, or maybe slightly
above. You don't have the hard clipping of a digital recorder to deal
with. This will maximize the dynamic range you record, that's a much
more limited parameter with cassette than it is with digital. Learn
early to estimate the sound level for the entire recording. It's easier
to filter a recording that you did not change the gain while recording.
Also read the manual carefully on setting levels. And on tape type
recommendations. Use the type of tape it recommends, though you may want
to look around as to brand. I used to use Sony tape when I was still
recording with Cassette. Some brands would gum up the heads quickly, or
have other problems. Sony gave me the best all around performance.
Flat will give as flat a frequency response as the recorder is capable
of. Low Cut is the same as the roll-off on the mic, though it's specs
may differ slightly. And High cut rolls off the high frequencies,
sometimes useful if what your recording is not in those frequencies as
you can cut out some hiss (from the tape, wind noise, whatever). Listen
to what you are getting and choose what you like the best. The manual
should give the specs.
> Along with the Cassette Recorder came the Audio-Technica AT815b. It
> has a recessed switch which allows switching in/out of a roll-off in
> frequency response. The roll-off cuts out sounds in the 50-200Hz
> range. Thing is - there is no indication in the documentation as to
> which way to slide the switch to get the desired effect.
The desired effect is whichever way sounds the best to you, you are in
charge. In general the roll-off will cut out some of the background
rumble, so is often wanted. But, if your subject calls in those
frequencies, then you won't want it. I prefer to record without roll off
and filter later if needed.
> That's the technical stuff; but now I need to know how to use a
> shotgun mike in practice.
>
> I've walked around the backyard, looking as if I'm using a Geiger
> counter, and all I hear is NOISE with birdsong in the background.
> The noise is coming from cars in the street, babies next door,
> budgerigars in cages over the alley way. I had thought the shotgun
> would reject much of this.
Realize just how good a noise filter your brain is. Your ears have been
picking up all that noise, but your brain has not been passing it on to
you. You have found the bane of nature recording, the mic has no brain
to sort things out. This is the first big surprise for most who get into
nature recording. You will learn to listen in a whole new way. And will
begin to value the quiet places and become expert at finding them.
You can compensate somewhat by getting closer to your subject. But
realize these are live, thinking critters, and may change what they
sing. Closer will make the calls relatively louder compared to the
noise. Some filtering after the fact can also help, though if you want
the ambiance of the area you can't do much of that. If you want just the
bird you can be really drastic.
A shotgun mic does have some directionality, i.e. it's most sensitive
along it's axis. But you are talking a angle of acceptance of 60-90
degrees, and even off axis gets in if it's loud enough. And the shotgun
mic provides no amplification over a regular mic of the same
sensitivity. Focus on a single sound, like a bird, and slowly swing the
mic back and forth to become familiar with it's angle of acceptance.
Even in the quietest site you won't totally eliminate noise, the mic
itself is producing a low level of noise off it's electronics. Amplify a
quiet site and this can be very, very noticeable. This is one of the
main factors causing nature recordists to spend huge sums on mics as
they progress in the hobby. Mics vary in the amount of noise they
produce and producing little noise is a serious design problem.
> So for some more questions: Is a parabola much better at
> rejection??? Do people set up shotguns on a shockproof mount
> pointed at a likely tree and sit and wait? How long a cable can you
> run from an AT815b before the cable loss makes things not
> worthwhile??
A parabola has a much narrower angle of acceptance. And, on top of that
the reflector adds gain along the axis. Yes, it's much better for
picking out a single caller. And it's more than just the angle of
acceptance.
The way to think of it is a term that has no exact technical meaning,
but which we understand, that term is "reach". A specific mic can
"reach" out so far and get a good recording. Try to push for more
distance and the recording quality falls off rapidly. In this regard a
parabolic has more reach than a shotgun mic. Both, within their own
limits can do excellent recordings. At the other end of the distance
spectrum, as the subject is closer and closer the parabolic will not be
able to do well as close as a shotgun, so reach is really a near and far
limit. Note that the original design of a shotgun is to pick up dialog
on a movie or TV set without getting into the shot. While also limiting
the outside noise sources. 15-20' would be far for that. Nature
recordists push shotguns way outside of what they were designed for, but
there are limits.
Another hint from the movie and TV sets is where they typically have
that mic, overhead pointing downward. This makes for a cone of reception
rather than reaching out beyond your subject. Getting a directional mic
high and pointing down works for nature recording too. How high? Well,
here's the highest I go right now:
http://wwknapp.home.mindspring.com/tall.tripod.2.jpg
The mic in the photo is a Telinga Pro V with stereo element. I was
recording river frogs from a distance of about 100 yards. In this case
it's pointed horizontal and is up there to avoid some of the noise that
travels along ground level. But later the same evening with a SASS mic I
recorded River Frogs from about 25' with the tall mic pointed downward
at the frogs. Avoiding the highway noise from the highway that was only
3 miles away. This is what my SASS mics look like:
http://frogrecordist.home.mindspring.com/docs/my_mod_sass.html
Note that most recording I do the mic is hand held, so not that high. I
also always record in stereo. That way it's easier to sort out a call
when listening, even if the soundfield is very busy. I record mostly
frogs, and there can be as many as 8 different frog species calling in a
patch of wetland, by the hundreds.
Even at ground level, take advantage of the directionality of the mic.
Position yourself so the minimal sensitivity direction of the mic is
pointing at the sound sources you don't want when you have it's main
axis pointed at the bird.
Setting up a mic in a fixed position to record a bird depends on having
a species that has a singing perch it always uses. Works well for people
like Syd Curtis with his Lyrebirds, works poorly with a mockingbird who
dances around from place to place in the area around his preferred
perch. Assume you will want to be holding the mic mounted in a shock
mount so that you can follow the calls. You can see the fancy standard
type mount here, which is either hand holdable or tripod mount:
http://frogrecordist.home.mindspring.com/docs/my_ms_setups.html
The MKH-60 is a high end short shotgun similar to yours in general
terms. My setups are stereo, with a 2nd figure 8 mic for M/S stereo, but
the suspensions and windscreens are those designed for a mono mic for
most of those. BTW, the new price of the suspensions/windscreens shown
is way above the price of your mic. But there are ways to do it
handmade. Shock mount is the easy part to make, windscreen is more tricky.
You could probably run several hundred feet of cable, depending on how
many sources of electrical interference are in the area.
> Rich, I was intrigued by your plans to set up wireless mikes in the
> middle of a swamp.
>
> You wrote:
> "Just remember for a fixed center swamp location that a dish is a
> dish. You can extend a senn wireless mic as far as you want if you
> use a dish and keep in focus. On the receive end I think you can
> ignore the second diversity antenna if you use dishes and just
> confirm a good signal. With minor height changes being more of a
> factor than sides in confirming no dropout from alternate paths."
>
> Does this mean that you point a stand-alone wireless mike (shotgun,
> omnidirectional,parabolic?) at the quarry, with radio output from
> the mike sent via a parabolic-antenna to a receiving parabolic-
> antenna back on shore? I guess most wireless mikes are FM? I have
> made a few FM 'bugs' before. These had an outdoor range of over a
> couple of hundred metres. I'm wondering how these would work if
> placed in a tree (or swamp)? Guess it would depend on the quality of
> the FM receiver and it's output to a recorder?
Getting high quality sound out of a wireless link is a problem. The
wireless sets I have get around this by being both FM and encoding the
sound to a CD quality digital signal to send it and decoding that back
to analog at the receiver. I've not really had time to determine what
their actual range will be, but your estimate is what I'm expecting. The
transmitter has a short flexible whip antenna and is suitable to clip on
someone's clothing, like is done with the talking heads on the news, who
usually have the transmitter on their belt. My particular sets were
designed for transmitting from a guitar, so don't come with the mic.
I've got all the pieces together to set it up with my good mics just
have not had the time yet.
Rich was off into talking about putting a booster transmitter and
parabolic antenna on the set, but then realized that there were legal
power limits on the transmitter in his next message. Having a license as
a radio amateur, he could experiment on that, someone without the
license could not do so legally. I'm not sure if a better antenna could
be designed with the low power. I'll see if I need it first. I'm
actually more interested in a external antenna at the receiver, so I
could set the receivers up in the cab of my truck and not get bitten
while recording. And make powering the receivers easier.
And for Rich, I don't think the digital Sennheiser uses the diversity
antenna system. The receiver has a single "antenna" stuck inside the
plastic case, though it does have a single external antenna jack and
they do make a external antenna which I've never seen. I'll have to look
up the info again. I'll be running two complete transmitter/receiver
pairs to do stereo. Probably will fit it to the SASS/MKH-110 for a first
try, that avoids having to produce phantom power, though I have the
power supplies for that. And the SASS housing provides plenty of space
to stick the transmitters.
Walt
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