From: Geoff Sample <>
>
> Date: Mon, 22 Mar 2004 12:11:52 -0500
> From: Walter Knapp <>
> Subject: Re: New Sennheiser mic and frogs
>
>
>>> I guess that would be true, the polar pattern of the 40 is wider, but
>>> with the back lobe of the 50 combined with the pickup of the 30 it woul=
d
>>> appear wider. What you say makes sense. I should investigate M/S with
>>> the 80 pair with the mid set on hypercardioid and see what it's like.
>
>
> Damn it, I've been thinking that the 50 also had a wider frontal pick-up
> than the 40; I've just been and checked the graph plot (first time in yea=
rs)
> and you're right. And yet it has sounded ... if not wider, at least 'bigg=
er'
> in combination with the 30. I'm going to have to investigate these 2 set-=
ups
> again. In theory the 30/40 combination should be the better choice in
> certain situations where I've been using the 30/50. Spain at the end of
> April should be ideal for some comparisons: soundscapes of the dry
> rocky/sandy canyons of inland Valencia.
As I say, it's probably the effect of that rear lobe. It may be what you
are focusing on is not even width.
> Yes, agreed. Though I've never fully grasped what happens to sound picked=
up
> ONLY by the side mic. As I understand it, it's the sound to left and righ=
t
> picked up by BOTH mid and side mics that provides the exclusively L or R
> signal, when matrixed. The maths looks so simple, but I've always struggl=
ed
> to interpret it.
I do know that with the M/S 60/30 that the sounds off the back only
picked up by the side mic do appear in the recording. Trucks, barking
dogs, whatever. I'd love it to have a nice null back there.
I've always had a little conceptual problem of how a single diaphragm
pickup could be divided into the two sides. I know how to do it, know
the theory, and it does work, but it seems like the vibrations should be
passed through.
I can hear where the mid's influence dies off, and hear stuff wider than
that in the stereo image. Where it must be just side. The sound looses a
lot of it's 3d feeling past that boundary. But only if I concentrate on
that aspect. Otherwise it's a smooth illusion. Our mind fills in what it
expects.
>>>
>>> The SASS has a even field that wide, no dead areas I've noticed. In
>>> fact, hand held it's hard to find enough dead area in the back to
>>> breathe in. The mic sensitivity is enough to pick up my breathing.
>
>
> For walk-about stereo I use a short (5m) cable to avoid this. Put the mic=
s
> down on their small tripod, then just back off slightly to reduce shuffli=
ng,
> breathing and machine noise.
In a lot of my places putting a mic down would be hard on the mic, or
the tripod. To say nothing of where the ground slopes a lot. And I often
end up with subjects that I need to move aim, that can be done
soundlessly hand held, not so easy with tripods. I'm pretty used to what
I have to do to avoid being part of the recording while hand holding.
I got into mostly hand holding while I was doing the herp survey. The
purpose was to cover ground, the faster you could evaluate and document
a site the more sites you could cover. Hand held is far faster than any
kind of support. I got to where some sites I could do the whole process
in 5 minutes, evaluation, record, write field card, move on. Like hand
holding in photography, doing it well takes practice, and I've had lots
of that.
I do use a tripod some, primarily where I can set up for some time, or
want the high aspect of my tall tripod. I've come to like the high
tripod more and more. Does not help a whole lot as far as having to be
quiet. Can't move or it will pick it up still, though reasonable
breathing is no problem.
Last friday's recording I was doing the ultimate in such recording. Tall
tripod set up just clear of the cab door in the Ranger, cable run in the
nearly closed window. Avoiding the cold evening in some comfort. But I
only recorded in the one spot all evening.
Walt
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