[genericaudioperson]

Hello,

I carefully (and appreciatively) read everyone's posts to my question
about shotgun mics. People kept talking about shotguns having
"horrible off-axis" response. what does that mean... is it
distortion, or the eq curve looks nothing like the on-axis one?

It came up so often that it must be a big deal. I'm just not sure why
it destroys the musical audio sound so much. Especially since not
much of that sound is making it to the mixer because it's part of the
sound array that the mic is (supposed to be) attenuating.

It seems like some sort of audio poison, like you only need a little
bit of it to destroy the sound.

[Richard Crowley]

"genericaudioperson" wrote ...
I carefully (and appreciatively) read everyone's posts to my question
about shotgun mics. People kept talking about shotguns having
"horrible off-axis" response. what does that mean... is it
distortion, or the eq curve looks nothing like the on-axis one?

It is the frequency-response curve of the off-axis performance that
is very different from the on-axis response. Sometimes you can
use that to advantage, but usually, it just bites you in the backside.

It came up so often that it must be a big deal. I'm just not sure why
it destroys the musical audio sound so much. Especially since not
much of that sound is making it to the mixer because it's part of the
sound array that the mic is (supposed to be) attenuating.

But again, mics don't attenuate the off-axis sound as much as you
seem to want to believe they do. Experimenting with some
different kinds of mics out in the Real World will answer many of
your questions, and several dozen you didn't know to ask yet.

If you are talking about reinforcement, poor off-axis response will
reach out and grab a feedback frequency and make your job hard.
Alternately, by getting the mic closer to the sound source, you can
increase the direct vs. ambient sound picked up by the mic to
counter this problem.

If you are talking about recording, poor off-axis response will alter
the sound of other nearby instruments (and/or the room itself) when
everything is mixed together.

These are just a couple of the first-order effects that make poor off-
axis response undesirable. But note that many popular mics suffer
from this poor off-axis response, but people have learned to live
with them because they may have other desirable qualities.

[Eeyore]

genericaudioperson wrote:

Hello,

I carefully (and appreciatively) read everyone's posts to my question
about shotgun mics. People kept talking about shotguns having
"horrible off-axis" response. what does that mean... is it
distortion,

NO.

or the eq curve looks nothing like the on-axis one?

It's not an 'eq curve' it's a polar response and IIRC it has lots of nasty
lobes.
http://books.google.com/books?id=d7f...m=12&ct=result



It came up so often that it must be a big deal. I'm just not sure why
it destroys the musical audio sound so much.

Did you know that air absorbs treble ? The further you mic, the less
treble is there. It's called air absorption.
http://www.sengpielaudio.com/calculator-air.htm
http://www.lsionline.co.uk/news/?YLZUGV

Graham

[Scott Dorsey]

genericaudioperson wrote:
I carefully (and appreciatively) read everyone's posts to my question
about shotgun mics. People kept talking about shotguns having
"horrible off-axis" response. what does that mean... is it
distortion, or the eq curve looks nothing like the on-axis one?

This is a very elementary question that is discussed in the FAQ and in
the Yamaha Sound Reinforcement Handbook.

But basically, if the frequency response off-axis is different than
the frequency response on-axis, then things will sound different
depending on where they are in the soundfield. This is bad.

It came up so often that it must be a big deal. I'm just not sure why
it destroys the musical audio sound so much. Especially since not
much of that sound is making it to the mixer because it's part of the
sound array that the mic is (supposed to be) attenuating.

Get an SM-57. Talk into it. Then talk into the side of it. Now, when
you pull the mike back and start getting room sound in the mike, most
of the room sound is coming from off-axis. For stereo miking, almost
everything is off-axis.

It seems like some sort of audio poison, like you only need a little
bit of it to destroy the sound.

Yes. Try far-field miking with an SM-57 and you'll see why.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."