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MXL 603s as choir mics?

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Anonymous
December 7, 2004 12:26:47 PM

Archived from groups: rec.audio.pro (More info?)

Ever wonder what a pair of MXL 603s sound like on a choir?

http://www.pcavtech.com/test_data/heard_about.mp3

Technical comments only.

More about : mxl 603s choir mics

Anonymous
December 7, 2004 12:26:48 PM

Archived from groups: rec.audio.pro (More info?)

"Arny Krueger" <arnyk@hotpop.com> wrote in message
news:o 7CdnSIgXYWBIyjcRVn-jw@comcast.com...
> Ever wonder what a pair of MXL 603s sound like on a choir?
>
> http://www.pcavtech.com/test_data/heard_about.mp3
>
> Technical comments only.

What was the mic positioning and the room like, etc? Also what preamp?
There is something I don't like about this recording that I can't quite
pinpoint. It's like it was recorded with a couple of low end dynamics, not
.. . .low end condensers. Sounds muddier and not as bright/clear as I would
of expected for MXL 603s mics.

John L Rice
Drummer@ImJohn.com
Anonymous
December 7, 2004 1:18:18 PM

Archived from groups: rec.audio.pro (More info?)

"John L Rice" <Drummer@ImJohn.com> wrote in message
news:10rbh02ioa946ff@corp.supernews.com
> "Arny Krueger" <arnyk@hotpop.com> wrote in message
> news:o 7CdnSIgXYWBIyjcRVn-jw@comcast.com...
>> Ever wonder what a pair of MXL 603s sound like on a choir?
>>
>> http://www.pcavtech.com/test_data/heard_about.mp3
>>
>> Technical comments only.
>
> What was the mic positioning and the room like, etc?

Mics were widely-spaced. The recording location was the balcony of a
neo-traditional church that seats up to 450.

>Also what preamp?

Preamps of a Mackie SR32.

>There is something I don't like about this recording that I can't quite
>pinpoint.

OK, we're on the same page here.

> It's like it was recorded with a couple of low end dynamics, not . . .low
> end condensers.

Can you translate into more details about the sonic character?

> Sounds muddier and not as bright/clear as I would of expected for MXL
> 603s mics.

Interesting.

Please compare that file to this file:

http://www.pcavtech.com/test_data/heard_about0.mp3

note the trailing zero on the file name.

I am uploading it as I type. Should be online in a few minutes.
Related resources
Anonymous
December 7, 2004 4:30:53 PM

Archived from groups: rec.audio.pro (More info?)

"Arny Krueger" <arnyk@hotpop.com> wrote in message
news:j6qdnUxC8rapVyjcRVn-vA@comcast.com...
> "John L Rice" <Drummer@ImJohn.com> wrote in message
> news:10rbh02ioa946ff@corp.supernews.com
> > "Arny Krueger" <arnyk@hotpop.com> wrote in message
> > news:o 7CdnSIgXYWBIyjcRVn-jw@comcast.com...
> >> Ever wonder what a pair of MXL 603s sound like on a choir?
> >>
> >> http://www.pcavtech.com/test_data/heard_about.mp3
> >>
> >> Technical comments only.
> >
> > What was the mic positioning and the room like, etc?
>
> Mics were widely-spaced. The recording location was the balcony of a
> neo-traditional church that seats up to 450.
>
> >Also what preamp?
>
> Preamps of a Mackie SR32.
>
> >There is something I don't like about this recording that I can't quite
> >pinpoint.
>
> OK, we're on the same page here.
>
> > It's like it was recorded with a couple of low end dynamics, not . .
..low
> > end condensers.
>
> Can you translate into more details about the sonic character?
>
> > Sounds muddier and not as bright/clear as I would of expected for MXL
> > 603s mics.
>
> Interesting.
>
> Please compare that file to this file:
>
> http://www.pcavtech.com/test_data/heard_about0.mp3
>
> note the trailing zero on the file name.
>
> I am uploading it as I type. Should be online in a few minutes.

Something sounds grainy to me. It sticks out in the first few seconds of the
first sample, but it feels to me like it continues right through the sample.
Maybe it's just MP3 compression artifacts but it almost sounds like it went
through a 12 bit converter. The second sample sounds like the first with
some EQ and a different reverb field, I'd guess from a pair of mics
positioned a little closer along the balcony?

Sean
Anonymous
December 7, 2004 6:29:14 PM

Archived from groups: rec.audio.pro (More info?)

"John L Rice" <Drummer@ImJohn.com> wrote in message
news:10rbh02ioa946ff@corp.supernews.com...
>
> "Arny Krueger" <arnyk@hotpop.com> wrote in message
> news:o 7CdnSIgXYWBIyjcRVn-jw@comcast.com...
>> Ever wonder what a pair of MXL 603s sound like on a choir?
>>
>> http://www.pcavtech.com/test_data/heard_about.mp3
>>
>> Technical comments only.
>
> What was the mic positioning and the room like, etc? Also what preamp?
> There is something I don't like about this recording that I can't quite
> pinpoint. It's like it was recorded with a couple of low end dynamics,
> not
> . . .low end condensers. Sounds muddier and not as bright/clear as I would
> of expected for MXL 603s mics.
>
> John L Rice
> Drummer@ImJohn.com
>
>

Just my personal opinion. I've heard good reports about these mics for their
cost but listening to the mp3 it appears these mics are not at home with
choirs. I agree with John I feel it just doesn't have the finesse of a good
condenser. I heard a wide but instinct soundstage though how much of that
was due to the mics though? I'd also be interested to see answers to Johns
questions.

Mike
Anonymous
December 7, 2004 6:38:07 PM

Archived from groups: rec.audio.pro (More info?)

"Arny Krueger" <arnyk@hotpop.com> wrote in message
news:j6qdnUxC8rapVyjcRVn-vA@comcast.com...
> "John L Rice" <Drummer@ImJohn.com> wrote in message
> news:10rbh02ioa946ff@corp.supernews.com
>> "Arny Krueger" <arnyk@hotpop.com> wrote in message
>> news:o 7CdnSIgXYWBIyjcRVn-jw@comcast.com...
>>> Ever wonder what a pair of MXL 603s sound like on a choir?
>>>
>>> http://www.pcavtech.com/test_data/heard_about.mp3
>>>
>>> Technical comments only.
>>
>> What was the mic positioning and the room like, etc?
>
> Mics were widely-spaced. The recording location was the balcony of a
> neo-traditional church that seats up to 450.
>
>>Also what preamp?
>
> Preamps of a Mackie SR32.
>
>>There is something I don't like about this recording that I can't quite
>>pinpoint.
>
> OK, we're on the same page here.
>
>> It's like it was recorded with a couple of low end dynamics, not . .
>> .low end condensers.
>
> Can you translate into more details about the sonic character?
>
>> Sounds muddier and not as bright/clear as I would of expected for MXL
>> 603s mics.
>
> Interesting.
>
> Please compare that file to this file:
>
> http://www.pcavtech.com/test_data/heard_about0.mp3
>
> note the trailing zero on the file name.
>
> I am uploading it as I type. Should be online in a few minutes.
>
>
>
>
Preferred that to your earlier mp3. More definition for individual voices
but the recording has same signature that still doesn't have the feel of a
condenser pair.
What changed?

Mike
Anonymous
December 7, 2004 7:30:36 PM

Archived from groups: rec.audio.pro (More info?)

"Mike Gilmour" <mike@tfjazz.freeserve.co.uk> wrote in message
news:3NednTEne_D8UyjcRVn-tw@nildram.net
> "Arny Krueger" <arnyk@hotpop.com> wrote in message
> news:j6qdnUxC8rapVyjcRVn-vA@comcast.com...
>> "John L Rice" <Drummer@ImJohn.com> wrote in message
>> news:10rbh02ioa946ff@corp.supernews.com
>>> "Arny Krueger" <arnyk@hotpop.com> wrote in message
>>> news:o 7CdnSIgXYWBIyjcRVn-jw@comcast.com...
>>>> Ever wonder what a pair of MXL 603s sound like on a choir?
>>>>
>>>> http://www.pcavtech.com/test_data/heard_about.mp3
>>>>
>>>> Technical comments only.
>>>
>>> What was the mic positioning and the room like, etc?
>>
>> Mics were widely-spaced. The recording location was the balcony of a
>> neo-traditional church that seats up to 450.
>>
>>> Also what preamp?
>>
>> Preamps of a Mackie SR32.
>>
>>> There is something I don't like about this recording that I can't
>>> quite pinpoint.
>>
>> OK, we're on the same page here.
>>
>>> It's like it was recorded with a couple of low end dynamics, not .
>>> . .low end condensers.
>>
>> Can you translate into more details about the sonic character?
>>
>>> Sounds muddier and not as bright/clear as I would of expected for
>>> MXL 603s mics.
>>
>> Interesting.
>>
>> Please compare that file to this file:
>>
>> http://www.pcavtech.com/test_data/heard_about0.mp3
>>
>> note the trailing zero on the file name.
>>
>> I am uploading it as I type. Should be online in a few minutes.
>>
>>
>>
>>
> Preferred that to your earlier mp3. More definition for individual
> voices but the recording has same signature that still doesn't have
> the feel of a condenser pair.

> What changed?

Mastering. The zero version is unmastered, just mixed.
Anonymous
December 7, 2004 9:15:04 PM

Archived from groups: rec.audio.pro (More info?)

In article <j6qdnUxC8rapVyjcRVn-vA@comcast.com> arnyk@hotpop.com writes:

> Mics were widely-spaced. The recording location was the balcony of a
> neo-traditional church that seats up to 450.

I didn't listen to the file, but with a setup like that, I'd expect it
to be really muddy (mics too far away, too much reverberation) and
funny imaging, even on the ambience (mics widely spaced).

Is there something good about the recording?

--
I'm really Mike Rivers (mrivers@d-and-d.com)
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo
Anonymous
December 7, 2004 10:05:29 PM

Archived from groups: rec.audio.pro (More info?)

> >> Ever wonder what a pair of MXL 603s sound like on a choir?
> >>
> >> http://www.pcavtech.com/test_data/heard_about.mp3
> >>
> >> Technical comments only.
> >
> > What was the mic positioning and the room like, etc?
>
> Mics were widely-spaced. The recording location was the balcony of a
> neo-traditional church that seats up to 450.
>
> >Also what preamp?
>
> Preamps of a Mackie SR32.
>
> >There is something I don't like about this recording that I can't quite
> >pinpoint.
>
> OK, we're on the same page here.
>
> > It's like it was recorded with a couple of low end dynamics, not . .
..low
> > end condensers.
>
> Can you translate into more details about the sonic character?

Probably not, but I'll try. ;-)

The recording sounds like the top end and bottom end is rolled off.
No sparkle or resonant depth. It also sounds a little like it was recorded
with a limiter on, even though a choir of this type isn't going to be
tremndously dynamic, it just doesn't sound dynamic enough to me.
I get a subtle feeling of frustration/disappontment when they cresendo into
the louder passages because it sounds/feels 'held back'.
Sounds like it could of been recorded with a pair of SM57s with socks over
them. ( no offence intended! ;-)

As far as I can tell that room has WAY too long of a reverb time ( unless
this recording has reverb added etc ) Sounds like it's at least 3 to 4
seconds ( easiest to tell after the final note of the peice ). I would try
moving the mics closer to the choir and favor the tenors/basses a little
more.

>
> > Sounds muddier and not as bright/clear as I would of expected for MXL
> > 603s mics.
>
> Interesting.
>
> Please compare that file to this file:
>
> http://www.pcavtech.com/test_data/heard_about0.mp3
>
> note the trailing zero on the file name.
>
> I am uploading it as I type. Should be online in a few minutes.
>

This one is a lot more listenable to me. A little crisper and not as
'muted' sounding. Still sounds like I'd want to put the mics closer to the
choir. Maybe do one mic at the current position for room sound and then a
pair of mics as close as you can get them for the main sound.

Best of luck!

John L Rice
Drummer@ImJohn.com
Anonymous
December 7, 2004 11:59:09 PM

Archived from groups: rec.audio.pro (More info?)

Arny Krueger <arnyk@hotpop.com> wrote:
> Ever wonder what a pair of MXL 603s sound like on a choir?
>
> http://www.pcavtech.com/test_data/heard_about.mp3
>
> Technical comments only.
>
>
>

Hi,

One stupid question: is it sensible to try to judge a mic
by psychoacustically compressed audio? I am not quite sure
about this. If someone can point me to resources why this
is a good or bad idea please don't hesitate to tell me.

Best,

Ben
Anonymous
December 7, 2004 11:59:10 PM

Archived from groups: rec.audio.pro (More info?)

"Ben Hell" <ben@dev.null.uni-bielefeld.de> wrote in message
news:31mjsrF3detjiU1@news.dfncis.de
> Arny Krueger <arnyk@hotpop.com> wrote:
>> Ever wonder what a pair of MXL 603s sound like on a choir?
>>
>> http://www.pcavtech.com/test_data/heard_about.mp3
>>
>> Technical comments only.
>>
>>
>>
>
> Hi,
>
> One stupid question: is it sensible to try to judge a mic
> by psychoacustically compressed audio? I am not quite sure
> about this. If someone can point me to resources why this
> is a good or bad idea please don't hesitate to tell me.

Let's put it this way - if you are up for the download, I'll upload the
31.5 megabyte .wav file that was used to make the "zero" MP3 file. You can
then judge for yourself. Just post the word!
Anonymous
December 7, 2004 11:59:10 PM

Archived from groups: rec.audio.pro (More info?)

In article <31mjsrF3detjiU1@news.dfncis.de> ben@dev.null.uni-bielefeld.de writes:

> One stupid question: is it sensible to try to judge a mic
> by psychoacustically compressed audio?

It's probably not reasonable to judge a mic from an MP3 file, but it's
no unreasonable to judge technique, and I think that's the point of
this exercise. It's not the best way, of course, but it makes it
feasible for a larger number of people than if you were to mail them
all CDs or require that they download a file about 10 times larger.



--
I'm really Mike Rivers (mrivers@d-and-d.com)
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo
Anonymous
December 8, 2004 12:49:34 AM

Archived from groups: rec.audio.pro (More info?)

"Ben Hell" <ben@dev.null.uni-bielefeld.de> wrote in
message news:31mjsrF3detjiU1@news.dfncis.de...
: Arny Krueger <arnyk@hotpop.com> wrote:
: > Ever wonder what a pair of MXL 603s sound like on a
choir?
: >
: > http://www.pcavtech.com/test_data/heard_about.mp3
: >
: > Technical comments only.

NO BASS below 250 HZ. Perhaps the lack of proximity to
the source causes this or perhaps there is no bass in
the source, but I would pick the previous. . If you
used OMNI mics instead of the pseudo-cardioid 603 I bet
there would be much more full range sound and a better
image to boot.

Phil Abbate
Anonymous
December 8, 2004 12:49:35 AM

Archived from groups: rec.audio.pro (More info?)

"GoobAudio" <philsaudio-remove this and the dashes-@mindspring.com>
wrote in message
news:o zptd.9789$714.2149@newsread2.news.atl.earthlink.net
> "Ben Hell" <ben@dev.null.uni-bielefeld.de> wrote in
> message news:31mjsrF3detjiU1@news.dfncis.de...
>> Arny Krueger <arnyk@hotpop.com> wrote:
>>> Ever wonder what a pair of MXL 603s sound like on a choir?
>>>
>>> http://www.pcavtech.com/test_data/heard_about.mp3
>>>
>>> Technical comments only.
>
> NO BASS below 250 HZ. Perhaps the lack of proximity to
> the source causes this or perhaps there is no bass in
> the source, but I would pick the previous. . If you
> used OMNI mics instead of the pseudo-cardioid 603 I bet
> there would be much more full range sound and a better
> image to boot.

Actually, we set the gig up with omnis, and backed off to broad cardioids,
because of the feedback (SR) issues.
Anonymous
December 8, 2004 1:37:55 AM

Archived from groups: rec.audio.pro (More info?)

"Arny Krueger" <arnyk@hotpop.com> wrote in message
news:VLCdndvbAa4bsyvcRVn-hg@comcast.com...
: "GoobAudio" <philsaudio-remove this and the
dashes-@mindspring.com>
: wrote in message
:
news:o zptd.9789$714.2149@newsread2.news.atl.earthlink.net
: > "Ben Hell" <ben@dev.null.uni-bielefeld.de> wrote in
: > message news:31mjsrF3detjiU1@news.dfncis.de...
: >> Arny Krueger <arnyk@hotpop.com> wrote:
: >>> Ever wonder what a pair of MXL 603s sound like on
a choir?
: >>>
: >>> http://www.pcavtech.com/test_data/heard_about.mp3
: >>>
: >>> Technical comments only.
: >
: > NO BASS below 250 HZ. Perhaps the lack of
proximity to
: > the source causes this or perhaps there is no bass
in
: > the source, but I would pick the previous. . If you
: > used OMNI mics instead of the pseudo-cardioid 603 I
bet
: > there would be much more full range sound and a
better
: > image to boot.
:
: Actually, we set the gig up with omnis, and backed
off to broad cardioids,
: because of the feedback (SR) issues.


So these are not RECORDING mics they are SR mics in
your setup. No wonder you cant get it to sound right!
How about hooking up the omni's ONLY into the recorder
and using the 603s's for the PA.

I recall earlier the mics were on the balcony. Is this
because the choir is on the balcony? What the hell you
set up in there Arny? It is not like you to be so brief
in your presentation.

Phil
Anonymous
December 8, 2004 1:37:56 AM

Archived from groups: rec.audio.pro (More info?)

"GoobAudio" <philsaudio-remove this and the dashes-@mindspring.com>
wrote in message
news:7hqtd.9825$714.6208@newsread2.news.atl.earthlink.net
> "Arny Krueger" <arnyk@hotpop.com> wrote in message
> news:VLCdndvbAa4bsyvcRVn-hg@comcast.com...
>> "GoobAudio" <philsaudio-remove this and the dashes-@mindspring.com>
>> wrote in message
>>
> news:o zptd.9789$714.2149@newsread2.news.atl.earthlink.net
>>> "Ben Hell" <ben@dev.null.uni-bielefeld.de> wrote in
>>> message news:31mjsrF3detjiU1@news.dfncis.de...
>>>> Arny Krueger <arnyk@hotpop.com> wrote:
>>>>> Ever wonder what a pair of MXL 603s sound like on
> a choir?
>>>>>
>>>>> http://www.pcavtech.com/test_data/heard_about.mp3
>>>>>
>>>>> Technical comments only.
>>>
>>> NO BASS below 250 HZ. Perhaps the lack of
> proximity to
>>> the source causes this or perhaps there is no bass
> in
>>> the source, but I would pick the previous. . If you
>>> used OMNI mics instead of the pseudo-cardioid 603 I
> bet
>>> there would be much more full range sound and a
> better
>>> image to boot.
>>
>> Actually, we set the gig up with omnis, and backed
> off to broad cardioids,
>> because of the feedback (SR) issues.
>
>
> So these are not RECORDING mics they are SR mics in
> your setup. No wonder you cant get it to sound right!

Prejudices noted.

I record pretty much this same choir every week with a pair of omnis at the
other end of the room. By rights the SR system should interfere even more
with them over there, because the mics are omnis and the SR speakers are
about 80 feet closer.

Furthermore, at the point the recording interface is attached, the mics
aren't SR mics or recording mics. They are just mics attached to some mic
premps that happen to be inside a console that is primarily used for SR. The
record chain bypasses the enitre channel strips, except for the mic preamps.
Ditto for the mixing buses.

> How about hooking up the omni's ONLY into the recorder
> and using the 603s's for the PA.

I'm thinking about trying exactly that the next time, more or less.

> I recall earlier the mics were on the balcony. Is this
> because the choir is on the balcony?

Yep. The pews in the balcony are pretty similar to the pews in the choir
loft, except the choir loft is at the other end of the room and about 14
feet lower in elevation. Aside from the parts of the recording I don't
like, I definately like the fact that the choir was closer to the ceiling.
It gives a bit more focus to the sound.

> What the hell you set up in there Arny? It is not like you to be so brief
> in your presentation.

It's a pretty typical neo-traditional church. Long and skinny with a ca. 30
foot high, mostly flat ceiling. The main seating area is about 80 feet long
and maybe 35 feet wide. The choir loft is at one end, behind a vistigial
platform about 40 inches wide. The balcony is at the other end, over the
gathering area behind the seating area.
Anonymous
December 8, 2004 2:07:29 AM

Archived from groups: rec.audio.pro (More info?)

: Furthermore, at the point the recording interface is
attached, the mics
: aren't SR mics or recording mics. They are just mics
attached to some mic
: premps that happen to be inside a console that is
primarily used for SR. The
: record chain bypasses the enitre channel strips,
except for the mic preamps.
: Ditto for the mixing buses.

Arny:

Either the mics are in the SR loop or not. If you are
having feedback they are in the SR/PA loop for sure. If
you get SR feedback it will be fed into the recorder
and of course you know that other than a full on squeal
the little ringing and hallow sound that something on
the verge of feedback adds to a recording sounds like
s*it.

I am still unsure what you have hooked up, but IMHO
unless your recorder is completely signal isolated from
everything else your source (the choir) is not the only
source feeding the mics with the choir's sound and I
would recon that the SR speakers sound being picked up
by the mics are providing the weirdness you are
hearing.

Phil
Anonymous
December 8, 2004 3:05:41 AM

Archived from groups: rec.audio.pro (More info?)

Arny Krueger wrote:

> Furthermore, at the point the recording interface is attached, the mics
> aren't SR mics or recording mics. They are just mics attached to some mic
> premps that happen to be inside a console that is primarily used for SR. The
> record chain bypasses the enitre channel strips, except for the mic preamps.
> Ditto for the mixing buses.

How did the feedback get into play if the mics used didn't feed the
sound reinforcement system?

--
ha
Anonymous
December 8, 2004 3:05:42 AM

Archived from groups: rec.audio.pro (More info?)

"hank alrich" <walkinay@thegrid.net> wrote in message
news:1goflui.1dcj8y819yer8kN%walkinay@thegrid.net
> Arny Krueger wrote:
>
>> Furthermore, at the point the recording interface is attached, the
>> mics aren't SR mics or recording mics. They are just mics attached
>> to some mic premps that happen to be inside a console that is
>> primarily used for SR. The record chain bypasses the enitre channel
>> strips, except for the mic preamps. Ditto for the mixing buses.
>
> How did the feedback get into play if the mics used didn't feed the
> sound reinforcement system?

The choir mics do feed the SR system. But they are largely out of the direct
field.
Anonymous
December 8, 2004 7:21:05 AM

Archived from groups: rec.audio.pro (More info?)

Arny Krueger wrote:

> "hank alrich" wrote:
> > Arny Krueger wrote:

> >> Furthermore, at the point the recording interface is attached, the
> >> mics aren't SR mics or recording mics. They are just mics attached
> >> to some mic premps that happen to be inside a console that is
> >> primarily used for SR. The record chain bypasses the enitre channel
> >> strips, except for the mic preamps. Ditto for the mixing buses.

> > How did the feedback get into play if the mics used didn't feed the
> > sound reinforcement system?

> The choir mics do feed the SR system. But they are largely out of the direct
> field.

This is a problem both for the recording and for the SR. Do those jobs
separately. When you put distant mics into an SR system you are begging
for trouble. When you then use those mics to record the result of adding
those mics to the overall live sound, you are bound to record
bandlimited mush with trashed transients.

--
ha
Anonymous
December 8, 2004 9:35:41 AM

Archived from groups: rec.audio.pro (More info?)

On Tue, 7 Dec 2004 16:30:36 -0500, "Arny Krueger" <arnyk@hotpop.com>
wrote:

>"Mike Gilmour" <mike@tfjazz.freeserve.co.uk> wrote in message
>news:3NednTEne_D8UyjcRVn-tw@nildram.net

>> ... { cascade snipped }

>> Preferred that to your earlier mp3. More definition for individual
>> voices but the recording has same signature that still doesn't have
>> the feel of a condenser pair.
>
>> What changed?
>
>Mastering. The zero version is unmastered, just mixed.

Was there a reason why the channels were swapped? Was this a
"mastering decision"?

-----
http://mindspring.com/~benbradley
Anonymous
December 8, 2004 11:04:28 AM

Archived from groups: rec.audio.pro (More info?)

"Ben Bradley" <ben_nospam_bradley@mindspring.com> wrote in message
news:b18dr0djmj7v81l5d5edei8jkljvlg6865@4ax.com
> On Tue, 7 Dec 2004 16:30:36 -0500, "Arny Krueger" <arnyk@hotpop.com>
> wrote:
>
>> "Mike Gilmour" <mike@tfjazz.freeserve.co.uk> wrote in message
>> news:3NednTEne_D8UyjcRVn-tw@nildram.net
>
>>> ... { cascade snipped }
>
>>> Preferred that to your earlier mp3. More definition for individual
>>> voices but the recording has same signature that still doesn't have
>>> the feel of a condenser pair.
>>
>>> What changed?
>>
>> Mastering. The zero version is unmastered, just mixed.
>
> Was there a reason why the channels were swapped? Was this a
> "mastering decision"?

The multitrack master's channel assignments was a mess because of broken
inputs on the console and the fact that the choir mics were set up at the
last minute. The choir mics ended up on channels 4 and 7 of 12 on the
recording, and were in turn taken from two vastly different unused inputs on
the console. I did the zero mix and then realized that the channels were
swapped. I then corrected it, and spent more time trying to fine-tune it to
make the first mix I posted.
Anonymous
December 8, 2004 11:11:19 AM

Archived from groups: rec.audio.pro (More info?)

"hank alrich" <walkinay@thegrid.net> wrote in message
news:1gofxpt.1h8qlxc7w79v8N%walkinay@thegrid.net
> Arny Krueger wrote:
>
>> "hank alrich" wrote:
>>> Arny Krueger wrote:
>
>>>> Furthermore, at the point the recording interface is attached, the
>>>> mics aren't SR mics or recording mics. They are just mics attached
>>>> to some mic premps that happen to be inside a console that is
>>>> primarily used for SR. The record chain bypasses the enitre channel
>>>> strips, except for the mic preamps. Ditto for the mixing buses.
>
>>> How did the feedback get into play if the mics used didn't feed the
>>> sound reinforcement system?
>
>> The choir mics do feed the SR system. But they are largely out of
>> the direct field.
>
> This is a problem both for the recording and for the SR. Do those jobs
> separately. When you put distant mics into an SR system you are
> begging for trouble. When you then use those mics to record the
> result of adding those mics to the overall live sound, you are bound
> to record bandlimited mush with trashed transients.

Let's put it this way - I often to a better job of getting away with
breaking most if not all of these not unreasonable rules. We were ultimately
able to get quite a bit of acoustic gain without feedback, mostly because
the SR system speakers were so far away.

Another listener properly identified the fact that the room is highly
reverberant, and that's just the room, not the effects of SR system. If
anything, the SR system slightly evened out the reverb decay of the room,
which has a big slap about 150-200 milliseconds out.

What I hear that is the worst thing wrong with this recording seems to track
the singers very closely - within less than 20 milliseconds of the origin
sound.
Anonymous
December 8, 2004 3:31:15 PM

Archived from groups: rec.audio.pro (More info?)

On Tue, 7 Dec 2004 09:26:47 -0500, Arny Krueger wrote
(in article <o7CdnSIgXYWBIyjcRVn-jw@comcast.com>):

> http://www.pcavtech.com/test_data/heard_about.mp3

Arny,

Hard to tell a lot about ANY mic from an mp3, of course.

A tough assignment. Sounds like a lot of people to cover with two mics. You
have to pull back to get em all in and then you have too much room.

I wasn't there, so I can't tell what might have been a better position.

Sounds a little boxy, but it ma well have been the room. You can hear how
long the reverb trails are at the end of the tune; fairly long RT60. That in
a murky space could clean up a bit of the low mid/upper bass. Tighter pattern
or moving mics a bit closer to get more direct field might also help.
Or, consider using three mics (LCR) and move in closer to reduce the room
sound.

I'm sure the group was thrilled though.

Thanks for sharing. If anyone's interested, I can put up an mp3 of a six
person madrigal group in a church; a simple coincident cmc641.

Regards,

Ty Ford



-- Ty Ford's equipment reviews, audio samples, rates and other audiocentric
stuff are at www.tyford.com
Anonymous
December 8, 2004 3:34:33 PM

Archived from groups: rec.audio.pro (More info?)

On Tue, 7 Dec 2004 17:26:24 -0500, Arny Krueger wrote
(in article <VLCdndvbAa4bsyvcRVn-hg@comcast.com>):

> "GoobAudio" <philsaudio-remove this and the dashes-@mindspring.com>
> wrote in message
> news:o zptd.9789$714.2149@newsread2.news.atl.earthlink.net
>> "Ben Hell" <ben@dev.null.uni-bielefeld.de> wrote in
>> message news:31mjsrF3detjiU1@news.dfncis.de...
>>> Arny Krueger <arnyk@hotpop.com> wrote:
>>>> Ever wonder what a pair of MXL 603s sound like on a choir?
>>>>
>>>> http://www.pcavtech.com/test_data/heard_about.mp3
>>>>
>>>> Technical comments only.
>>
>> NO BASS below 250 HZ. Perhaps the lack of proximity to
>> the source causes this or perhaps there is no bass in
>> the source, but I would pick the previous. . If you
>> used OMNI mics instead of the pseudo-cardioid 603 I bet
>> there would be much more full range sound and a better
>> image to boot.
>
> Actually, we set the gig up with omnis, and backed off to broad cardioids,
> because of the feedback (SR) issues.
>
>

THERE WAS A PA!! You didn't mention that!


Ty Ford


-- Ty Ford's equipment reviews, audio samples, rates and other audiocentric
stuff are at www.tyford.com
Anonymous
December 8, 2004 7:15:08 PM

Archived from groups: rec.audio.pro (More info?)

Arny Krueger wrote:

> What I hear that is the worst thing wrong with this recording seems to track
> the singers very closely - within less than 20 milliseconds of the origin
> sound.

That's a number, not a measure of sound _quality_, and when you return
that 20 ms. to the SR system and record it, what you get is what you
got.

--
ha
Anonymous
December 8, 2004 7:50:40 PM

Archived from groups: rec.audio.pro (More info?)

"hank alrich" <walkinay@thegrid.net> wrote in message
news:1gogtjp.5wuot512pwxmoN%walkinay@thegrid.net
> Arny Krueger wrote:
>
>> What I hear that is the worst thing wrong with this recording seems
>> to track the singers very closely - within less than 20 milliseconds
>> of the origin sound.
>
> That's a number, not a measure of sound _quality_, and when you return
> that 20 ms. to the SR system and record it, what you get is what you
> got.

Having done similar thiings many times in the same room, the results were
unexpected.
Anonymous
December 8, 2004 7:51:29 PM

Archived from groups: rec.audio.pro (More info?)

"Ty Ford" <tyreeford@comcast.net> wrote in message
news:EJOdnV3GfvW0pircRVn-2A@comcast.com
> On Tue, 7 Dec 2004 17:26:24 -0500, Arny Krueger wrote
> (in article <VLCdndvbAa4bsyvcRVn-hg@comcast.com>):
>
>> "GoobAudio" <philsaudio-remove this and the dashes-@mindspring.com>
>> wrote in message
>> news:o zptd.9789$714.2149@newsread2.news.atl.earthlink.net
>>> "Ben Hell" <ben@dev.null.uni-bielefeld.de> wrote in
>>> message news:31mjsrF3detjiU1@news.dfncis.de...
>>>> Arny Krueger <arnyk@hotpop.com> wrote:
>>>>> Ever wonder what a pair of MXL 603s sound like on a choir?
>>>>>
>>>>> http://www.pcavtech.com/test_data/heard_about.mp3
>>>>>
>>>>> Technical comments only.
>>>
>>> NO BASS below 250 HZ. Perhaps the lack of proximity to
>>> the source causes this or perhaps there is no bass in
>>> the source, but I would pick the previous. . If you
>>> used OMNI mics instead of the pseudo-cardioid 603 I bet
>>> there would be much more full range sound and a better
>>> image to boot.
>>
>> Actually, we set the gig up with omnis, and backed off to broad
>> cardioids, because of the feedback (SR) issues.
>>
>>
>
> THERE WAS A PA!! You didn't mention that!

I mentioned as little as possible to get a better idea about what people
heard.
Anonymous
December 8, 2004 8:56:44 PM

Archived from groups: rec.audio.pro (More info?)

Ty Ford wrote:

> THERE WAS A PA!! You didn't mention that!

<j>

Omnis work purdy good with PA?

</j>

--
ha
Anonymous
December 8, 2004 8:56:45 PM

Archived from groups: rec.audio.pro (More info?)

"hank alrich" <walkinay@thegrid.net> wrote in message
news:1gogzkc.em0yeic4mgn4N%walkinay@thegrid.net
> Ty Ford wrote:
>
>> THERE WAS A PA!! You didn't mention that!
>
> <j>
>
> Omnis work purdy good with PA?

Only in special cases, as you no doubt know.
Anonymous
December 8, 2004 8:58:15 PM

Archived from groups: rec.audio.pro (More info?)

Ty Ford wrote:

> You can hear how
> long the reverb trails are at the end of the tune; fairly long RT60.

And that is fed back into the SR system fom the mics...

"Listen pal, this here RT60 ain't nearly long enough, so here's what I'm
a'gonna do..."

--
ha
Anonymous
December 8, 2004 8:58:16 PM

Archived from groups: rec.audio.pro (More info?)

"hank alrich" <walkinay@thegrid.net> wrote in message
news:1gogzmb.3ekbpm1jdyiyoN%walkinay@thegrid.net
> Ty Ford wrote:
>
>> You can hear how
>> long the reverb trails are at the end of the tune; fairly long RT60.

I can hear it all through the song! ;-)

> And that is fed back into the SR system fom the mics...

> "Listen pal, this here RT60 ain't nearly long enough, so here's what
> I'm a'gonna do..."

In this case the results of the feedback was arguably more euphonic than
usual. The ca.80 mSec delay from the SR speakers at the other end of the
room gave a more even-sounding reverb tail than the room's usual 150-200
msec action.

Looking at the reverb tail that starts with the end last note sung around
2:55.245, there are a lot of peaks following it that are 72-82 mSec apart.
IMO that was a good result. That longer delay ca. 200 mSec echo is more
distracting. I can't help wonder if the shorter echo made it easier for the
choir to sing, because they are in exceptionally good form for them.

The bad result I hear is a nasty sibilant hot sort of sound that is pretty
tight with the singing.
Anonymous
December 8, 2004 9:38:15 PM

Archived from groups: rec.audio.pro (More info?)

"GoobAudio" <philsaudio-remove this and the dashes-@mindspring.com>
wrote in message
news:RIqtd.8302$Va5.5306@newsread3.news.atl.earthlink.net
>> Furthermore, at the point the recording interface is attached, the
>> mics aren't SR mics or recording mics. They are just mics attached
>> to some mic premps that happen to be inside a console that is
>> primarily used for SR. The record chain bypasses the enitre channel
>> strips, except for the mic preamps. Ditto for the mixing buses.

> Either the mics are in the SR loop or not. If you are
> having feedback they are in the SR/PA loop for sure.

A properly-operating SR system lacks feedack. Switching the mics from
omnis to cardioids allowed more gain before feedback.

> If you get SR feedback it will be fed into the recorder
> and of course you know that other than a full on squeal
> the little ringing and hallow sound that something on
> the verge of feedback adds to a recording sounds like
> s*it.

yes, I know that so it wasn't an issue.

> I am still unsure what you have hooked up,

It's pretty straight-forward. Do much SR work?

> but IMHO unless your recorder is completely signal isolated from
> everything else your source (the choir) is not the only
> source feeding the mics with the choir's sound and I
> would recon that the SR speakers sound being picked up
> by the mics are providing the weirdness you are
> hearing.

The SR speakers are about 80 feet away, so anything from them would be
delayed by 80 milliseconds or so, which is a very noticable amount. I would
expect contamination from that source to be audible as a kind of an echo.
Anonymous
December 8, 2004 10:15:48 PM

Archived from groups: rec.audio.pro (More info?)

"hank alrich
> Arny Krueger wrote:
>
>> >> Furthermore, at the point the recording interface is attached, the
>> >> mics aren't SR mics or recording mics. They are just mics attached
>> >> to some mic premps that happen to be inside a console that is
>> >> primarily used for SR. The record chain bypasses the enitre channel
>> >> strips, except for the mic preamps. Ditto for the mixing buses.
>
>> > How did the feedback get into play if the mics used didn't feed the
>> > sound reinforcement system?
>
>> The choir mics do feed the SR system. But they are largely out of the
>> direct
>> field.
>
> This is a problem both for the recording and for the SR. Do those jobs
> separately. When you put distant mics into an SR system you are begging
> for trouble. When you then use those mics to record the result of adding
> those mics to the overall live sound, you are bound to record
> bandlimited mush with trashed transients.
>


** The signal output from a microphone depends only on the actual sound
pressure variations that are happening in the air where it is located. It
makes no difference that the same mic may be connected to a PA or SR system.

If in doubt - read the first sentence again.





................. Phil
Anonymous
December 8, 2004 10:15:49 PM

Archived from groups: rec.audio.pro (More info?)

In article <31nrhfF3bb5igU1@individual.net> philallison@tpg.com.au writes:

> ** The signal output from a microphone depends only on the actual sound
> pressure variations that are happening in the air where it is located. It
> makes no difference that the same mic may be connected to a PA or SR system.

Electrically, you're correct as usual. However in practice it makes a
difference. For sound reinforcement, you want to minimize the amount
of room ambience that gets into the mic (or more accurately for your
benefit, what comes out of the mic) because you don't want to amplify
the room for the live listeners. However, for recording (and
presumably later playback in an environment other than the space in
which the recording was made), you want to record that ambience for
later reproduction to the listener.

Different applications mean different mike placement and choice.



--
I'm really Mike Rivers (mrivers@d-and-d.com)
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo
Anonymous
December 8, 2004 10:15:49 PM

Archived from groups: rec.audio.pro (More info?)

Phil Allison wrote:

> ** The signal output from a microphone depends only on the actual sound
> pressure variations that are happening in the air where it is located. It
> makes no difference that the same mic may be connected to a PA or SR system.
>
> If in doubt - read the first sentence again.

Idiot. It makes a considerable difference whether it is
open loop or in a SR feedback loop.

Arny, it wasn't clear to me whether yours was in the loop or
passive.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein
Anonymous
December 8, 2004 10:15:50 PM

Archived from groups: rec.audio.pro (More info?)

"Mike Rivers" <mrivers@d-and-d.com> wrote in message
news:znr1102506790k@trad
> In article <31nrhfF3bb5igU1@individual.net> philallison@tpg.com.au
> writes:
>
>> ** The signal output from a microphone depends only on the actual
>> sound pressure variations that are happening in the air where it is
>> located. It makes no difference that the same mic may be connected
>> to a PA or SR system.
>
> Electrically, you're correct as usual. However in practice it makes a
> difference.

Or at least, it can make a difference.

>For sound reinforcement, you want to minimize the amount
> of room ambience that gets into the mic (or more accurately for your
> benefit, what comes out of the mic) because you don't want to amplify
> the room for the live listeners.

In the case of the room in question - I wish! I can't believe how much room
comes through mics that have lipstick stains on their foamies.

> However, for recording (and
> presumably later playback in an environment other than the space in
> which the recording was made), you want to record that ambience for
> later reproduction to the listener.

The obvious dodge - pick that up with a separate set of mics.

> Different applications mean different mike placement and choice.

Well, its true that for recording voice in a dead studio, you can have
people sing with the mics feet away, not inches.
Anonymous
December 8, 2004 10:15:50 PM

Archived from groups: rec.audio.pro (More info?)

"Phil Allison" <philallison@tpg.com.au> wrote in message
news:31oikvF3ctkdvU1@individual.net

> The signal output from a microphone depends only on the actual sound
> pressure variations that are happening in the air where it is
> located. It makes no difference that the same mic may be connected
> to a PA or SR system.

Agreed, but we have to give the Devil his due.

The SR system is pumping buckets of audio into the room, and if our mics
are sensitive to the larger sound field in the room, the SR system ends up
in the recording. Not always a debilitating problem, but a real
consideration.
Anonymous
December 8, 2004 10:15:50 PM

Archived from groups: rec.audio.pro (More info?)

x-no archive: yes

rick hollett wrote:

> Who pissed in your cornflakes this morning?

He did; he does that every morning.

--
ha
Anonymous
December 8, 2004 10:15:50 PM

Archived from groups: rec.audio.pro (More info?)

"rick hollett" <rhollett@nl.rogers.com> wrote in message
news:cp796l$r33$1@nntp-stjh-01-01.rogers.nf.net

>Ambience from a SR pickup
> will wash out the recorded sound, whereas separate mics for the
> recording will not. No one is saying you're wrong, just a little
> arseholish


The SR pickup is the same as the pickup by a similar mic in a similar
location in the room. IOW, put a SR mic right next to a recording mic in the
same room, and they pick up the same sound field. Exactly identical mics,
exactly idential location, and there will be an exactly identical output
from the mic.

So, if you are claiming that a recording mic will pick up something
different from a SR mic is just plain wrong. They will pick up the same
thing if in they are in the same location and if they are identical mics.
Different locations and/or different mics would be a matter of failing to
compare apples to apples.

If you want to pick up something different in a room, you need a different
mic and/or a different location. Doesn't matter what the mics are attached
to.

Now there's another issue, and that is whether having a SR system going in
the same room as you are recording in, will affect the recording. That
entirely depends on the room and the where the mic is with respect to the
sound source and the speaker(s) for the SR system. It will happen to some
degree ranging from vanishing to profound.

An ideal mic in a SR system will be out of the sound field of the SR system.
Or, the mic will so much closer to the sound source that the direct sound
from the sound source will overwhelm the sound from the SR system. This
then leaves you with a recording that is very dry. The circumvention for the
dryness problem is to record some ambient sound from the room to selectively
mix back in to make the recording.

Well, that is how things work when they go well. You don't get the best
recording in the world, but the results are fairly palatable. This time, in
my opinion, the palatability was a lot less than I expected and I'm trying
to figure out why.
Anonymous
December 8, 2004 10:15:50 PM

Archived from groups: rec.audio.pro (More info?)

"Bob Cain" <arcane@arcanemethods.com> wrote in message
news:cp7tg602f13@enews4.newsguy.com

> It makes a considerable difference whether it is
> open loop or in a SR feedback loop.

Not if the two mics are in the same sound field.

> Arny, it wasn't clear to me whether yours was in the loop or passive.

All that matters is whether or not there was an acoustical loop of sorts in
the room. If the loop is present and the mic picks up the sound field in the
room, and there is a loop that is apparent in the sound field, then the
output of the mic will be affected by the loop. Doesn't matter what the mic
is attached to.

Looking at the recording, and listening to it, there is evidence of an
acoustical loop of sorts, but it was damped. The distance from the mics to
the speaker cluster is about 75 feet (I've said 80 feet before but that is
really the distance to something that is about 5 feet behind and below the
speaker cluster). So this acoustical loop has a periodicity of about 70
mSec.
Anonymous
December 8, 2004 10:15:51 PM

Archived from groups: rec.audio.pro (More info?)

Ha, that explains it.

Rick
"hank alrich" <walkinay@thegrid.net> wrote in message
news:1gogv81.l5u9gaqqla41N%walkinay@thegrid.net...
> x-no archive: yes
>
> rick hollett wrote:
>
>> Who pissed in your cornflakes this morning?
>
> He did; he does that every morning.
>
> --
> ha
Anonymous
December 9, 2004 2:48:07 AM

Archived from groups: rec.audio.pro (More info?)

Arny Krueger wrote:

>>Either the mics are in the SR loop or not. If you are
>>having feedback they are in the SR/PA loop for sure.
>
>
> A properly-operating SR system lacks feedack. Switching the mics from
> omnis to cardioids allowed more gain before feedback.

If the recording mics are in the SR loop, feedback has an
effect. You don't need to get to oscillation for it to be
signifigant and it can be destructive as well as constructive.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein
Anonymous
December 9, 2004 2:51:50 AM

Archived from groups: rec.audio.pro (More info?)

Arny Krueger wrote:
> "Bob Cain" <arcane@arcanemethods.com> wrote in message
> news:cp7tg602f13@enews4.newsguy.com
>
>
>> It makes a considerable difference whether it is
>>open loop or in a SR feedback loop.
>
>
> Not if the two mics are in the same sound field.

What two mics? The question is simply whether the recording
mic is in the SR loop. Does what the recording mic picks up
end up going back out the speakers? If so the feedback
enters the transfer function of the recording, if not it
doesn't.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein
Anonymous
December 9, 2004 5:11:22 AM

Archived from groups: rec.audio.pro (More info?)

"Arny Krueger"
> "Phil Allison
>
>> The signal output from a microphone depends only on the actual sound
>> pressure variations that are happening in the air where it is
>> located. It makes no difference that the same mic may be connected
>> to a PA or SR system.
>
> Agreed, but we have to give the Devil his due.
>
> The SR system is pumping buckets of audio into the room, and if our mics
> are sensitive to the larger sound field in the room, the SR system ends up
> in the recording. Not always a debilitating problem, but a real
> consideration.
>


** My post was in a context Arny - why did you shift it out ??

Was it so you could pretend it was wrong ??






............. Phil
Anonymous
December 9, 2004 5:11:23 AM

Archived from groups: rec.audio.pro (More info?)

"Phil Allison" <philallison@tpg.com.au> wrote in message
news:31ojsmF3chkh9U1@individual.net
> "Arny Krueger"
>> "Phil Allison
>>
>>> The signal output from a microphone depends only on the actual sound
>>> pressure variations that are happening in the air where it is
>>> located. It makes no difference that the same mic may be connected
>>> to a PA or SR system.
>>
>> Agreed, but we have to give the Devil his due.
>>
>> The SR system is pumping buckets of audio into the room, and if our
>> mics are sensitive to the larger sound field in the room, the SR
>> system ends up in the recording. Not always a debilitating problem,
>> but a real consideration.
>>
>
>
> ** My post was in a context Arny - why did you shift it out ??
>
> Was it so you could pretend it was wrong ??

Phil, what's unclear about the word agreed?
Anonymous
December 9, 2004 5:46:04 AM

Archived from groups: rec.audio.pro (More info?)

"Arny Krueger"
> "Phil Allison"

>>>> The signal output from a microphone depends only on the actual sound
>>>> pressure variations that are happening in the air where it is
>>>> located. It makes no difference that the same mic may be connected
>>>> to a PA or SR system.
>>>
>>> Agreed, but we have to give the Devil his due.
>>>
>>> The SR system is pumping buckets of audio into the room, and if our
>>> mics are sensitive to the larger sound field in the room, the SR
>>> system ends up in the recording. Not always a debilitating problem,
>>> but a real consideration.
>>>
>>
>>
>> ** My post was in a context Arny - why did you shift it out ??
>>
>> Was it so you could pretend it was wrong ??
>
>
> Phil, what's unclear about the word agreed?



** The complete contradiction of actual agreement that you posted as a
follow up - you prick.

Read the context - then my comment.

Keep doing this until you see it pure fact and that HA was wrong.





............. Phil
Anonymous
December 9, 2004 10:13:03 AM

Archived from groups: rec.audio.pro (More info?)

Arny Krueger <arnyk@hotpop.com> wrote:

> Actually, we set the gig up with omnis, and backed off to broad cardioids,
> because of the feedback (SR) issues.

why do you need SR on a choir in an ordinary church (450 seats)?

Lars


--
lars farm // http://www.farm.se
lars is also a mail-account on the server farm.se
Anonymous
December 9, 2004 10:50:08 AM

Archived from groups: rec.audio.pro (More info?)

"Bob Cain" <arcane@arcanemethods.com> wrote in message
news:cp8vvg01867@enews3.newsguy.com
> Arny Krueger wrote:
>
>>> Either the mics are in the SR loop or not. If you are
>>> having feedback they are in the SR/PA loop for sure.
>>
>>
>> A properly-operating SR system lacks feedack. Switching the mics
>> from omnis to cardioids allowed more gain before feedback.
>
> If the recording mics are in the SR loop, feedback has an
> effect.

My point is that feedback has the same effect whether a mic is inside or
outside the loop.

What the mic outputs depends on where it is, not what it's hooked to. That's
the cosmic meaning of a low impedance source driving a high impedance load.
Engineering theory isn't changed by the fact that this is SR or recording.

>You don't need to get to oscillation for it to be
> significant and it can be destructive as well as constructive.

Agreed. Trust me, I know a little something about what feedback looks like
in a recording. I've been recording this room for about two years. In that
time (about 100 gigs) I've inadvertently created a wide variety of feedback
situations that lasted at least long enough to measure precisely.

I'm under pressure to run loud, and the room has only limited stability
because the usable part of the stage is almost directly under the speaker
cluster. So, putting the choir 80 feet away from the cluster and in a blind
spot seemed like it would be a real treat.

I've taken many multitrack recordings apart, mic by mic in both the time and
frequency domains.

Some details of the reverb tail tell the tale.

http://www.pcavtech.com/test_data/heard_about.mp3

Look at the depth of the valleys between the amplitude peaks from the last
note. Their depth and the absence of spectral spiking characteristic of
acoustic feedback is very significant to me. If a room is singing or on the
verge, there will be one or more spectral spikes, and the valleys in the
reverb tail will tend to be filled-in.

This recording is very interesting to me, because a number of the room's
problems were circumvented by putting the choir at the opposite end from the
speaker cluster. Not only was the choir far away from the speaker cluster,
they were also well out of its sound field. That's two good things, right?
The third good thing was the fact that they were only a few feet from a
major sound reflector in the room, the back wall. Near reflections in
moderation are better than equally strong very far reflections. Finally, the
choir were relatively close to the ceiling (usually they are over 20 feet
away from the ceiling), for an acoustical shell effect that gives a tighter
sound. This works with the modern, choppy music.

But here's the rub - even with all those good things happening, the
recording has this disturbing harshness that seems to be closely tied to the
singing, in the time domain. That means to me that whatever the problem is,
it started out close to the singers.
Anonymous
December 9, 2004 10:58:05 AM

Archived from groups: rec.audio.pro (More info?)

"Bob Cain" <arcane@arcanemethods.com> wrote in message
news:cp906f11867@enews3.newsguy.com
> Arny Krueger wrote:
>> "Bob Cain" <arcane@arcanemethods.com> wrote in message
>> news:cp7tg602f13@enews4.newsguy.com
>>
>>
>>> It makes a considerable difference whether it is
>>> open loop or in a SR feedback loop.
>>
>>
>> Not if the two mics are in the same sound field.
>
> What two mics?

Two mics, one in the SR feedback loop, and one just hooked to a recorder.

> The question is simply whether the recording mic is in the SR loop.

Doesn't matter.

> Does what the recording mic picks up end up going back out the speakers?

Doesn't matter. As long as any mic in the room is causing feedback, every
mic in the room that is in the sound field of the speakers will pick up the
feedback. Theory and practice meet in my recordings of such events. In fact
I diagnose just about every feedback problem using the choir mics, which are
only rarely actually used for SR. The rest of the time they are muted from
the mains and every monitor in the room. Nevertheless, if the room is
singing the choir mics tell the story.

It's actually a little tricky to figure out which mic is causing the system
to sing if you have a number of mics open. Think about it. You have a bunch
of mics with different amounts of acoustical gain. You have a recording of
each one, taken individually. Which one is causing the feedback problems?

> If so the feedback enters the transfer function of the recording, if not
> it
> doesn't.

As long as a mic picks up the sound field of the SR system in the room, any
recording made from it will include the sound of the feedback. The levels
will vary from mic to mic. Feedback tones are relatively pure unless the
feedback gets so loud you clip the amps or *something else* in the system.
!