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Stereo Pairs of Mics

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

I own a km 184 and I want to get another one for various stereo micing
(mostly drum overheads). What makes a stereo pair? How will it differ from
to individual km 184's positioned properly? Does consecutive serial #'s mean
they are a stereo pair?

Thanks,

Neil R

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

"Neil Rutman" <neilrutman@bigfoot.com> wrote in message
news:VeadnRpR4dZCs6vcRVn-ow@speakeasy.net...
> I own a km 184 and I want to get another one for various stereo micing
> (mostly drum overheads). What makes a stereo pair?

Matched for identical or virtually-identical characteristics... usually at
the factory, but not always.

>How will it differ from to individual km 184's positioned properly?

Maybe a lot, maybe not much - if you get lucky & have two mics that just
happen to be within a certain small percentage of various tolerances with
each other.

>Does consecutive serial #'s mean they are a stereo pair?

Nope, but you have a better chance of lucking out into a useable stereo
pair by using mics with consecutive serial numbers (but happen not to have
been spec'ed out as a matched pair), simply because there's more of a
chance that the various components came from the same manufacturers'
batches & therefore are likely to have less variance than components (and
the resultant mics) that may have come from batches manufactured a year or
two apart from one another.

Having said all that, I've used mics (specifically, pairs of U87's, KM184's
& C414's) that were nowhere near each other in serial number sequence, and
were not a matched stereo pair, and have gotten what I would consider
completely useable stereo imaging with one side hardly discernable from the
other in output, tonal characteristics, and so on. If you're using
high-quality mics from manufacturers that employ more strict quality
controls, then you have a better chance of being able to get away with
this, IMO. Now... having said THAT, I've not done this in any circumstance
where a stereo pair might be the only sound source - I might be more
skeptical of the results in that kind of situation & be more prone to go
with an actual matched pair.
--

Neil Henderson
Saqqara Records
http://www.saqqararecords.com

Reply to Anonymous

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

In article <VeadnRpR4dZCs6vcRVn-ow@speakeasy.net> neilrutman@bigfoot.com writes:

> I own a km 184 and I want to get another one for various stereo micing
> (mostly drum overheads). What makes a stereo pair?

Two microphones with the same frequency response and directional
characteristics. Generally you're safe with two of the same make and
model as long as it's a manufacturer that has reasonable quality
control and the mics that come off the production line all sound
pretty much alike. Neumann is good about this, Guitar Centar Oktava is
bad about this, anything else is anything else.

> How will it differ from
> to individual km 184's positioned properly?

It won't. Two KM184s make a perfectly decent stereo pair

> Does consecutive serial #'s mean they are a stereo pair?

No. It means that someone thinks he can charge more money because of
it. Good quality mics don't have to have consecutively numbered
stickers (which doesn't even mean they were made consecutively) placed
on them in order to indicate that they're matched closely enough to
work for stereo pickup.

Just buy another KM184 and enjoy having two, plus having stereo.

--
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

Reply to Anonymous

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

Any two microphones can be used as a stereo pair.

A matched stereo pair is idealy comprised of two microphones of the same
model that have been hand selected according to their frequency response
curves.
Matched stereo pairs usually cost a little more, though if you aren't picky
then two mics of the same model could okay without matched frequency
response.

Neil Rutman <neilrutman@bigfoot.com> wrote in message
news:VeadnRpR4dZCs6vcRVn-ow@speakeasy.net...
> I own a km 184 and I want to get another one for various stereo micing
> (mostly drum overheads). What makes a stereo pair? How will it differ from
> to individual km 184's positioned properly? Does consecutive serial #'s
mean
> they are a stereo pair?
>
> Thanks,
>
> Neil R
>
>

I have two Octava microphones, relatively inexpensive Russian mics that can
sound pretty good.... or somewhat out of kilter, depending on your luck. I
purchased them as a hand selected pair though and indeed, they sound good!
Much better than the previous pair of Shure SM81s I owned, which may not be
saying much... Anyways, I did have to repair one of them upon arrival, so
I wouldn't necessarily recommend Octava (though I could have returned the
mics for another new pair). That's the only matched pair I've ever had
personally, though I've done sessions at another studio with an unmatched
pair of KM84's that sounded better than my Octavas for sure. Matched mics
are great. Matched cheap mics are great if you're a tech. :-P

Skler

Reply to Anonymous

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

Thanks guys!

"Cerion" <eeeeek@notmail.com> wrote in message
news:ch5rlh$egr$1@geraldo.cc.utexas.edu...
> Any two microphones can be used as a stereo pair.
>
> A matched stereo pair is idealy comprised of two microphones of the same
> model that have been hand selected according to their frequency response
> curves.
> Matched stereo pairs usually cost a little more, though if you aren't
picky
> then two mics of the same model could okay without matched frequency
> response.
>
>
>
> Neil Rutman <neilrutman@bigfoot.com> wrote in message
> news:VeadnRpR4dZCs6vcRVn-ow@speakeasy.net...
> > I own a km 184 and I want to get another one for various stereo micing
> > (mostly drum overheads). What makes a stereo pair? How will it differ
from
> > to individual km 184's positioned properly? Does consecutive serial #'s
> mean
> > they are a stereo pair?
> >
> > Thanks,
> >
> > Neil R
> >
> >
>
>
>
>
> I have two Octava microphones, relatively inexpensive Russian mics that
can
> sound pretty good.... or somewhat out of kilter, depending on your luck. I
> purchased them as a hand selected pair though and indeed, they sound good!
> Much better than the previous pair of Shure SM81s I owned, which may not
be
> saying much... Anyways, I did have to repair one of them upon arrival,
so
> I wouldn't necessarily recommend Octava (though I could have returned the
> mics for another new pair). That's the only matched pair I've ever had
> personally, though I've done sessions at another studio with an unmatched
> pair of KM84's that sounded better than my Octavas for sure. Matched mics
> are great. Matched cheap mics are great if you're a tech. :-P
>
>
> Skler
>
>
>

Reply to Anonymous

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

On Wed, 1 Sep 2004 21:17:18 -0400, Cerion wrote
(in article <ch5rlh$egr$1@geraldo.cc.utexas.edu> ):

> Any two microphones can be used as a stereo pair.
>
> A matched stereo pair is idealy comprised of two microphones of the same
> model that have been hand selected according to their frequency response
> curves.
> Matched stereo pairs usually cost a little more, though if you aren't picky
> then two mics of the same model could okay without matched frequency
> response.
>
>
>
> Neil Rutman <neilrutman@bigfoot.com> wrote in message
> news:VeadnRpR4dZCs6vcRVn-ow@speakeasy.net...
>> I own a km 184 and I want to get another one for various stereo micing
>> (mostly drum overheads). What makes a stereo pair? How will it differ from
>> to individual km 184's positioned properly? Does consecutive serial #'s
> mean
>> they are a stereo pair?
>>
>> Thanks,
>>
>> Neil R

>
> I have two Octava microphones, relatively inexpensive Russian mics that can
> sound pretty good.... or somewhat out of kilter, depending on your luck. I
> purchased them as a hand selected pair though and indeed, they sound good!
> Much better than the previous pair of Shure SM81s I owned, which may not be
> saying much... Anyways, I did have to repair one of them upon arrival, so
> I wouldn't necessarily recommend Octava (though I could have returned the
> mics for another new pair). That's the only matched pair I've ever had
> personally, though I've done sessions at another studio with an unmatched
> pair of KM84's that sounded better than my Octavas for sure. Matched mics
> are great. Matched cheap mics are great if you're a tech. :-P
>
> Skler

OTOH,

When I bought another Schoeps CMC641, they took a look at the individual
frequency response curve they had on file for that mic in Germany and picked
one with as similar a response as possible. Of course, over time and
conditions, the original could have varied, but I thought it was Pretty Cool
that they went to the effort.

Regards,

Ty Ford

-- Ty Ford's equipment reviews, audio samples, rates and other audiocentric
stuff are at www.tyford.com

Reply to Anonymous

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

Neil Rutman wrote:

> I own a km 184 and I want to get another one for various stereo micing
> (mostly drum overheads). What makes a stereo pair? How will it differ
> from [two] individual km 184's positioned properly? Does consecutive
> serial #'s mean they are a stereo pair?

In your application you will probably do very well with any two KM 184s
that are both working properly. People may complain about the rise of
automated production in place of assembly by hand, but one of the big
advantages is the improved consistency of the results, for sure.

Actually in checking over the literature on the KM 180 series, I notice
that the equivalent noise specification was improved by 3 dB at some
point between 2000 and 2002. However, the sensitivity and maximum SPL
are the same as before, and I'm not aware of any change to the capsules.
Certainly for drum overheads, I wouldn't hesitate to mix and match older
KM 184s with newer ones.

Neumann has gone through several phases with regard to pair matching.
Used to be, it was a normal service available on special order at a
slight extra cost. Then for a number of years they sold "stereo pairs"
which had consecutive serial numbers, meanwhile claiming that the
overall consistency of their products made specific pair matching
unnecessary. This was in part because they left it up to their national
distributors in different countries to assemble the pairs, and those
distributors didn't have the test equipment or access to the factory
production records which would allow them to select the best matches.

The problem with that approach is that [a] capsules and amplifiers are
built in separate batches at separate times, and only then are assembled
into complete microphones; [b] the variation among capsules (and the sonic
significance of that variation) is far greater than the variation among
amplifiers, while [c] it is the amplifiers which are serially numbered!
Having two consecutive serial numbers on the amplifiers doesn't even tell
you whether the capsules are from the same batch, let alone whether they're
a good match for each other or not.

More recently they have standardized the stereo sets at the factory, and
those sets have started to include actually selected, matched pairs.

Pair matching is important primarily for main microphones which are used
in coincident or near-coincident stereo pickup methods, particularly if
the signals from those two microphones constitute the entire recording.
For spaced microphones or spot microphones, there is far less need for it.

--best regards

Reply to Anonymous

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

Neil Rutman wrote:

> I own a km 184 and I want to get another one for various stereo micing
> (mostly drum overheads). What makes a stereo pair?

Two reasonably identical mics.

> How will it differ from to individual km 184's positioned properly?

Those will also be a stereo pair. The question is then whether they are
a good stereo pair.

> Does consecutive serial #'s mean they are a stereo pair?

No, they mean that one had its number stamped immediately after the
other, and usually thus also that they are manufactured after each
other. That increases the probability that the variable ingredients
(diaphragm(s)) are similar.

Acoustically mics become a stereo pair by recording the same sound
source. In salesmens lingo they are a stereo pair if the serials are
close and preferably on the same side of a ¨50. In DPA lingo - as I know
it from an old article about the Dead PA in db magazine - they are a
matched pair if their phase differencd at 10 kHz is less than 10
degrees. Notice the significant difference between a stereo pair - it is
about deployment of the mics - and a matched pair, that is the wording
that is about the mics being similar within some defined tolerance.

It can be relevant to use fairly different mics for a stereo pair, an
upright piano is an excellent example.

> Neil R

Kind regards

Peter Larsen

--
*******************************************
* My site is at: http://www.muyiovatki.dk *
*******************************************

Reply to Anonymous

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

Neil Rutman <neilrutman@bigfoot.com> wrote:

>I own a km 184 and I want to get another one for various stereo micing
>(mostly drum overheads). What makes a stereo pair? How will it differ from
>to individual km 184's positioned properly? Does consecutive serial #'s mean
>they are a stereo pair?

The high end microphones (like DPAs) will come with a frequency response
curves and a measurement of sensitivity. When you go to buy a new one,
buy one with a similar frequency curve and sensitivity number.

Sequential numbers don't necessarily mean much, as the serial numbers
may be on the case rather than the capsule, and may go on late in
assembly or before they are packed/shipped rather than when the capsule
and its electronics are assembled and tested.

The best you can hope for is that two same-model mics are within the
tolerances of the manufacturer's specifications.

But strangely, Neumann's KM184 Web page doesn't provide tolerances on
the KM184's specifications, so we have no idea how far apart two
off-the-shelf can be. They could be 6 dB (+/- 3 dB) apart in frequency
response shape and 10 dB (+/- 5 dB) apart on sensitivity and still meet
that page's specs.

Anyone who manufactures mics knows that the frequency curves and polar
patterns that Neumann (and other manufacturers) publishes are idealized
curves. It'd be nice if they published tolerances on the Web so we knew
just how idealized they are.

Digging a bit on the Neumann Web site, the KM180-series brochure shows a
+/- 2dB tolerance on the frequency response curve and no tolerance on
sensitivity. This means that two KM184s taken randomly off-the-shelf
could be as much as 4 dB apart in frequency response curve shape and
God-knows-how-far-apart in sensitivity. This means that it's not very
likely that you'll get two well-matched mics simply by buying two from a
store.

So, if you're interested in a well-matched pair, have your dealer match
two from stock (if they're able) or have them buy a matched pair from
Neumann.

--
Len Moskowitz PDAudio, Binaural Mics, Cables, DPA, M-Audio
Core Sound http://www.stealthmicrophones.com
Teaneck, New Jersey USA http://www.core-sound.com
moskowit@core-sound.com Tel: 201-801-0812, FAX: 201-801-0912

Reply to Anonymous

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

Len Moskowitz wrote:

> But strangely, Neumann's KM184 Web page doesn't provide tolerances on
> the KM184's specifications, so we have no idea how far apart two
> off-the-shelf can be. They could be 6 dB (+/- 3 dB) apart in frequency
> response shape and 10 dB (+/- 5 dB) apart on sensitivity and still meet
> that page's specs.

On the Neumann Pinboard, Martin Schneider of Neumann in Berlin wrote
(and this should be in their message archives if you search for it):

======================================================================

About matching mics: our standard tolerances given in the data sheets are
+/-1dB for sensitivity, and +/-2dB for the over-all frequency response.

A simple sensitivity difference can be regulated with the pre-amplifier
gain, with no further effect (and 0.5...1dB is just the difference the
human ear is able to differentiate). The over-all tolerances could mean,
in the case of the KM140/184, at most a slight difference in very high
frequency response.

But actually our tolerances in production are generally much smaller
than the +/-2dB mentioned. We thus generally say that our capsules
are, as a standard, very well matched, and that there is no need for
further matching. Consecutive serial numbers are, from an aesthetic
point of view, nevertheless an understandably nice thing to have.

======================================================================

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