Neumann km 84 new and old

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

DSatz@msn.com (David Satz) wrote in message news:<e6a68193.0410271649.732c10d9@posting.google.com>...
> This is an attempt to attach a new posting to a thread from about two
> years ago, to correct something which I've since learned is in error.
> In case the message doesn't attach itself to the old thread, here's
> the context--I had written this:
>
> "The KM 84, 140 and 184 all use the same K 84 capsule. However, the
> hemispherical reflector behind the backplate and the side vents is
> shaped differently on the newer models. This causes a high-frequency
> response peak of 3 dB or so around 9 kHz, as compared with the more
> nearly flat on axis KM 84."
>
> The response of the KM 84 also had a very slight (maybe 1 dB) bump rather
> than being absolutely flat at high frequencies, and the difference between
> the KM 84 and the newer mikes is really only 1 - 2 dB. But the increased
> bump in the KM 140 and KM 184, according to Martin Schneider of Neumann,
> is due rather to the narrower slits in the capsule housing, which expose
> the rear ports of the capsule.
>
> For his message on the Neumann Pinboard see: http://tinyurl.com/6qqgx
>
> --best regards

As to the sensitivity issues between the U87A and AI models, the
circuits are very similar in the amplifier. The gain is set the same.
The difference in output between them is the older 87 dribbled off the
phantom power to polarize the capsule at around 42 volts. The AI uses
an oscillator to generate 62 volts for polarization bias. Hence the
increase in output level. Unfortunatly, the increased level out of the
capsule will make the amplifier clip earlier as it's gain was not
lowered to accommodate for it.

Newer 87's do have increased "reach" which is important for distant
micing. It uses a capacitor for the pad as many do, the losses in HF
sensitivity when the internal pad is engaged can be overcome by the
use of premium polypropylene film caps rated at 1k volts or higher.

Jim Williams
Audio Upgrades

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

Unless I am mistaken, Martin Schneider also suggests the overall frequency
response of the KM140 and KM184 is virtually identical to that of the KM84
and attributes the newer microphones' perceived brightness as the result of
quieter and cleaner electronics. He further states the electronics of the
184 are slightly cleaner than those of the 140, possibly accounting for
comments we have read from this group that the 184 is brighter sounding than
the 140. He claims the acoustic measurements of each are identical.

Comments?

"Uncle Russ" Reinberg

WESTLAKE PUBLISHING COMPANY
www.finescalerr.com
WESTLAKE RECORDS
www.westlakerecords.com

"David Satz" <DSatz@msn.com> wrote in message
news:e6a68193.0410271649.732c10d9@posting.google.com...
> This is an attempt to attach a new posting to a thread from about two
> years ago, to correct something which I've since learned is in error.
> In case the message doesn't attach itself to the old thread, here's
> the context--I had written this:
>
> "The KM 84, 140 and 184 all use the same K 84 capsule. However, the
> hemispherical reflector behind the backplate and the side vents is
> shaped differently on the newer models. This causes a high-frequency
> response peak of 3 dB or so around 9 kHz, as compared with the more
> nearly flat on axis KM 84."
>
> The response of the KM 84 also had a very slight (maybe 1 dB) bump rather
> than being absolutely flat at high frequencies, and the difference between
> the KM 84 and the newer mikes is really only 1 - 2 dB. But the increased
> bump in the KM 140 and KM 184, according to Martin Schneider of Neumann,
> is due rather to the narrower slits in the capsule housing, which expose
> the rear ports of the capsule.
>
> For his message on the Neumann Pinboard see: http://tinyurl.com/6qqgx
>
> --best regards

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

On Fri, 29 Oct 2004 04:03:38 -0400, Uncle Russ wrote
(in article <qLGdnWipGYTMZBzcRVn-1Q@adelphia.com> ):

> Unless I am mistaken, Martin Schneider also suggests the overall frequency
> response of the KM140 and KM184 is virtually identical to that of the KM84
> and attributes the newer microphones' perceived brightness as the result of
> quieter and cleaner electronics. He further states the electronics of the
> 184 are slightly cleaner than those of the 140, possibly accounting for
> comments we have read from this group that the 184 is brighter sounding than
> the 140. He claims the acoustic measurements of each are identical.
>
> Comments?
>
> "Uncle Russ" Reinberg

That's not the way I hear it. I believe even Karl mentioned they sounded
different. Karl.......

Regards,

Ty Ford

BTW, I had a KM 184 and two KM 84 here a while back and the KM 84 didn't
sound alike. They were of different ages and who knows what background. One
was smooth. The other was brighter, but not quite as bright as the KM 184.



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

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

DSatz@msn.com (David Satz) wrote in message news:<e6a68193.0410271649.732c10d9@posting.google.com>...
> This is an attempt to attach a new posting to a thread from about two
> years ago, to correct something which I've since learned is in error.
> In case the message doesn't attach itself to the old thread, here's
> the context--I had written this:
>
> "The KM 84, 140 and 184 all use the same K 84 capsule. However, the
> hemispherical reflector behind the backplate and the side vents is
> shaped differently on the newer models. This causes a high-frequency
> response peak of 3 dB or so around 9 kHz, as compared with the more
> nearly flat on axis KM 84."
>


So does this mean i can use KM84/KM184 capsules for my KM85 mics?
Which I might be able to buy new?

If the High Pass Filter on the KM85 part of the amp section or in
capsule?

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

Ty Ford wrote:

> That's not the way I hear it. I believe even Karl mentioned they sounded
> different. Karl.......

See, for example, http://tinyurl.com/69a6b -- Karl said that he hears the
KM 140 as sounding the same as the KM 184 (which they are intended to do)
but definitely not the same as the KM 84 (which it isn't intended to be).

Karl is also polite toward those who claim to hear differences between
the KM 140 and KM 184. He allows for the possibility that someone might
hear a difference; two microphones of the same model can sound different
for any number of reasons, and to tell someone that they don't really
hear what they think they hear (especially when he isn't there to listen
for himself) could be insulting. So Karl didn't do that; good on him.

Keep in mind that the electronics of the KM 184 were revised at one point
maybe about three years ago now, but originally the output circuits were
completely identical, and the only difference was at the capsule/amplifier
junction. Now there are somewhat greater differences between the KM 140
and KM 184 amplifiers than there were originally--enough so that they now
carry different dynamic range specifications.

--best regards

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

Ty Ford <tyreeford@comcast.net> wrote:
> On Fri, 29 Oct 2004 04:03:38 -0400, Uncle Russ wrote
> (in article <qLGdnWipGYTMZBzcRVn-1Q@adelphia.com> ):

>> Unless I am mistaken, Martin Schneider also suggests the overall frequency
>> response of the KM140 and KM184 is virtually identical to that of the KM84
>> and attributes the newer microphones' perceived brightness as the result of
>> quieter and cleaner electronics. He further states the electronics of the
>> 184 are slightly cleaner than those of the 140, possibly accounting for
>> comments we have read from this group that the 184 is brighter sounding than
>> the 140. He claims the acoustic measurements of each are identical.
>>
>> Comments?
>>
>> "Uncle Russ" Reinberg

> That's not the way I hear it. I believe even Karl mentioned they sounded
> different. Karl.......

I would expect the KM184 to sound better than the KM140 if there were a
difference due to having one less electric coupling. In the AKG 451/C60
series this is a significant issue, but then they have the added problem
of using the chassis as a signal ground path.

The only other factor in any perceived difference would have to be
mechanical. Perhaps having two "chambers" as opposed to one could
lead to this difference.

Rob R.

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

David Satz <DSatz@msn.com> wrote:
> Rob Reedijk wrote:

>> I would expect the KM184 to sound better than the KM140 if there were
>> a difference due to having one less electric coupling. In the AKG
>> 451/C60 series this is a significant issue, but then they have the
>> added problem of using the chassis as a signal ground path.

> Rob, anyone is welcome to speculate on what could have made one model
> of microphone sound different from a nearly identical design using the
> identical capsule. But it seems moot now that the KM 184 has been
> revised to use different ICs in its output circuit, its noise power
> has been reduced by half, and a similar change has not been made in
> the KM 100 series amplifiers.

> Under certain conditions, two microphones of the _same_ model can sound
> different enough to tell them apart. Because of that, some people prefer
> matched pairs of microphones for certain applications. For those few
> people here who feel that the KM 184 and the KM 140 sounded different a
> couple of years ago, the possibility of individual sample differences
> really can't be ruled out unless those people listened to, say, twenty
> different samples of each model--from different batches representative
> of Neumann's cumulative production for both models--and were still able
> to identify the sound of one or the other model (e.g. an A/B/X test).

> Since that isn't bloody likely, I take their observations at face value.

> I would never say to a serious, experienced professional audio engineer
> that he isn't hearing what he believes he is hearing, unless I can give
> a clear, convincing reason for a misperception to be occurring. There
> could be any number of valid explanations for audible differences.

> Also I am a fallible human being, and it seems appropriate to respect
> the other people who contribute here and give them the benefit of every
> reasonable doubt. That way I might learn something, too--and that would
> justify the time that I spend on forums such as this one.

I want to add that not everyone prefers the KM140. I actually know
a local classical music recording engineer who prefers the KM184.
I am pretty sure he is comparing the KM184 before the revision. And
he has spent a lot of time with both mics.

I still think that resonance of the bodies might be a factor.

Rob R.