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R/E/P => Klaus Heyne's Mic Lab => Topic started by: BobSchwenkler on August 26, 2011, 02:41:13 PM

Title: KM86 capsule factory matching
Post by: BobSchwenkler on August 26, 2011, 02:41:13 PM
Hi,

I just made a call in to Neumann about replacement KM86 capsules. I inquired about matching fees (in regards to both front/back as well as mic to mic matching, this would be for a pair of mics) and was told by the parts fellow that there is no such thing and that their tight production tolerances eliminate any such need.

He seemed not the most knowledgeable on this particular part and I'm just checking here to verify that what he's telling me is accurate.
Title: Re: KM86 capsule factory matching
Post by: klaus on August 26, 2011, 04:23:13 PM
There has been confirmation of that fact in similar threads and posts on my forum through the years.

Neumann indeed deems its manufacturing tolerances tight enough that in the company's opinion, any additional matching work would not be necessary and/or would be cost-prohibitive.
The "matching" Neumann has offered on and off through the years always related to microphone serial number matching, nothing more.

There was one exception: during the manufacturing period of the brass ring version of the K47/49 capsule (ca. 1960 to 1965) Neumann specified the front side on all capsules designated for installation in their remaining U47, 48 and redesigned M49b/c mics.  The side was chosen as 'front' which most closely matched the nominal capacitance spec of the capsule.
Title: Re: KM86 capsule factory matching
Post by: BobSchwenkler on August 26, 2011, 09:32:06 PM
Apologies for the repetition and thanks for the confirmation.
Title: Re: KM86 capsule factory matching
Post by: jeffstuart on August 27, 2011, 09:53:23 PM
For what it's worth I have two KM86i's---one from 1971 and one from 1979---I'm pretty sure they both have their original capsules. I use them as a pair all of the time---they sound as close to identical as I can hear---they even cancel almost entirely when one is 180 degrees out of phase in a coincident configuration...

-Jeff
Title: Re: KM86 capsule factory matching
Post by: David Satz on August 31, 2011, 08:05:06 PM
Five or six years ago I spoke with Dwight Stevenson (perhaps it's "Stephenson") at Neumann USA about ordering replacement capsules for the KM 86, and he told me that the requirement for pair matching causes an extra surcharge (10 to 15%) to be added to the normal price for a pair of KK 84 capsules. He also told me that regular KK 84 capsules (with full-length pins) were available selected for pair matching at a similar surcharge. And as people who've seen the YouTube video about manufacturing the U 87 will have noticed, the halves of the capsules are selected and matched for exactly the same reason. The USM 69 stereo microphone similarly uses a selected, matched pair of K 67 capsules, which incurs a similar surcharge over the cost of "any two" K 67s if the capsules need replacement.

No manufacturer of condenser microphones has yet been able to manufacture capsules so consistently that they don't require selection and matching for critical applications. To claim otherwise is somewhere between "believing your own marketing" and dishonesty. It's only a question of the application and what the selection criteria are.

If a given type of microphone synthesizes its figure-8 pattern from two cardioids, and if that pattern is to be truly symmetrical, then either the two cardioid capsules must have essentially identical sensitivity at all frequencies that you care about, or else you'd have to build some kind of trimming circuit into the microphone. There ain't no other way.

--best regards
Title: Re: KM86 capsule factory matching
Post by: BobSchwenkler on September 01, 2011, 02:10:17 AM
Is this Dwight S. the same who would currently be Dwight (I think that was his name) in Parts? It was this person who informed me about no matching required.
Title: Re: KM86 capsule factory matching
Post by: klaus on September 01, 2011, 06:16:29 PM
Dwight Stevenson still is and has been the parts manager at Neumann/Sennheiser for many years.

Here is Neumann's response regarding David Satz's information on the issue of capsule selection/matching for Neumann mics:

http://www.neumann.com/forums/view.php?site=neumann&bn=neumann_mictec&key=1315209881


In a second and third response, upon subsequent inquiries:

http://www.neumann.com/forums/view.php?site=neumann&bn=neumann_mictec&key=1315295161

Martin Schneider mentions that indeed matched capsules for any mic type are not offered as a standard service or part, but can be arranged in individual cases and under certain circumstances.

You can however still purchase two matched K67 by ordering a pair of SM69 capsules, if you want to have a matched pair of a U87A or SM69/fet