I just learned from testing, and three experts on the subject confirmed, that
<s>all</s> at least SOME Oktava microphones are wired with reversed polarity!!!
This polarity inversion results in the signal being 180 degrees out of phase. Pins 2 and 3 are swapped on (at least
some) Oktavas. If you talk into the mic monitoring via headphones, it will sound fuller with the polarity inverted. All other mics in my experience sound fuller via that test with the polarity normal.
This is apparently "by design", since it is consistent, even though afaik no other mic manufacturer does it that way. It doesn't necessarily mean the mics suck, it just means that you should flip the polarity on them via a preamp switch or inverting adapter by default.
Why? Because when an impulse blows air onto the mic capsule, it should translate to the speaker downstream blowing air in the same direction onto the listener's ear. Blowing air shouldn't translate to air being sucked back. I have a Chesky test CD (JD37) that shows just how disappointing a trumpet sounds with the polarity reversed...as if the trumpeter is sucking the air back into the trumpet (the disc is from the 80's and is screwed up in that they also reversed channels L and R, but importing the file into a DAW and properly inverting it yourself demonstrates the issue). This same degradation happens to a lesser extent on any signal. It's actually easy to verify this on a good enough monitoring system with a good enough signal, but many people have yet to realize that.
Scott Dorsey (of the famous "Dorsey MC-012 mod") writes on rec.audio.pro, 10/19/2002:
Quote:
The 219 is pin 3 hot. So are a lot of European microphones. It's fine, don't worry about it.
But I
do worry about it, Scott! And I'm not sure what other mics have this problem. It
is a problem. One that's very easy to fix of course, you just have to remember to do so.
Interestingly, to my knowledge, correcting the polarity isn't a standard part of any of the Oktava mods that are available. I just confirmed that my 219 <s>and four different 012's all</s>
(EDIT: apparently the 012's I tested were actually pin 2 hot) had the polarity reversed. I have to wonder whether Oktava's reputation could have been subtly damaged all these years by this odd reversal. Why are they being made, and left, inverted?