Sugarite wrote:

This is leading towards a debate over whether two matched cardioids
are in fact a truer match than either side of a fig-8. I'm of the
opinion that the matched card's are a truer match, mostly because you
can't as easily test the internal bipolar matching on a mic-by-mic
basis like matching two card's.

May I take a closer look at this rather mysterious course of logic? If
I didn't know better, I'd think you were saying that the ease of testing
which you imagine in a thought experiment (!) should take precedence over
the accuracy of competent real-world measurements.

But even granting that, I think your logical conclusion would be: "If I
had to document the front/back symmetry myself, I'd prefer two cardioids.
Then I'd have my own way to make the measurements, so I would feel more
comfortable trusting the results." Human to human, I could respect that.

Still, that isn't quite the same as the broad claim that "cardioids match
better than the front and back of a figure 8" (which is what you said).
The two statements are about different things--the first one is about
your own mindset, while the other one is about microphone capsules, no?


It's impossible to test both sides of a fig-8 with that level of
precision. All you can do is "read curves".

If I didn't know better, I'd think you were claiming to know the level
of precision of curves which you've never seen and don't know a thing
about. Also, in this case I can do a bit more than "read curves," since
the ones I described were those of a pair of capsules which I used for
nearly 25 years; I made several hundred live recordings with them. And
I've had even longer experience with frequency response curves from that
particular measurement chamber.

In 1974 I even did some blind testing--I was sent a pair of test capsules
with no indication of their characteristics. I tried them on a recording
and reported back that I had heard a response elevation of 2 dB between
a certain pair of upper midrange frequencies. I was then allowed to see
the response plots; I had estimated them exactly. I don't claim that I
could do that every time, of course. But I feel I do have a real luxury,
which is that I can indeed "read" these curves and, in relation to them,
I also know from long experience what the results sound like.

Given that situation I don't share the dismissive attitude that some
people have toward response plots--I find that they can often tell me
quite a bit about a microphone.

As you may know, ten of the manufacturers in the AES Working Group on
microphone specifications have recently completed a "round robin" test
in which each of them submitted one cardioid microphone which they and
all the other manufacturers measured, so that they could compare notes
on how they measure microphone response and how they present the results.
A paper was presented at the recent Tonmeistertagung in Germany which
described some of the results of this "round robin" test (I was the
translator for that) and I hear that there was also some discussion or
perhaps a paper about this at the most recent AES convention as well.

--best regards