I have asked Josephson to comment on the issue and have recieved this reply and josephson kindly agreed to allow me to post the response here. I will also ask Gefell to comment. Both companies have been extreemly helpful with customer support so am gratful for their help and support.
My Question :- Thanks again for the info so far. I wanted to try to find out more about the various phase comments about the mk221 capsuel, I've read, in so far as I can, the comments via the various web sites. is there any technical data about phase response available ? Im not that concerned about it but would like some more info if possible.
Kelly Kay from Josephson :-
The rate at which these phase changes "wrap", that is how gradual the changes are relative to frequency change, is directly related to the damping inherent to the resonance. In order to make any sort of reasonable, useful, directional or omni dc-biased condenser mic internal mechanical and acoustic damping must be *very* high so these phase wraps will be inherently very uniform and very gradual. If the damping were not very high you would instead have very high, audible, resonance related response (presence) peaks as well and an audible objectionable ringing.
Given the above, if you consider the phase wraps one sees when comparing the phase of a "source" of a signal to the signal after it has propagated over a distance...phase relative to the source wraps at increasing rates with increases in distance from the source. It is no surprise that much of the psycho-acoustic research done on the human ability to detect phase variations in recording playback shows that the human ears ability to perceive and differentiate real from artificial is dependant not on absolute flat phase response but instead on smooth and uniform variation in phase response (which absolute flat phase response is a sub set of.) (Note: in the extreme case of comparing compression to rarefaction, in-phase vs. full 180 degree out of phase, it has been shown that a limited number of very good listeners can tell the difference can tell the difference but even then only on something like a strong isolated kick drum sound.)
Sorry, I don't have any references on hand, but a large amount of the foundational psycho-acoustic research into the impact of phase response was published in the AES journal about 20 years ago. The motivation was typically interest in gaining an understanding of criteria required for "accurate" loudspeaker playback however there has been no question as to the fact this should apply to all of the playback chain. So, you may in actually have several of these phase wrap frequencies in your loudspeaker playback (3 if you have 3-way monitors)? the wraps just need to be very gradual over a wider range of frequency (like a slope) and not narrow range (like a step ? which would inherently be tied to a strong resonant ringing.)
Given that, some low-end microphone manufacturers do use questionable resonator structures in their capsule design (intentionally and not), which may in fact cause audible phase related artifacts however, I assure you that is not the case with the well designed MK221.
Also, directional microphones inherently have much more ?trouble? with resonance in the audible range. So, if having a 14Khz diaphragm resonance is considered a problem solely based on its statistic, then directional microphones... particularly the more directional ones (Hyper Cardioid and Bi-directional) should by comparison be quite unusable.
The diaphragm resonance and what the designer both allows it to do and trys to prevent it from doing by making a well though out decision regarding *all* the trade offs is only a single contributor amongst vary many that make up the sound of any capsule?. Then there is the matter of the electronics after that!
Ill ask gefell to comment also and if they will be agreeable to posting a response here.
Dave Blackham
UK