K47 versus K67 Frequency Response Graphs

[Melodeath00]

Through years of research, I've read over and over about how the K67 has a HF peak compared to a K47, and maybe less bass. However, I don't think I've ever seen a frequency plot that compared the two different capsule designs. Does anybody have one? I'm shocked I haven't been able to find anything on google. I've seen lots of graphs comparing one K47 design versus another, or even different CK12-type capsules against one another, but never a direct comparison between K47 and K67. Thanks

 

[Matador]

Recording Hacks has a nice database of these capsule types:  you will often find links to frequency response plots from their respective web pages.

I think Microphone-Parts has a good plot (I hope they don't mind the hot-linking):

With the K67-type in red and the K47-type in black.  You can see the midband rise on the K47-type is in the 2K to 5K range, and for the K67 type (uncompensated), the rise starts in the 7-8K range and peaks after 10K.  This is why the U87-feedback deemphasis starts at about 7K.  You will also see a slight difference down below 200Hz.

 

[Melodeath00]

Hi Matador, I have indeed seen that graph before. However, I noticed it's comparing the microphone parts K47 with a stock chinese 32mm K67 capsule (I assume the MXL capsule is 32mm, but I am not positive). I wonder what differences there are with a true K67 34mm capsule.

One of the reasons I'm asking is in determining differences between the U47 I just built and my Manley Reference Cardioid (which has a k67 capsule). The difference between the mics at 10kHz and above is obvious to my ears, but I'm not sure my U47 has a mid-range rise like that graph compared to the Manley.

 

[RuudNL]

I would be very interested in this too!
In my opinion it is not fair to compare a 'real' K47 capsule to a 'K67-like' (Chinese?) capsule.
So this graph doesn't tell me very much...

 

[bockaudio]

A horrible graph but makes the point. There are other differences, too, like sensitivity and off axis, which are actually important.
ALSO not every K47 (or K67) is the same, though they do each live in their own general class. Many production versions over the years (and that's not including aging).

 

[Melodeath00]

If that graph is more or less correct, does that mean I should be concerned my U47 does not feature that 4k-5k bump compared to my Manley Reference?