The capsule in my 4090 is a 4060 capsule with a flat frequency response correction grill added.. And they epoxied it on Smart little fellas at DPA I think this capsule is subjected to a few more tests then the regular 4060 but its the same capsule. This grill to my knowledge is not available for resale. But I have not contacted DPA to find that out.
Chris
Sure would be nice for them to make those available.
It seems one could shorten a standard grid somewhat more to lessen the boost and make it flat, retaining the ~14khz response and polar pattern. The tough part would be figuring exactly how much to trim it. File it down until it's response matches a 4090 (or other flat 'measurement' mic) I guess. Do you think the metal grill part of the grid has any effect other than protecting the capsule, or is it just the tube length that is effecting the response?
Hey boys and girls, here's a fun experiment to hear this effect in action: fire up your mics and monitor through some closed or in-ear phones (to eliminate potential feedback), then hold the capsule and form a little tube with your hand or fingers. The tube doesn't have to be round. Squeeze the opening down to a tiny hole. By changing the volume inside the 'tube' you can easily hear the exaggerated HF boost and the relationship between the size of the opening (or is it the volume of the tube?) and the frequency of the boost.