From the archives (thanks, Harvey), I gather that a "good" FR is more about aesthetically matching a mic to the source/room/etc than finding a “holy grail” frequency response shape.
I'm wondering how much the FR graph changes when a mic is fed a complex signal like music, compared to a test...
I was just looking at the bluetube dp, too. The archives have many comments on it:
http://www.google.com/search?q=presonus+bluetube+dp+site%3Ahomerecording.com
also the reviews at the bottom of this page:
http://www.presonus.com/bluetubedp.html
the original bluetube was less liked, often said...
I'm looking for a 2 channel mic preamp / USB interface that can also be used just as a mic preamp, without connection to a computer. It also needs to supply 2 x 48V phantom power.
Basically, I want to record myself (guitar/voice) in my living room onto tape, for me to listen and learn about...