I'm curious, is there actually a huge sonic difference between using a mic that's hyped, with no eq vs using a mic that is primarily flat with eq?
In other words if I took 2 mics such as a ksm32 and a tlm103 and I used a high shelf and bell on the 32 (simulating the 103 curves) and kept the 103 flat would these mics then sound similar? This is hypothetical or course I realize these are 2 different mics and have other differences besides curve.
You can get very close with EQ for the sound that is on axis of the mic, but you can't compensate for off-axis response of the mic.
Of course different mics have different off-axis and transient response and also different distortion characteristics, so some mics take the EQ better than the others.
EQs are always going to introduce something to the signal beyong just the curve. Beyond that, there are always going to be other factos between mics: polar pattern, how they handle proximity and transients, distortions, etc. So I think the answer practically speaking is no; you can EQ a flat mic to have a similar curve (somewhat) but that's certainly not the only factor.
EQ may introduce phase shift. Off-axis response cannot be accounted for. Dynamic response cannot be accounted for. Membrane resonances cannot be accounted for. Distortion characteristics and other non-linearities cannot be accounted for.