OK, the problem is sililance. It's not Rode NTK, and a pop filter won't help. It is true that virtually all mics have frequency response peaks and valleys. If I didn't want that, I'd sing through an ECM8000. The last thing on earth I want for a vocal mic is a neutral sound, and BTW, I sound like shit through a U87. I suppose people pay bizzillions of bucks for a U47 or a B.L.U.E. Cactus because it's neutral, right? I agree with one thing, C414 is a pretty neutral mic as they go, and there's no way I'm going to sing through it.
As I see it, you have 3 options. 1. Sell the NTK. That won't be a problem. Lots of us like it. I do, for some things. Then buy a mic that simply suits your voice better. As long as you stick with known good mics, selling the failures is not too hard, which drops the price of admission. Consider a really good dynamic, such as MD441 or SM7. 2. Change your technique, particularly your diction. You say they are good performances, but they're making your mic hiss. Think about it. I know several singers who can turn sibilance on and off like a switch. It may be the NTK is picking up bad sounds you never even knew you were making, because the mics you were using were not detailed enough to reproduce them. 3. EQ the shit out of your tracks, which will probably require a specialized unit or program, a major league de-esser. I personally advise against this, because I would always rather record one clean honest take that sounds good, and then not mess with it. I think good technique and mic placement beats
electronic tweaking just about every time. Good luck. I don't think NTK sucks, and you probably don't suck either, or you wouldn't care so much. I think you're having a few growing pains coming to terms with the mic. You have to either change the mic or change yourself. The latter is a pain in the ass, but it costs less, and makes you a better recording artist.-Richie