[KeithMoonwannabe]

I don't use an Mbox as I use Reaper and Focusrite Saffire Pro 10 i/o for an interface but typically an A/D converter like the Sparrow would bypass the clock inside the mbox so you should be much better off since the converters in the sparrow are much higher quality.

I would think a Sparrow and a decent mic preamp would be a definite step forward.

But I would suggest before spending the dough on that SM7b or any mic to check into other mics, I always like having my options open, you never know what you'll like best if you never try it out first.

The BLUE bottle rockets are both fantastic mics and would give you a lot of options down the road with interchangeable capsules. The stock capsule is similar to the Bluebird's capsule btw. I just met a BLUE rep when I was shopping the other day. Now I have a pair of Blue balls coming to mike up guitar cabs lol. And I'm pretty sure I found my next item to save up for in the Bottle Rocket Stage 1 (I'd prefer the tube Stage 2 but I'm broke so I have to keep it real).

If you want that fat, mojo vibe check out the Sennheiser dynamics (MD441 and MD421), the Heil PR30 and PR40, Shinybox 46MXL, Beyerdynamic mics, Electro-Voice RE-20 and RE-27.

I was just thinking though the point of the vocal booth is to use any mic and get a better room sound for your vocals, nothing wrong with an SM7b by any means but you could use a mic that picks up the environment in a good booth and get a little more dimension to your sound.