Hey,

I am looking for a great ambient microphone for background, not just a boom mic. Anyone here know of a good one for under $500.

Thanks!
Thinkingman

have a look at RODE microphones, they seem to be great value at the moment, you are probably after a condenser mic.

I'm a strong believer in getting as much bang for your buck as possible, and, you can do a lot for way less than $500.

Check out this deal on MXL 990/991 condensers: http://www.musiciansfriend.com/srs7/g=live/s=mics/searc...166/?c_tid=topseller

Two mics, both pro grade, and only $99 for the pair. They're best used together too; you can get a Behringer mixer for about $60 that has two mic inputs. With good mic placement, a condenser will capture a bigger field than your ears can even hear, which is great for ambience. I recorded some forest noise for a game project with these, and got some very impressive results.

However if you wanna do field recording in the middle of nowhere (ie. with no power supply), you won't be able to use condensers; they generally require a 48V charge to work, so they need to be plugged into a mixer or preamp of some kind. If you gotta be out there, you'll need to look into dynamic mics. My main recommendation for buying is that the old workhorses (AKG, Shure) are perhaps more trusted, but also several times more expensive; new brands like Behringer are coming out with shockingly high quality and reasonably priced alternatives. And if you want a good deal, pick out your mic of choice from talking to film sound people, but then buy that mic online from somewhere that caters to the not-so-well-endowed musician (like musiciansfriend.com). With so many musical home studios popping up, you're guaranteed to get a better deal than somewhere that sells to film pros.

Good luck!

a lot of condensers are batery powered.

I forgot to ask, is there a particular mic that is good at picking up BG noise (ex. dance club, bar or arena/stage)?

Once you start purposefully recording background noise, it's no longer background noise, it's ambience. Therefore, any unidirectional mic will do, i.e. not a shotgun, unless the shotgun mic has a wider pattern option like a switch. There's no known good tried-and-true "background noise" microphone.

I think I'll try a styrofoam cup and stick some inverted headphones turned into microphones in the center. I'll let you know if it works. j/k