Where to Buy in NYC and LA

[P'cisT]

Hey everyone,

Firstly, I'm from Australia, and I am having a little holiday to the States next month. I am looking to buy a nice Pioneer headunit while I am over there.

I would just like some recommendations on where to shop in either New York or Los Angeles. Keep in mind, I have never been there before, and will be staying in the city/downtown, so any place easily accessible from there is good. Even just store names would be good.

Also, for realistic prices, would http://www.crutchfield.com/ give me a good idea?

All input appreciated.