I'm always trying to find the best possible headphone for this. I've found the best for female vocals without a double under $100 (that i've tried) is the Koss Pro DJ 100. This is mainly due to it's very slightly forward upper mids. Next best is the AKG K240 Studio. Maxell DHP-II is also not bad.
For $100-$150 I like the Shure SRH-840, but it's vocals to me aren't any better than the DJ100.
For anyone curious as to what the best past that is, my favorite is the ATH-AD2000 for female vocals. The K702 also isn't too bad, same with the HD-600. K601 is also nice because it's mids are more forward sounding than the K702, but has less detail, a smaller soundstage, but better imaging. W1000 is also supposed to be good, but I haven't heard it yet.
EDIT: I guess I can't read and missed the "open" part. I still think it's worth considering a closed headphone for female vocals. Open headphones for this are rarely as good, with a few exceptions like the K601 and ATH-AD2000.
Quote:
Originally Posted by
Gluegun 
Heya, I've been out of the loop for a while. What are the best relatively efficient, under $100 headphones for really enjoying female vocalists, these days? And is there something REALLY incredibly awesome in the ~$150 range, to be an excuse to trade from the 'normal budget limit' to the 'stretched budget limit'?
If the genre matters, and I don't think it should, opera, singer-songwriter, some jazz inspired, folk, etc, but with a big focus on, of course, female vocalists. I'm thinking of some big old open thing. Buying online is okay, and budget is for 'after shipping', and within the lower 48.