I am an headphone newbie......
Thank you very much.
You need to elaborate more about your expectations, so that you would get the right suggestions.
what genres do you listen? Do you also play games? are you looking for open or closed headphones? what type of sound signature do you want? more bass, all details of instruments? are the headphones for home use or for on the go use?
Did you listen DT 880 250 Ohms from iphone + headphone amp or just iphone only?
Have you checked sennheiser hd 650 and 600, akg q 701?
Do you listen music from computer or a cd player?
greetings from Torino
DT 880 250 Ohm headphones need an amp (such as, Fiio E11 or E12) to get full benefits. This is why the sound quality of DT 880 250 Ohms was not good, when connected directly to the iphone.
Another question, To what device do you plan to connect the new headphone? (computer or cd player or something else)
I bought used HE 400 from sale/trade section of this forum. They are fun sounding headphones.
I have not listened HE 500. I have read that HE 500 is better than HE 400.
What type of sound signature do you want? do you like more bass or do you like to listen all the details of instruments?
If you listen music from a cd player, you need a headphone amp. If you listen music from a computer, you need a dac/amp.
You could consider audio gd 15.32 http://www.head-fi.org/t/648386/audio-gd-nfb-15-32-delivery-impression-thread, http://www.audio-gd.com/Pro/Headphoneamp/NFB1532/NFB15.32EN.htm