The
Grado SR80 is a superb full size open back headphone. I'm not sure they could really be described as neutral. I would describe them more as an 'energetic' headphone!
I have to say I'm a big fan of Grado headphones. I either listen with an iGrado, a Sleek Audio SA6 or a UE Super.fi 5 Pro on my walk to/from work and the Grado's get chosen 80% of the time. To be honest I love the way the entire Grado range sounds, right up to the beautiful sounding
Grado GS1000. While Grado's are not to everyone's liking I feel that they do an excellent job of bringing music alive and make listening really enjoyable.
The
Sennheiser HD595 is much more neutral and is a popular choice. You also get the good Sennheiser build quality.
If you are really looking for a neutral HiFi headphone then the
Audio-Technica ATH-AD700 is an excellent choice. They offer a very clean delivery with an excellent level of clarity in the mids/highs. The AD700 is very good value for money, is very well engineered and sounds better than many much more expensive HiFi headphones.