If you are looking for the best open back on ear headphones with a wire, let me share with you my review of Grado SR225e vs RS2e.
The headphones reproduce a very quality sound with the sensitivity of 100 dB. They have a great compatibility with mobile devices for the impedance of 32 Ohm. The frequency response of Grado SR225e is more narrow vs RS2e with 20Hz-22KHz vs 14Hz-28KHz, but both are quite enough for a good audio reproduction.
The difference of Grado SR225e vs RS2e is that the latter improves the qualities of a broad soundstage, has a stronger and clearer bass, and an excellent resonance. That makes RS2s a great alternative to SR225e. However both models have a clear imaging, a wide open soundstage, and neutral, harmonious sound at all ranges. The bright feature of both headphones models is a clear reproduction of mids that is not put backwards with bright bass and highs. But the sound of Grado SR225e seems to me warmer vs more accurate RS2e that may sound too brassy for sensitive ears while the warm sound of the first model embraces with a smoother sound, even being not so bright.
The wooden ear cups of RS2e look smart and unusual. The model SR225e has plastic cups. Both have soft foam cushions. The cups are very breathable for the open design that does not make my ears sweat. The headband is decently soft and not tight. The cups are not foldable, however, lay flat to take less space or wear on the neck. Unfortunately, the cable is not detachable, that makes them not portable and not safe if it tangles over something.
Both headphones are lightweight, but Grado SR225e vs RS2e is lighter with 280 vs 385 g.
The GRADO RS2e is better headphones in this comparison. Check GRADO RS2e price