People has been asking me to do a comparison between the Shure SRH-840, the Sennheiser HD25-1, and the Audio Technica ESW-9. For a long time, the ESW-9 and the HD25-1 can be considered two of the most loved portable closed cans. Then, Shure released the SRH-840, and it also started to build a group of followers, me included. The SRH-840 actually is rather big to be called a portable, but somehow, perhaps due to its foldable design, gets discussed in the same category as the HD25-1 and the ESW-9. For me, the comparison is quite valid, as I also use the SRH-840 the same way I used the HD25-1: outdoors.
These three cans are very respected in the headphone community, and each has qualities that appeals to a big group of people. Each headphone, however, have a very distinct sound signature that makes them unique from each other. They are all very good at what they do, and for that reason, I don’t think it would be fair to rank one as better from the other.
The Audio Technica ESW-9 is very unique, in that it sounds like it has a tube amplifier permanently attached to its drivers. Though amplification and source can alter the sound of the ESW-9, at the end, the sound will still come out sounding smooth and tubey. This is one of the biggest reason that people get the ESW-9, to get a tube sound without actually using a tube amplifier. The ESW-9′s strong point is in the midrange, as its tube-like midrange sounds very pleasing, especially when listening to vocals. Another thing that the ESW-9 does well is covering up for mediocre and sibilant recordings.
While the ESW-9 has a strong point for sounding very tube-like, often the tube flavor can be very strong, and being a strongly colored headphone, the sound will not change much despite any changes you do on the amplifier and the source. This can be a double edged sword: it’s great when you really after that tube sound, as you won’t get it from the other headphones, but when you want a more “solid-state” sound, you’re not going to get it with the ESW-9. The ESW-9 is great for RnB and Modern Jazz. However, I wouldn’t recommend it for fast-paced music, as the ESW-9 can sound too relaxed.