These are planar-magnetic, open back headphones and are the flagship in HiFiMan's line. It has great clarity and smoothness on the highs and mids along with punchy, tight and accurate bass which is the strong point of planar magnetic drivers.
These headphones are pretty large and heavy, so these are best for indoor use only.
Pro Highly detailed sound with full mids and controlled bass
Highs are really clear and crisp and are able to present even the slightest details in the music that other high quality headphones are not able to give. These frequencies have a lot of sparkle and airiness to them, yet do not sound too harsh or too forward, preventing these from sounding fatiguing.
The mids are mixed really well with the rest of the frequencies. Slightly forward, the mids can easily be heard and appreciated, so sounds like vocals, guitars and keys are really defined.
The bass of these headphones have good power, but not as much as bass-heavy "bass head" cans. Instead, the bass is natural with good sub-bass presence. Bass thump is definitely there but without the bloat that can muddy up the sound.
Pro Three cables are included
It comes with 3 different headphone cables, with each one terminating in a different connector. This gives you a lot of versatility in terms of the audio sources that you can connect to. They also work well as spare cables should one get damaged.
It comes with a balanced XLR cable, a 6.5mm TRS cable which are best suited for desktop use and a 3.5mm cable for portable devices.
Con Requires a significant burn-in time for optimal sound
The HE1000 V2 requires a pretty long burn-in time of around 200 hours in order to get the best sound out of it. Initially, the highs can be harsh and the bass a bit lean. After burn-in, these issues should not be present anymore.
Con Picky with the amp/DAC you use these with
These require a bit of power to run so you will most likely need to invest in a great amp. Also, you may want to consider going through different DAC options as these headphones are so revealing that you can easily distinguish artifacts or distortion from a lesser performing DAC.
Con Open design leaks out a lot of sound
The sides of these earcups are almost totally open so when you play music through these headphones, they also function like mini speakers as they leak out a lot of sound. These are not the best headphones for you if you share your room with other people as the sound can be distracting.