Fra InnerFidelity:
HiFiMAN HE-500
Description - These are full size, open, planar magnetic headphones one step down from top of the HiFiMAN line.
Pink Noise - Slightly lacking in bass extension, with mild warmth due to slightly reduced treble. Treble, however, has mildly pronounced narrow peak in mid-treble ("sss").
Bass Texture/Extension - Extraordinary texture and very good extension. Very, very articulate, maybe slightly dry sounding bass ... what ever that means.
Bass Slam - With a very articulate and tight bass, these babies slammed hard. Very nice.
Midrange - These cans deliver really excellent mid-range performance. Extremely natural tonality. But during this test It became apparent that smooth natural highs that didn't draw attention away from the mids, coupled really excellent imaging, adds a sense of realism that provides the synergy with the mids that allow them to be believable. While these cans have a wonderfully neutral and inviting mid-range, they sounded more like a recording than the real thing.
Treble - Though not quite having the last bit of speed that the estats have, the HE-500 has an excellent treble, delivering a very natural rendition of the highs. The slight peak at 10kHz also gives them a bit of sparkle. Very nice.
Dynamics - These do an excellent job of delivering eye-blinking impact without any wincing. The as this testing moves along, I find myself liking these more and more.
Imaging - The well balanced sound here gives both decent depth and space, but lack of speed prevents them from achieving the level of performance of the estats and HD800. Still, a good show here from the least expensive headphone of the group.
HiFiMAN HE-6
Description - These are full size, open, planar magnetic headphones at the top of the HiFiMAN line.
Pink Noise - Very even through bass and mids; slightly uneven and overall slightly accentuated treble with a moderate low to mid-treble peak (think: "shhh").
Bass Texture/Extension - Very good in both texture and extension with slight bloom to sound.
Bass Slam - Planar magnetic cans typically have the best bass as a class of all headphone types. I found the HE-6 to do quite well in bass slam, but the slight bloom and strong treble to somewhat hinder their ability to hit the low notes hard.
Midrange - I found it a bit difficult to focus on the mids with these cans because of the mildly accentuated treble. The mids are very good, but I couldn't quite get interested with the distraction.
Treble - I find the treble here not only a bit too emphasized, but also having a bit too much "tizz," which obscures the natural sound of cymbals and brushwork.
Dynamics - These are very punchy sounding cans, as planar magnetics tend to be, but unfortunately it seems to me that too much impact is coming from excess treble energy.
Imaging - These deliver a strong sense of space and depth, but image specificity (the ability to separate instruments in space) is not so good. The zazzy highs are simply preventing it.
Sennheiser HD 800
Description - Sennheiser's flagship dynamic headphone is a full-size open design, and uses a ring radiator driver to deliver a more planar wavefront to the ear.
Pink Noise - Very even sounding, but lacks a bit of heft in lowest two octaves, and has mild mid-treble emphasis (between "sss" to "ssh").
Bass Texture - Good texture and extension. Slightly "one note" sounding relative to the planar magnetic cans.
Bass Slam - Dynamics are good on these, but the slightly one-note sound and lack of bass extension has these falling a bit short relative to the planar magnetics.
Midrange - The amazingly good imaging of the HD 800 coupled with an excellent mid-range had these cans delivering a great sense of someone standing in front of me singing. But, like the HE-6, though to a lesser extent, the slightly accentuated treble left me feeling the voices were a bit withdrawn and lacking in organic body. Just a bit dry.
Treble - Though just slightly too elevated, the treble here is extraordinarily fast and coherent. All instruments have well integrated, though slightly emphasized, treble components. These sound nearly as speedy as the estats.
Dynamics - Clean, coherent, and articulate, these deliver excellent impact, without any confusion on complex music. But like the HE-6, only to a significantly lesser extent, the somewhat elevated treble makes them "revealing" at the expense of a comfy-cozy sound. Very precise.
Imaging - Here it is, the moment I've been waiting for, I consider the HD 800 the best imaging headphone in the world ... and not by a small margin. The 800s a simply unmatched in their ability to deliver both depth and pin-point localization of instruments. They are so coherent and nicely damped that it almost feels like you can reach out and touch the players. If only these cans didn't have a bit too much treble energy they'd be my desert island headphone, largely on the basis of being able to convincingly "take you there" with their extraordinary ability to deliver a convincing soundstage. The HD 800 is unmatched in this regard.