Sources: iPhone5 alone, iPhone5 with FiiO E07k using LOD, iPhone5 with v-moda Verza DAC/amp, various computers using the v-moda Verza DAC/amp.
First impressions of the B&O H6: Much better than average soundstage for a closed headphone, very detailed bass that's neither emphasized nor recessed, and mids that have a slight emphasis around ~1 khz to ~2 khz that give the overall signature a lighter sound than most of the headphones I've been listening to for the past few months. Exactly how this signature would compare to the kings of 'Neutral', i.e. the Sennheiser HD600 and HD800, I don't know because I don't have either one handy now, but I'd guess it's very close. For example the somewhat warm ATH ESW9a with the wood cups sounds nearly identical to the H6 when the ESW9a's treble is boosted slightly. The H6 does not have a bright treble by any means - the treble has about the same strength as a classic neutral headphone (see above), and low quality music tracks with excessive sibilants or other such distortions may be irritating with the H6 if played at loud volumes.
My most recent listening has been with the Sol Republic Master Tracks, Beats Mixr, Marshall Monitor, ATH WS99, Soundmagic HP200, Beyer DT770-32LE, v-moda M100, and the ATH ESW9a. With the B&O H6 I'm hearing detail I haven't heard since I had the Shure 1840 or since I last used my Sennheiser IE800 IEM's. I'm hesitant to exaggerate my description of the H6 soundstage, but after playing a few hundred music tracks, I can say with confidence that it's very, very good. I played a series of test tone sweeps with a number of discrete tones as well, and other than noting the very slight emphasis in the upper midrange, everything seems very well balanced. It's easy for me to say that I love this sound, but what's more important is for readers to understand how it might sound to them. This B&O H6 should sound fairly neutral like the aforementioned Sennheisers, with a slight tilt toward a "light" signature that's more or less the opposite of most of the headphones I mentioned above as recent listens.
The one quality of the H6 that I'm most certain of in terms of how prospective customers will relate to it is the bass. The H6 bass is not light like the very pricy Shure 1840, nor does it have an iota of strength above neutral. I find the bass satisfactory on all of my music, which covers nearly all genres, but users who need a little extra kick (for whatever reason) should look elsewhere. Theoretically you should be able to use a bass boost whenever you feel the need, but whereas I've had good results with some headphones with a treble boost or with bass reduction, I've never had a satisfactory experience with bass boost, unless there was a bass boost feature on one of my headphone amps that had a better tone curve than what the Apple i-devices have.
The comments in the music tracks listed in this review can be compared to other headphone reviews I've done, to get an idea of how the H6 plays the different types of music listed here compared to other headphones. Based on my favorable impressions of the H6 with the first series of tracks which are heavy on electronic sounds, and also on the second group ("MUSIC SAMPLES PART 2") which feature more conventional bands and acoustic sounds, I'd say the H6 bridges these different genres very well. There are very few headphones that have a decent deep bass response and reasonable impact but don't have any upper bass emphasis or bloat, and the B&O H6 is one of those few.
Isolation with the H6 is average or better for a good closed-back headphone, and although leakage is fairly low, it's not low enough to play music loudly in a quiet office in a cubicle next to other cubicles. If the office is very quiet, I think you'd have to keep the volume to a moderate level. The H6's physical design is one of the most perfect, if not the most perfect, that I've ever encountered. The black or brown trim colors over brushed aluminum are elegant, no part of the headphone bulges away from the head when wearing it, the earcups fold flat and pull down far enough to wear comfortably around the neck all day long when not in use, and the earcups are large enough to completely surround my medium-to-large ears in perfect comfort. The H6 is an unusually comfortable headphone, and the relatively light weight and light headband clamp will keep it that way.
The H6 single-sided cable is detachable with standard 3.5 mm straight miniplugs on either end, however those miniplugs are the extra-connector Apple type, and when I tried substituting a non-Apple generic cable, the plug going into the earcup would not make a proper connection. If Radio Shack or other electronics dealers have any cables with the extra-connector Apple-style miniplugs, those cables might work, but I can't be sure. The cable is ~1.5 m long, which is nearly perfect for portable use. Much of the H6's design seems to target it for portable and outdoor use, but the odd thing there is, outdoors is where most users appreciate the extra bass of most modern headphones, and the H6 is purely neutral in the bass. Some portable headphones come with stiff carrycases that offer good impact protection, but the H6 is supplied with only a cloth bag, which I don't find useful. The H6 fits into my Grado** carrycase perfectly, given a slight squeeze to the earpads to tuck them in.
**The Grado carrycase is sold only in Britain to my knowledge, but it's orderable for a modest shipping fee.
The music tracks listed in my older reviews were carried over from what I mostly listened to 5-10 years ago. As I added more headphone reviews, I've gravitated more toward "techno" music, from 1980's New Wave to current house music, and even some hip-hop tracks. This new list began at the 2013 New Year and continues here. The older list follows this newer list (see "MUSIC SAMPLES PART 2"). My suggestion is instead of reading each comment below as an absolute unto itself, you could compare these notes to other reviews as they get posted, and see how the H6 compares with each individual track.
Animotion - Obsession (1980's New Wave/Techno): The upper bass synth has excellent detail and tone, and both male and female vocals sound natural, without favoring either. The H6 plays this perfectly.
Ben Heit Quartet - Suite-Magnet and Iron (Jazz with a Bebop flavor): The piano that leads off sounds realistic and the saxophone sounds appropriately soft. Overall, the H6 plays this music extremely well.
Cath Carroll - Moves Like You (1980's New Wave/Techno): This track's percussion and voice are crisp and well-balanced, and there's a good sense of space or soundstage around the voices and instruments. The H6 reproduces the space and detail convincingly.
Chromatics - I'm On Fire (Synth-Pop, female lead): This track has a good amount of space around the voice and instruments, making for a very pleasant stereo image. The voice is excellent, and the tambourine sounds just right.
Crystal Castles - Wrath of God (Electro-Pop): The bass in this track has a strong impact but little detail, while the ambient electronic effects are clear and distinct. The H6 plays this track beautifully given the limited quality of the recording.
DJ Shadow - Building Steam With a Grain of Salt (Electronic/DJ): This track opens with what sounds like very high and very low piano notes, and the H6 renders those notes well. The ambient voices are slightly indistinct though.
Franz Ferdinand - Ulysses (Pop-Rock): The moderate level of bass in this track is played with good detail by the H6, and the percussion and voice are crisp and well-balanced. This track has a huge amount of high-frequency energy, but it plays smoothly with the H6.
Halie Loren - Sway (Jazz vocal): Bass instrument(s) here may sound boomy with some headphones, but the H6 handles this pretty well. The trumpet sounds natural but soft, and the voice is done just right.
Hans Zimmer - Dark Knight-Aggressive Expansion (Soundtrack): The percussion in this track hits really hard, and the bass tones beginning around 0:45 have the ultra-deep "shuddery" kind of sound and feel that indicates a good deep-bass response. Overall, the H6 plays this music extremely well.
Kaskade - 4am (Electro-House): The bass that kicks in around 1:01 into the track is subtle, but the H6 plays it well. The percussion and female voice balance well with neither overwriting the other - the H6 gets this right.
Katy B - Perfect Stranger (R&B-House-Garage): The heavy bass that begins at 0:27 into this track is played very well by the H6. The voice is slightly forward, but it doesn't overpower the instruments or get lost in the mix. The H6 balances the different elements in this music very well.
Machine Gun Kelly - All We Have (Rap/Hip-Hop): The heavy bass beats that begin at 0:23 into the track do sound like drum impacts, although they're not sharp impacts. The male and female voices have a good balance, and the H6 plays this about as good as can be expected given the limited quality of the recording.
Massive Attack - Angel (Trip-Hop): This track begins with a steady low-frequency sound and some strong deep-bass impacts. The voices blend well with the music and have just the right presence, although the recorded quality of the instruments isn't great. The H6 plays this about as good as can be expected given the limited quality of the recording.
Morcheeba - Bullet Proof (Trip-Hop): Bright percussion and medium-strength bass impacts make up most of this, with some dance-club spoken intonations thrown in. The H6 plays the percussion pretty well, and the voices sound good too.
Peter Tosh - Get Up Stand Up (Reggae): The bass here has a decent but moderate impact, and the lead and backup voices have good separation that's not too narrow or wide. The H6 renders the bass with great detail and the voices sound very natural.
Porcupine Tree - Trains (Pop-Rock): This track opens with some nicely-detailed string sounds and a forward-sounding male voice with a higher-than-average register. There are a series of "clip-clop" effects starting at 3:19 that may lack clarity and proper harmonic detail on some headphones, but the H6 reproduces those effects perfectly.
Rachmaninoff - Prelude in C-Sharp Minor Op3 No2 (Classical, Piano): Grand piano played mechanically from an original recording by the master himself. The bass is unusually light here, but the H6 renders the notes very well given the limited quality of the recording.
Scarlatti-Kipnis - Sonata in E Major K381 (Classical, Harpsichord): The harpsichord here is fairly bright and highly detailed, and the H6 renders the tones and transients superbly.
Trombone Shorty - Backatown (Jazz-Funk): The deep bass impacts here are unusually strong, and work very well with the horns and other instruments. The H6 delivers the impacts with proper weight and great detail, and the horns have the kind of bite that gives them a wonderfully realistic sound.
William Orbit - Optical Illusion (Billy Buttons Mix) (Electronic): This is about as close as I want to get to easy-listening music. The string tones beginning at 0:18 have appreciable detail, and while the bass isn't very strong, it still adds a good underpinning to the music. The short poetic rap at 4:14, preceded by an etherial female voice, works very well with this track.
---------- B&O H6 REVIEW - MUSIC SAMPLES PART 2 ----------
Bauhaus - Bela Lugosi's Dead (~1980): Strong midrange sound effects - this is a good worst-case test for resonant-type sounds in the most sensitive midrange area. Handled extremely well by the H6.
Beethoven Symphony 9, Solti/CSO (1972): Excellent overall sound. Of special note for this headphone are the bass impacts beginning around 10:30 of the fourth movement. Those impacts won't overwhelm you since they're soft and well in the background, but you can really feel the weight they carry.
Blues Project - Caress Me Baby (1966): Rarely mentioned, but one of the greatest white blues recordings ever. The loud piercing guitar sound at 0:41 into the track is a good test for distortion or other problems. Handled very well here.
Boz Scaggs - Lowdown (1976): Good sound quality - this is a great test for any nasality in the midrange. Handled fairly well by the H6.
Buffalo Springfield - Kind Woman (~1968): A Richie Furay song entirely, rarely mentioned, but one of the best sounding rock ballads ever. This will sound good on most headphones, but it's a special treat with the H6.
Cat Stevens - Morning Has Broken (early 70's): A near-perfect test for overall sound - this track will separate the best sounding headphones from the lesser quality types. Nothing specific, except that almost any deviation from perfect reproduction will stand out with this track. Sounds very good on the H6.
Catherine Wheel - Black Metallic (~1991): Goth with industrial overtones - I like this since it's a great music composition and the sound effects are smoothly integrated into the mix. This may sound distorted or mushy with some headphones, but the H6 renders the deliberate instrumental distortions clearly.
Def Leppard - Bringin' On The Heartbreak (1981): MTV goth/pop/metal at its best - good ambience and high energy - the better headphones will separate the details and make for a good experience. Lesser quality and the details tend to mush together. The H6 plays this very well.
J.S. Bach - E. Power Biggs Plays Bach in the Thomaskirche (~1970): Recorded on a tracker organ in East Germany, the tracks on this recording have the authentic baroque sound that Bach composed for, albeit the bellows are operated by motor today. The H6 plays the tones seamlessly through the upper limits of the organ, which cover nearly the full range of human hearing. Of special note are the pedal notes - tracker organs have low-pressure pipes and don't typically produce the kind of impact around 30-35 hz that modern organs do. A headphone that's lacking even a little in the low bass will sound especially bass-shy with this type of organ, but the H6 delivers the full experience of this music.
Jamming With Edward - It Hurts Me Too (1969): Intended originally as a test to fill studio down time and set recording levels etc., this was released a few years later for hardcore Rolling Stones fans. Although not as good technically in every aspect as the Chess studio recordings of 1964, and in spite of the non-serious vocals by Mick Jagger, this rates very high on my list of white blues recordings, and sounds absolutely delicious with the H6.
Jennifer Warnes - Rock You Gently (1992?): The strong deep bass percussion at the beginning of this track has been cited as a test for weakness or distortion in certain headphones. The H6 plays those notes with good impact and control. Having played this track a number of times now, I'm highly impressed with the H6's bass reproduction and detail throughout the track.
Jimmy Smith - Basin Street Blues (early 60's): This track has some loud crescendos of brass and other instruments that don't sound clean and musical on some headphones. The H6 provides excellent reproduction. Listen particularly to the second crescendo at 15 seconds in, for maximum detail effect. I'd like to emphasize that these crescendos are probably the worst-case test I have for instrumental separation and detail, and the H6 plays them very well.
Ladytron - Destroy Everything You Touch (~2009): Featured in The September Issue, this song has heavy overdub and will sound a bit muddy on some headphones. Sounds great with the H6.
Milt Jackson/Wes Montgomery - Delilah (Take 3) (1962): The vibraphone is heavily dependent on harmonics to sound right, and the H6 plays it perfectly.
Pink Floyd/Dark Side of the Moon - Speak To Me (1973): Strong deep bass impacts will be heard and felt here.
Rolling Stones - Stray Cat Blues (1968): Dirty, gritty blues that very few white artists could match. On some headphones the vocals and guitar lack the edge and fall more-or-less flat. If you're a really good person, playing this song will probably make you feel nervous and uneasy.
Tony Bennett - I Left My Heart In San Francisco (1962): Frank Sinatra's favorite singer. Highest recommendation. With some of the best headphones, the sibilants on this recording are very strong, but they're not bad with the H6.