Youtube review: http://youtu.be/S0VyUAmBrMs
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 Form2: A definite hi-fi signature due to a full treble response, with a moderate emphasis around 3 khz, and a rather light bass. The light bass isn't surprising given that the Form2 is a 25-year old model still in production (although the materials and QC have probably been improved over the years), and that it was B&O's version of the lightweight plastic headphones made for Sony Walkman cassette players of that day. The good (and unusual) news is that the Form2 sound improves greatly with the iPod "Bass Booster" EQ setting, or the equivalent setting on computer music players. This is the first headphone I've had that takes a simple iPod bass boost without becoming muddy or otherwise unclear. Note that all comments from here on refer to the sound of the Form2 with the Bass Booster EQ applied, because (in my opinion) it wouldn't be a hi-fi headphone otherwise, and I don't review non-hi-fi headphones. Bass Boost is on from here to the end of the review.
After a short burn-in period and listening to 100 or so familiar music tracks, I ran several tone sweeps and tests with discrete tones. The bass (noting the above comments about EQ) is down slightly at 40 hz, down significantly at 30 hz (perhaps 6 db), and there's little or no useful response below 30 hz. However, the 30 hz response is solid fundamental, judging by the sound and the weight. In spite of what I consider a satisfactory bass response, it's still not going to please anyone who requires an audiophile "flat" bass, although it gets close to that. The sound progresses smoothly through the midrange and treble, including the upper treble, with only the moderate (perhaps 4 to 5 db) emphasis around 3 khz to spoil a near perfect signature. The end effect of that 3 khz emphasis is to give some instruments and voices a harder edge than normal, necessitating a lower listening volume. Offsetting that edge somewhat is the slightly distant overall perspective, most noticeable on voices.
The less-than-ideal news is the quality, clarity, tonality - whatever describes the difference between headphones that have the same signature, or balance of bass, mids, and treble. The Form2 does have a significant midrange coloration, congestion, or other negative attributes that would disqualify it for audio perfectionists or persons who demand accurate musical tone from top to bottom. In my view, this is relevant for those persons, and for anyone else who is inclined to compare the Form2 directly to other headphones that have a higher fidelity, where the differences would be obvious. However, listened to on its own with a wide variety of music genres, I find the sound to be very enjoyable, very detailed, and quite satisfactory for all practical purposes. I would recommend against "amping" this headphone, in spite of the fact that the efficiency is low to begin with, and with the necessary bass boost, is even less efficient.
I'm running at 90-95 percent volume on the iPhone/iPod Touch, and I have some tracks that have adequate volume only when played indoors at night when it's very quiet. If I recommended a headphone amp for the Form2, something like the PA2V2 would be a good bet since it wouldn't tighten up the bass significantly, making it sound too thin. The soundstage of the Form2 is quite good, being an open-back headphone and also having a full treble. Sibilants and other treble irritations won't be a problem with the Form2, unless a user plays it without Bass Booster EQ. I don't have the Sennheiser PX100ii or PX200ii headphones around now, but mentally comparing to those equally small plastic headphones (and after reviewing my testing notes), the Form2 does not have the strong bass of the PX100ii, but does have a much better treble. Compared to the PX200ii, the Form2 is better on both ends, and even when the PX200ii is EQ'd as I described in a previous review, its overall sound quality is well below that of the Form2.
There is no real isolation with the Form2 since it's an open-back headphone, but the leakage is actually pretty low - low enough that the Form2 can play music at a moderate listening volume in a typical office with no problem, unless the office were dead quiet and a person with very sharp hearing sitting close by happened to hear the very faint sound and objected. The Form2's physical design is very minimal - a simple plastic headband, tiny earpieces that adjust up and down a good amount for heads larger and smaller than mine, and a thin dual-entry non-detachable 4 ft. cord that's terminated with a standard 3.5 mm stereo miniplug. The earpieces swivel about 5 degrees each direction, to fit different head shapes. The drivers, which appear to be about 25 mm in diameter, could be slightly larger (such as 30 mm), but I can't confirm that. The earpads are a thin foam that may last a year with very careful use, but will deteriorate more quickly if exposed to much perspiration, or extremes in temperature.
The Form2 earpieces will pull down far enough that the headphone can be worn comfortably around the neck all day long when not in use, making the Form2 an ideal portable headphone from that perspective. Unfortunately, there is no carry case supplied that can protect the very fragile Form2 headphone should the user want to stash it in a backpack or airline luggage, etc. The Form2 arrived in a simple B&O Box - same as the H6 headphone except smaller - but unlike the H6 headphone, the Form2 didn't include any accessories - just the headphone.
Summarizing, while the Form2 falls short of being a full-fledged high fidelity headphone in certain ways, it still provides an enjoyable experience for my listening. There's a term that some reviewers use to describe a headphone that they enjoy listening to, which nonetheless has sonic flaws that by all rights should disqualify it as a High Fidelity item: "Fun". I know this from reading the reviews, not because I know what "fun" means. And though I don't know what "fun" really means to any particular reviewer, the Form2 might quality for that if a strong bass isn't required. Specifically, my minimum requirements for hi-fi listening are an even balance of bass, mids, and treble, with no irritating peaks or emphases, and no major suckouts that have me straining to hear the missing information. I have a pretty good tolerance for many colorations, as long as the sound of voices and instruments is musically realistic, and those sounds are realistic and very musical with the Form2.
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 Form2 plays the different types of music listed here compared to other headphones. 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 Form2 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 Form2 plays this very well, but the percussion is rather bright, which may limit the playback volume for some users.
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 Form2 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 Form2 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 oddly enough, the tambourine sounds more like a tambourine than with any other headphone I've played this track with.
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 Form2 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 Form2 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 Form2, and the percussion and voice are crisp and well-balanced. This track has a huge amount of high-frequency energy, which may limit the playback volume for some users.
Halie Loren - Sway (Jazz vocal): Bass instrument(s) here may sound boomy with some headphones, but the Form2 handles this very well. The trumpet is soft but has a recognizable trumpet bite, and the voice is done just right.
Hans Zimmer - Dark Knight-Aggressive Expansion (Soundtrack): The percussion in this track hits really hard. The bass tones beginning about 0:45 have an ultra-deep "shuddery" kind of sound which the best headphones play with proper weight, but most of that weight is missing with the Form2. The fact that you can hear and feel some of it is excellent performance for this type of headphone, judging by design rather than cost.
Kaskade - 4am (Electro-House): The deep bass that kicks in around 1:01 into the track is subtle, and mostly missing with the Form2. The percussion and female voice balance well with neither overwriting the other - the Form2 plays this well.
Katy B - Perfect Stranger (R&B-House-Garage): The heavy bass that begins at 0:27 into this track is played lightly by the Form2. The voice is slightly glassy, but it doesn't overpower the instruments or get lost in the mix. The lightness of the deep bass and the bright vocals may serve to limit the playback volume for some users.
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 Form2 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 Form2 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 Form2 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 Form2 plays the bass lightly but with with good 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 lack clarity and proper harmonic detail on some headphones, and the Form2's reproduction is off here as well.
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 Form2 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 Form2 renders the tones and transients superbly.
Trombone Shorty - Backatown (Jazz-Funk): The deep bass impacts here are unusually strong with most headphones, and although the Form2 delivers those impacts satisfactorily, they're significantly lighter than with other larger headphones. The horns as played by the Form2 have enough bite to give 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 little detail, and while the bass isn't 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 Form2 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 well by the Form2.
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 with any headphone since they're soft and well in the background, but the Form2 impacts are significantly lighter than with most full-size headphones.
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, and the piercing aspect of that sound is more prominent with the Form2 than with my other headphones.
Boz Scaggs - Lowdown (1976): Good sound quality - this is a great test for any nasality in the midrange. Handled fairly well by the Form2.
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 Form2.
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 Form2.
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 Form2 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 Form2 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 Form2 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 seriously lacking in the low bass will sound especially bass-shy with this type of organ, but the Form2 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 pretty good with the Form2.
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 Form2 plays those notes with light impact but good control. Having played this track a number of times now, I'm highly impressed with the Form2's overall 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 Form2 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 Form2 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 Form2.
Milt Jackson/Wes Montgomery - Delilah (Take 3) (1962): The vibraphone is heavily dependent on harmonics to sound right, and the Form2 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. The Form2 plays this well.
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 an issue with the Form2.