Soundmagic P21 Portable On-Ear Stereo Headphone review

Discussion in 'Headphone Reviews' started by dalethorn, Jul 25, 2014.

  1. dalethorn

    dalethorn Obsessive Auditor

    Jul 3, 2011
    Charleston South Carolina
    Youtube review:


    Sources: iPhone5 with Portaphile Micro/PA2V2/Decware Zen Head amps using the LOD, various computers using Microstreamer/Beyer A200p/v-moda Verza DAC/amps.

    Review note: My first impressions of the sound of the P21 are based on direct comparisons to other headphones - the v-moda M80 and M100, the Beyerdynamic DT1350, T1, and T90, the FAD Pandora IV and VI, and notes I've accumulated from many prior reviews. I describe how I relate to the P21 (i.e. my personal tastes and how I use the headphone) only after covering all of the objective issues.

    My first impression of the P21 was a very nearly full-fidelity sound, with just a slight recess in the mid-treble. This would be good for a $125 USD headphone, and really great for an $80 headphone. But given the actual P21 price, it's no less than spectacular. I've had the full-size Soundmagic HP100 and HP200, and I've had two of the Beyerdynamic DTX501p, which I believe is an OEM version of the Soundmagic P30. All of these, from the HP200 down to the P21 are excellent, and not just good for the price. As small and light as the P21 is, and noting the all-plastic (except for metal in the headband) construction, I've come to realize just how much quality Soundmagic has built into this headphone.

    To see more graphically how I hear the P21 sound, refer to the chart linked above, or on my dalethorn site under Photos and Audioforge. Specifically, I hear a small emphasis around 85 hz which can slightly emphasize boomy effects in tracks that have quality problems in that area. There's a moderate emphasis around 900 hz, which can make voices a bit more forward than "flat"-response headphones. There's a small recess around 2.5 khz and a small emphasis around 5 khz, followed by a rolloff above 9 khz. All in all, this is the smoothest and best-balanced sound I've heard from this type of headphone until I hit the $100 USD level with the Beyerdynamic DTX501p.

    Summing up, the P21's sound qualities:

    The soundstage is good, and the musicality is very good.

    The comfort is excellent with the very soft earpads that don't pinch my ears, and the headband clamp is very light.

    The flat rubber cable (which looks strong) is as ideal as I've seen in a small portable headphone.

    The portability is perfect insofar as having the ability to wear around my neck comfortably when not listening, plus the inclusion of a decent form-fitted and zippered carry bag for stowing in luggage or backpacks. Isolation is good - enough to be able to enjoy music in places that aren't extremely noisy, but not enough to get a sense of significant isolation. The moderate amount of leakage could be a problem in quiet offices or public libraries, unless the volume is kept to a modest level. The earpads are a special type of leather, and they form a good seal to the head which insures a full bass response. The 4.5 foot long dual-entry and non-detachable cable is the 'flat' type - an ideal design I think - and should hold up very well in daily use.

    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 P21 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 P21 compares with each individual track.
    Last edited: Jul 25, 2014
  2. dalethorn

    dalethorn Obsessive Auditor

    Jul 3, 2011
    Charleston South Carolina
    Soundmagic P21 review part 2 - music tracks

    Animotion - Obsession (1980's New Wave/Techno): The upper bass synth has good detail and tone with a modest weight, and both male and female vocals sound natural without favoring either. The P21 plays this perfectly.

    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 P21.

    Beethoven Symphony 9, Solti/CSO (1972): Excellent overall sound. Of special note here are the bass impacts beginning around 10:30 of the fourth movement. Those impacts are soft and well in the background, but you can really feel the weight they carry with the P21.

    Black Sabbath - Iron Man (Classic Rock): Very good instrumental detail and the vocal sounds very natural. As with most classic rock tracks, there is very little or no deep bass. The P21 plays this music perfectly, and the lack of deep bass doesn't unbalance the treble.

    Boz Scaggs - Lowdown (1976): Good sound quality - this is a great test for any nasality in the midrange. Handled extremely well by the P21.

    Cantus - Danny Boy (Traditional/Male Choral/Acapella): The P21 plays these voices with enough low end warmth and weight to sound very natural, yet there is no added emphasis of the lower register of the male voices on this track.

    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 P21 reproduces the space and detail convincingly.

    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 P21 renders the deliberate instrumental distortions clearly.

    Chris Isaak - Wicked Game (Pop/Rock): The P21 plays this high treble energy recording very smoothly - the voice and instruments are detailed but not sharp or edgy.

    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 sound is very realistic.

    David Hazeltine - Fur Elise (Jazz): A very high-quality recording from HDTracks. The P21 reproduces the instruments smoothly with a spacious ambiance. The wire-brush-on-cymbal harmonics are very extended and detailed, albeit the highest harmonics are a little weak.

    Grieg (Beecham-Royal Philharmonic) - Peer Gynt-Solveig's Lullaby (Classical): This very old (late 1950's) stereo recording must have been made on the most expensive gear in the world, since the overall sound quality and especially Ilse Hollweg's amazing voice are as close to "being there" as I've heard with some of the better classical recordings made since the year 2000. The P21 plays this music perfectly.

    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 P21 plays this music very well.

    Heaven 17 - Let Me Go (1980's New Wave/Techno): The bass instrument (guitar?) has very good detail, and the voices and ambiance have a "you are there" quality that's uncommon in early 1980's pop music. The P21 plays this track perfectly.

    Hugo Audiophile - 15-16 (Electronic): I'm not sure what the 15-16 stands for - perhaps track numbers from a CD album. The deep-bass tones that start around 33-34 seconds into the track reproduce very well with the P21. This is a great recording for evaluating whether a headphone's bass will be sufficient for most environments, since for many headphones that have a weaker bass, the deep bass gets absorbed and mostly lost when the environment contains a lot of low-frequency energy.

    Human League - Keep Feeling Fascination (1980's New Wave/Techno): This track's bass line is very detailed, but the somewhat forward voices don't have quite the "you are there" quality of the Heaven 17 track noted above.

    Jimmy Smith - Basin Street Blues (early 60's): This track has several loud crescendos of brass and other instruments that don't sound clean and musical with some headphones. The P21 provides excellent detail. 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 instrument separation and detail, and the P21 does those extremely well.

    Kellogg Auditorium, Battle Creek Michigan, Aeolian-Skinner Organ (1933) - Pedal, 32', Resultant, Arpeggio: This 16 hz organ pedal tone differs from other music tones in that you won't "hear" the tone - you'll only feel it. Although most music tones have harmonics (including this one), the harmonics from this tone will be too weak to provide any "feel", so whatever you actually hear would not be part of the fundamental 16 hz tone. There are ~30 hz sounds in the outdoor environment in big cities, generated by large trucks, buses, and subway trains, and they have a quality of "rumble" that's similar to some deep-bass tones found in music. This 16 hz organ tone is easily distinguished from those sounds when compared on a headphone that has good undistorted response at 16 hz. The P21 sound is good with plenty of the 16 hz fundamental, but that fundamental isn't as detailed and clear as some of the larger more expensive headphones.

    Mantovani - Sunrise Sunset (Easy Listening, ca. 1972): A master musician and conductor who specialized in light classics and orchestral pop music, Mantovani's accomplishments were overshadowed by music critics who couldn't tolerate the notion of "light classics" or "semi-classical" music, even when those recordings were no threat to the classical music genres. In any case the later Mantovani recordings from the mid-1960's through mid-1970's had the advantage of being mixed for much better hi-fi systems than those which the music critics possessed at the start of the Long Playing (LP) record cycle. Here in 2014, at least some of those digital remasters have improved the sound further, although it's not always the case. This track as played on the P21 is an excellent example of the sheer musicality lurking in those later recordings, and is highly recommended for soundstage, instrumental tone, and musical balance.

    Michael Tilson Thomas - Rhapsody In Blue (20th Century Classic): Great sound and soundstage, and terrific piano playing and tone. There are some very deep bass impacts starting around 38 seconds into the 17:24 length track, and the weight of those impacts is very impressive with the P21.

    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 should sound like they were made with wooden blocks of some kind. The P21 reproduction isn't completely accurate insofar as the 'clop' part of the sound effect has a lighter tone than it should.

    Richard Strauss (Mester-Pasadena) - Also Sprach Zarathustra (opening) (Classical): The granddaddy of bass is in the opening 1:50 of this recording, and I've heard it only once on a large and expensive loudspeaker system in Cleveland. For most people, that experience would be indistinguishable from being in a fairly strong earthquake. The P21 conveys as much of that experience as is possible given its small size and light weight, but the deep (33 hz) bass has less detail than some of the larger more expensive headphones.

    Scarlatti-Kipnis - Sonata in E Major K381 (Classical, Harpsichord): The harpsichord here is fairly bright and highly detailed, and the P21 renders the tones and transients very well.

    Trombone Shorty - Backatown (Jazz-Funk): The deep bass impacts here are very strong, and work very well with the horns and other instruments. The P21 delivers the impacts with great weight and 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 are fairly soft, and while the bass isn't very deep, 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.
  3. dalethorn

    dalethorn Obsessive Auditor

    Jul 3, 2011
    Charleston South Carolina
    P21 rating?

    I don't do ratings of headphones because it distracts from the message - i.e. the specific details of the sound and utilization that customers need to know before purchase. But the P21 represents (in my experience) a breakthrough in quality anywhere near its price tier. So here's a stab at a rating for the P21 - 10=best, 1=worst. These ratings would be based on my experience with portable on-ear headphones under £150 or so.

    Bass impact: 9
    Bass detail: 8
    Mids clarity: 8
    Mids coloration: 7
    Treble balance: 9
    Treble coloration: 8

    Appearance/aesthetics: 9
    Comfort: 8
    Range of head sizes: 8
    Cable: 7 (non-detachable
    Earpad and headband pad quality: 9
    Est. durability: 8

    Size and weight: 9
    Wear around neck: 9
    Earcups fold flat: 9
    Carry case: 7 (form-fit and zippered, but soft)

    Total: 132/16 = 8.25 average out of 10.

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