Earbud buyer's guide, feat. TM5, OK1, PK1, ATH-CM700, OK2, K319, OK3, PK3, PK2
Oct 11, 2008 at 2:49 PM Thread Starter Post #1 of 226


Headphoneus Supremus
Dec 23, 2006
*** This guide was significantly revised and updated (OK3 and PK3 added) on May 1, 2010. If you read it before, I recommend to re-read it.

[size=medium]Top earbuds buyers guide[/size]

This is a buyers guide showing general directions rather than extensive review or comparison. There are a lot of comprehensive reviews and comparisons at Head-Fi, including my owns, and I list some of them in the guide.

[size=x-small]What are the earbuds?[/size]

There is some confusion on this term, some people refer earbuds to IEMs (like Etymotic ER-6i), canal phones (like Sennheiser CX300) and hybrids (like Sony EX-90). True earbuds are shown on the pics below:


Update May 11, 2009 - AKG K319 added:


Update Apr 10, 2010 - BLOX TM5 added:


Update May 1, 2010 - Yuin PK3 and OK3 added:

I would not post PK3 and OK3 pics, since they are built similar to PK1/PK2 and OK1/OK2 correspondingly, which are already shown above.

[size=x-small]Why earbuds?[/size]

They are good at walks when isolation is not recommended. They are very portable, it is easy to carry them around. Unlike to any other headphone, they are comfortable enough to "disappear" in your ears. You may lie with or on them. They are quick to put them in and pull them out.

[size=x-small]Why did I listed too few earbuds and why they are expensive?[/size]

This guide is result of my own quest for the earbud which may sound as good as full size can. I tried a lot, but just few sound good. So I mention only the best and some of them are quite expensive.


Buying any of the expensive earbud you'd better listen to it before. Earbuds sound perception varies extremely from person to person. Look, I'm fond of PK1 and my GF likes CM700. The same time, she hates PK1 ("too boomy!"), while I can not stand stock CM700 ("too ringing!"). There are no such big differences in personal perception with IEMs or big size cans, so take this into consideration.

[size=medium]How good is the earbuds sound quality (SQ)?[/size]

Some may consider earbuds to be inferior to full-size cans and they are wrong. Modern top earbuds are on par with Mid-fi and Hi-Fi full-size headphones in terms of overall SQ. They also stand well against most IEMs, while beat them easily in terms of soundstage and comfort.

My sound quality ranking chart for May 1, 2010

I tried more than 90 headphones, but I list only those I may rate with confidence. I divide them into the 5 classes by sound quality alone - Hi-End, Hi-Fi, Mid-Fi, Low-Fi and Consumer Grade. Then I divide some classes with 3 subclasses - like H1, H2, H3 for Hi-Fi. Inside the rows headphones are listed in the order of my personal preference with no regards to the pricing - I asked myself: "Which do I like more to receive as a gift?". I also discovered an interesting phenomena - I prefer some headphones (say DT770) to those higher rated (say DT880). Unfortunately, I found no way to represent this in a simple way.

I made the headphones I reviewed clickable or bold, most links lead to their reviews or descriptions. This chart may differ from its previous versions shown in my former reviews. Most of the cans from L category are rated un-amped, some of them (say Koss) may move up when amped.

HE Tesla T1

H1 HD650; RE262; W5000; ER-4S (custom tips, OFC cable); AD2000
H2 RE252km; RE0 (custom tips, no filter); CK10; ER-4S (custom tips); D2000; E500 (same to SE530); K701; W1000; HD600; AD1000PRM
H3 TM5; RE0; RE-Zero; ER-4P (custom tips); DT880/250; AD1000

M1 K501; G1A; ER-4P; DT990/250; OK1; AD900; SA6; UM2; Ergo 2
M2 KSC-35km; PK1; MDR-F1; AD700; DT770/80; SR225; HD595; E4c
M3 G2A; SR80; EW9; ER-6i; CM700; HD555; DT660; HD280

L1 OK2; iGrado; HD485; PX100; PMX100; UE 5 EB; A900
L2 MDR-Q68LW (EQ-ed); UR40; OK3; PortaPro; K319; SportaPro; Grado clip-ons; D-Jays; DT231
L3 PK3; KSC-75; PXC250 (leather pads); PK2; UE 3; E2c; CX300

CG v-Moda Vibe; HA-FX33 (kramer mod); SHE2550; SHP2700; iPod earbuds; K27i ; SHL9500; MX75
[size=medium]Personal preferences and genres based recommendations[/size]

I did my best to be as objective as possible ranking SQ alone in the chart mentioned above. But there are also some of my personal preferences and recommendations:
  1. My personal favorites and best all-rounders are TM5, PK1, PK3. I like involving headphones with deep weighty bass, warm mids and excellent PRaT. The same three earbuds are the best for rock, blues and blues-rock.
  2. Jazz and vocal listeners should carefully choose between TM5, OK1 and PK1.
  3. If you tend to analytical sound with perfect soundstaging, precise timbres and details then I recommend you OK1 and CM700. Classical, acoustic and sometimes vocal music do benefit with these cans.
  4. Those who like electronic music with a lot of spatial cues (say trance, ambient) would be pleased by CM700, K319 and OK2.
  5. Metal, hard-rock and house lovers can not miss with PK1 and OK2. These two are the best "energizers".
  6. Those who listen to congested, overloaded music would benefit from the terrific speed and instrument separation of CM700 and K319.
  7. If you are on budget and seeking for the best mids for your money, get PK2.
  8. If you are on budget and soundstage size, instrument location and positioning are crucial, get OK3 or K319.
  9. If you don't care, get PK3.

    Fit and comfort

    Unfortunately, all of these earbuds have basic round shape, which is comfortable but does not allow for stable fit. When you are walking, they tend to slip out of the ears. If stable fit on the move is important for you, check clip-ons headphones - see my Best clip-ons comparison. Those with bigger ears may try Yuin OK series - these are bigger itself and have removable rubber extenders inside the box. But be aware, that some people complain that OK series is less comfortable comparing to regular earbuds. You may also try some thicker foams and third-party silicon rings, like those I mentioned in MX75 foams thread.

    There are also earbuds which has more stable fit - either with hooks (clip-ons) or specifically shaped, like sport series from Sennheiser. I tried some and found them not good enough to review here.

    [size=medium]Brief descriptions[/size]

    [size=x-small]#1. BLOX TM5 - “Musicality” (added Apr 10, 2010)[/size]

    TM5 is the most efficient among the best earbuds and the best among the most efficient. It does not need amp, but faithfully reproduces the sound of the chain before it. The only perceptible things TM5 adds to the sound are the mellowness and touch of warmth, reminding me the blessed times of analogue tapes. Except the bass, TM5 has even frequency response and accurate tonality. TM5 has the most powerful bass I heard from the earbuds. This bass is of high quality and does not intrude into the rest of the spectrum. It is not so “exaggerated” but rather a “full-size” bass you may like with the big cans.

    More in my review: BLOX TM5 - top earbud, competing with PK1 and OK1

    Cons - I hardly know any. But there are some points requiring an attention:  
    1. Bass demands the respect; it may be too much in some ears with wrong foams or fit.
    2. TM5 does not exaggerate the details, so it would not help dull source to sound better.
    3. It does not make music more “fun” or “exciting” than it is. It is neither “rocking hard” or “analytical”, it is just “see-through”.
    4. Burn-in time is no less than 100 hrs; bass may hit too hard before this mark.
    You will probably like it if you like HD650, D2000.

    [size=x-small]#2. Yuin OK1 - “Accuracy”[/size]

    It provides analytical, extremely accurate sound in any terms – tonality, details, instrument separation and positioning, frequency response, etc. It beats most of mid-fi cans in terms of general SQ, so it may dethrone them easily due to the portability and comfort.

    More in my review: Yuin OK1 - review and comparisons

    1. Needs an amp. Tube, hybrid or warm SS are appreciated. Otherwise it sounds a bit lifeless.
    2. Sounds much better when loud, so it provokes to crank the volumes up.
    You will probably like it if you like DT880, K701.

    [size=x-small]#3. Yuin PK1 – “Pleasure”[/size]

    It sounds both smooth and detailed, with nice attack and rich decay. Lows are deep and very punchy, mids are warm and forward, upper mids and lower highs are emphasized. This gives it a euphonic sound even at low volumes. PK1 is very fun and energetic; it is probably the most involving headphone I listened, on par with the Grado. SQ competes easily with many of the mid-fi cans, while PK1 is more comfortable and less demanding to amplification.

    More in my reviews of TM5 and OK1 I mentioned above, both of them include extensive comparison to PK1.

    1. Distorts deepest lows, though it is unnoticeable unless you test with sine waves.
    2. Sometime may have a little sibilance.
    You will probably like it if you like: DT990, Grado.

    [size=x-small]#4. Audio-Technica ATH-CM700 – “Details”[/size]

    I love&hate this ugly duckling. “Ugly” is not about its look, which is excellent BTW. This is all about its sound. It always fools me with a feeling that it is capable to perform much better than it does. Trying to get the best from it, I changed the cushions, amps, EQs, added resistors… No luck! Sometime I will recable and reshell it (most likely in wood), I still hope this will help.

    It has excellent frequency extensions, going very deep and high. It has the best clarity and speed, it never sounds congested, separating as many instruments / voices as you throw in it. It has the widest soundstage, beating most of the full-size cans in this area! And it is extremely revealing, having terrific details, like those of Etymotic or electrostats.

    More in some old reviews (you may probably find newer):
    1. Nomad Audio Technica CM700: Qualias on earbud form factor (sadly without perfect fit)
    2. robbie CM700
    3. Elephas Audio-Technica ATH-CM700Ti
    1. At the same time it may sound flat, dry, thin, bright and sometime harsh. It happens with some songs, sources, with slight changes of in ear position. Or just happens.
    2. Unforgiving to bad records.
    3. Finicky to sources.
    4. Big caps and long sticks make them incomfortable and/or tricky to fit.
    You may like it (though I am very unsure) if you like: HD280, ATH-AD700, ER-6i. Some electrostats owners like it also. Again, I never heard any other headphone with so contradicting, love&hate character.

    [size=x-small]#5. Yuin OK2 – “Energy”[/size]

    It is opposite to CM700, it is not trying to bite off more than it can chew. It just does its job fairly. It does not have wide frequency extensions, but it has ruler flat frequency response. It is moderately detailed without harshness. Bass is very tight and detailed, mids are clear and “in-to-the-face” type, highs are just right. But it has its own character - overall sound is fast, punchy, clear, pleasantly aggressive… Are we talking about Grado? Almost, though OK2 mids yield to Grado magic vocals and guitars. But unlike the Grados I heard (from iGrado to SR225), OK2 imaging is terrific: instruments have bodies and positions, soundstage is 3D and deep.

    More in my review: Yuin OK2 review and comparisons to PK2, CM700, PK1 and OK1

    1. Lacks subtlest harmonics in comparison to upper earbuds, dropping the decay faster.
    You will probably like it if you like Grado.

    [size=x-small]#6. Yuin OK3 – “Diligence” (added May 1, 2010)[/size]

    It is easier to describe it like refined version of PK3. Bass is deeper, more even and accurate, while having tad lesser weight. Mids are more clear and detailed, while dryer. Highs are the same, soundstage and instruments separation are notably improved. At the same time, it is less emotional and involving. All these differences are not huge, so it is not easy to choose between OK3 and PK3. For outdoor listening I prefer PK3, while OK3 is better suited for quite places. Extra pricing ($59 vs $39) is well justified by the SQ improvements as well as a better package contents, like rubber covers of two kinds.

    Comparing to OK2, OK3 has deeper and bigger bass, while yields to OK2 in clarity, instrument separation, soundstage size and midrange details.

    Cons are the same to PK3, except the soundstage size, which is pretty satisfactory on OK3.

    You will probably like it if you like even-handed cans like HD600, HD555, AD900.

    [size=x-small]#7. AKG K319 – “Clarity” (added May 11, 2009) [/size]

    Speed and instruments separation are terrific, clarity is absolute. Soundstage is wide, though yields in depth to the TM5, OK1 and PK1. Tonality is slightly dry; frequency response is pretty even, with minor forgivable peak somewhere in lower highs. Bass extension is good, bass quality is excellent; mids lack warmth and harmonics; highs are not extended well but pronounced. Extreme legibility spans across the whole spectrum with no harshness or sibilance.

    All genres sound well with K319, those fast paced or imaging demanding benefit (say trance). In general, K319 is impartial, it is like a clean window to the music made of the somewhat cool-tinted glass.

    More in my AKG K319 beats PK2 review.

    1. Can not stand well to the mid-fi cans in terms of resolution and decay.
    2. Comfort is average, especially if you listen it under the hat.
    It sounds like lesser version of K701, keeping its tonality along with excellent speed, separation and clarity. Unfortunately, it lacks wonderful K701 mids, micro details and overtones.

    [size=x-small]#8. Yuin PK3 – “Best value” (added May 1, 2010) [/size]

    This is a "baby PK1". It resembles PK1 character and emotionality, while lacks its "mature" resolution - PK3 does not provide rich decay, subtle overtones or tiny details. But it does everything else with excellence. Bass is surprisingly deep, even and well controlled; its weight is same (or almost the same) to TM5. Mids are forward and very clear, with no hint of veil; midrange tonality is perfectly neutral and natural. This is probably why mids are pleasant and realistic, though they lack harmonics and details. Highs are emphasized a bit (after a good burn-in); they are rolled-off but sound quite gentle, balancing on the verge of sibilance. This results in pleasant and involving sound; PK3 gives me almost the same amount of goose bumps as PK1 does. Though soundstage is not as big as with OK series, it has fair depth with good instruments postioning. Clarity and instrument separation are beyond the expectations.

    It surprised me a lot. It is underrated at head-fi to no purpose but snobbism. Yes, it has no extra resolution or hyper speed, like higher cans. But it has coherent sound, plenty of fun and soul, similarly to PK1. For $39 it is a steal and I recommend it as first earbud to purchase; I believe many will be satisfied.

    PK3 performs any genre well. It is listenable on any volume down and is the best earbud for background listening. It is easy to drive though may benefit from amping and serial resistor, like P-to-S converter.

    1. It costs too cheap, so it is hard to believe how good it is.
    2. There is no high resolution (are you expecting it for $39?).
    3. Soundstage size is modest.
    4. Needs 100-150 hrs of burn-in to settle and shine.
    You will like it if you like music. Seriously, it is that good!

    [size=x-small]#9. Yuin PK2 – “Pathfinder” (updated May 1, 2010)[/size]

    Why did I rated both OK3 and PK3 above PK2, though its model number tells opposite? Well, PK2 does provide better resolution, more details and richer decay than both OK3/PK3 do. And PK2 mids are indeed livelier and better detailed than those of OK3/PK3. But this is where PK2 advantages end. Unfortunately, it looks like the step up in resolution caused some undesirable consequences in other sound qualities. There is a veil, which spans across the whole spectrum, compromising even those additional mids resolution.

    PK2 sounds very similar to stock (non-modded, unamped) KSC-75. Bass has mid-bass hump, lacks depth, speed and accuracy. Mids are warmer than neutral, slightly muddied, lacking clarity. Highs are tad emphasized and a sometimes edgy. Soundstage is somewhat collapsed, separation is so-so, overall sound is congested/veiled. I may recommend it over PK3 only if richer and more detailed mids (guitars, vocals) are you primary interests. Otherwise, PK3 is a safer bet.

    Same to the stock KSC-75, PK2 benefits from proper source matching and some tricks, like inline resistor. With regards to the numerous mods KSC-75 is known for, I recommend to avoid modding PK2. It is easier to buy OK2, which is "factory-modded PK2" most probably. And similarly to KSC-75, modded version is miles ahead of a stock.

    Despite all the critics, PK2 is definitely better than most of the customer-grade earbuds.

    You will probably like it if you like KSC-75, PortaPro, PX100.

    [size=x-small]The rest of the earbuds - pretenders and outsiders[/size]

    There are also some earbuds that worth to be bought, if you can not buy earbuds described above:
    1. ATH-CM7 and its derivations ATH-EC7, Bang & Oluffsen A8
    2. Sennheiser MX75, MX90
    3. Sony MDR-E888
    Some people may also mention ATH-CM3, Sony 828, MX500, some other buds. I heard many of them, and I’d better stay with iPod stock buds (which are quite good for background) or pay for some better earbuds to enjoy the music.

    [size=medium]Source and amplifications matching[/size]

    There are many who ask “Which is better unamped?”. This simple question does not have a sense, if you do not specify the exact source. Look, unamped Classic is miles ahead of unamped Shuffle 2ng gen. Moreover, Classic sounds very different from Cowon D2, while both are similarly powerful.

    Pay attention that the record itself also matters. Most of the modern records have boosted loudness (google for “Loudness war” to learn more). This may lead to clipping, when using EQ. When I normalized my records (with Foobar reply gain feature or MP3Gain) I was disappointed by the fact that Sansa Clip is not able to drive PK1 loud enough as it did before.

    So here I did my best to provide specific recommendations on sources/amps based on “normalized” records.

    TM5. Plays easy with anything, including weak sources. But being very transparent, it reveals the flaws of not so good source. Wearing MX75 foams, it has excellent synergy with iPod 5.5 gen headphone out. This combo sounds quite close to my WooAudio 3 > HD650 stationary rig, both in terms of SQ and sound signature. Of course, my stationary rig does sounds better, but large share of this improvement is provided by the source DAC superiority.

    OK1. It is the most hard to drive, even the most powerful DAPs (Classic, Cowon D2) are not enough to power it adequately. If you are not going to use an amp, you may find it a bit lifeless comparing to PK1. OK1 shines with tubes or hybrid, I bought TTVJ Millet Hybrid Portable to drive it and this was a match made on heaven.

    PK1. It is excellent with most of the amps, good with powerful DAP (Classic, Cowon D2) and acceptable with moderately powered one (Sansa Clip). It is not worthy to pay its price if you are going to drive it with the weak source (Shuffle 2nd gen), since it will sound muffled like PK2 while quieter. PK1 has nice synergy with Cowon D2, making a compact and great sounding combo.

    CM700. It is sensitive so it does not need an amp itself. It is extremely revealing so it is able to pull out good sound from weak, dark or non-detailed sources (Shuffle, mobiles, PC onboard sound cards). This is a double-edged feature and you are at risk with crappy records. Also avoid the sources, which are cold, bright, harsh or noisy. I do not even want to try it with Cowon D2, which is cold and dry. I may tolerate it straight out of smooth DAPs like iPod Mini 2G or FLAC updated Clip. Nevertheless, I recommend to use proper amp to further soften the source. The best portable combo I found for it is iPod Mini 2G -> XIN Supermicro IV with 4/11 mods. CM700 will take you to the heavens with the stationary rig like Lossless -> good DAC -> tube amp capable to drive low-impedance load.

    OK2, OK3, PK3. The most unpretentious, clear compatibility winners, they play well with anything (even Shuffle 2nd gen) and do not improve much with amplification. Detailed and fast amps with good frequency extensions and touch of warmth are recommended if you want to squeeze out the last tiny bit of SQ. What am I talking about? Meier Move / 2Move / 3Move, of course
    as well as original Pico. Based on the readings, I believe XXS (Headsix) and Predator are also good, though I never listened any.

    K319. Sensitivity is high; amplification is neither necessary nor improves the sound. Warm sources, like Sansas, are recommended to anybody; bass-boost option is must for bassheads.

    PK2. It is sensitive, so no amp is necessary. At the same time it is veiled, so need accurate matching. Avoid warm, dark or non-detailed sources. If you have Shuffle 2nd gen, choose OK2 or CM700. If you want go ultraportable with PK2, get Sansa Clip. For portable, choose Cowon D2 over iPod. You may benefit a bit from amp if you choose dry/cold/bass light amp instead of warm/bassy/smooth one.

    [size=medium]Background play[/size]

    This is very underrated and misunderstood category. Many pursue the best SQ while choosing an earbud primarily for background use indeed. Later they find themselves unsatisfied. What is the heck? Various types of background listening have their own specific requirements:
    1. Sometime you should listen quietly. For example, loud music will prevent you from monitoring the traffic around you at the streets. So headphone should play well at low volumes. Typically, it has to emphasize bass and treble.
    2. Sometime SQ should NOT be very good, neither in terms of accuracy nor in terms of fun. Otherwise the music will involve you, detracting your attention off your primary task (say reading or writing).
    3. SQ should not be bad at the same time. Crappy sound does also detract, especially if you are audiophile (are not you?). I prefer silence to any offensively sounding gear.
    4. Sometime sound should be comfortable and relaxed, say warm, without too many details, dynamics and so on.
    These requirements are not easy to meet simultaneously and I know few full-size cans which do that well - MDR-F1 and Koss UR-40 are those.

    My recommendations depending on the types of background listening

    PK3, PK1 and OK3 (though OK3 in lesser degree) are good for street walks due to the solid bass and accentuated highs. This lets you listen quietly and monitor the surroundings better for your safety. TM5 are also satisfactory for this purpose, though their cable become stiff when it is cold. Using TM5 for walks, I prefer the foams which open the highs, say donuts foams. All these earbuds may also serve well for office use, if you want to hear your colleagues.

    PK2 is the best for reading and writing, because its veiled sound does not distract the busy mind.

    PK1 and OK2 are excellent when you need energetic music support for some physical activities, like heavy metal or house for pumping iron or snowboarding.

    CM700, K319 and probably OK1 may help those, who altering their state of mind with some loud music to spur on creativity. I know some graphic designers, who listen to goa and psytrance when working; they believe this improves their productivity. I do not understand them, but I think these earbuds will suit them well

    TM5 and probably OK1 may support well reflections or meditations with the music like new age, ambient or chillout, due to their excellent spacial abilities, steady character and great frequency extensions.

    [size=medium]How to choose earbuds for your needs[/size]
    • First, estimate fairly your background and critical listening shares.
    • Then examine your music preferences.
    • Then decide which sources you will use.
    • With all this info use this guide to finalize your choice.

    1. I need an earbud for walks listening from the Clip. Answer: PK3.
    2. I need an earbud for gym listening metal from the Shuffle 2nd gen. Answer: OK2.
    3. I need an earbud for my bedside attentive listening of jazz from TTVJ Millet Portable. Answer: OK1.

Oct 11, 2008 at 4:00 PM Post #2 of 226
nice work..

i think its time i finally get PK1.
Oct 11, 2008 at 5:01 PM Post #4 of 226
i heard CX500 has a less bloatier and refined bass but still the CX series is all bassy
Oct 11, 2008 at 6:00 PM Post #5 of 226
Wonderful work. You'd deserve to try a Yuin G1 as I consider it a great choice for the price, and contender of the top with Pk1 and Ok1. The more I listen to the G1, the more I like its spectacularity.
Oct 11, 2008 at 6:42 PM Post #7 of 226
The only thing in which my opinion would differ, is that I don't fint the Ok2 gradoish, bur rather uncoloured, more neutral than Grados but less involving. I consider the Pk1 a lot more Gradoish with the boosted midbass and highs. But I admit I have only owned an SR-60, so I don't know how higher end grado's sound.
Anyway I consider the writeup to be terrific, and one of the most competent comparisons I have read about headphones on headfi.
Oct 12, 2008 at 4:29 AM Post #8 of 226
I added the comment on my Etymotic to justify its high ranking:

My ER-4P/S has soft silicone custom tips which sound MUCH better than any of the universal tips from Ety, Shure, Westone, Sleek-Audio (I tried all). I ordered my tips in local hearing protection clinic in Russia and they do not produce these tips anymore. So, I can not tell you where to order, sorry.
Oct 13, 2008 at 7:51 PM Post #13 of 226
Clarified some confusions regarding earbuds to IEM comparison. Right wording is:

They also stand well against most of the IEMs, while beat them easily in terms of soundstaging and comfort.

This corresponds better to ranking table H1 - L3.
Oct 13, 2008 at 11:45 PM Post #15 of 226
kostalex, Thanks for the great review on earbuds, I purchased the OK1 based on your first earbud review for my predator ipod classic combo, very happy with them. Also the sennheiser foamies top them off.I can wear them for 3 to 6 hrs. I forget I have them in my ears. Thanks again, Pete.

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