Harman Kardon CL Precision On-Ear Headphones with Extended Bass

  1. jazzfan
    Harman Kardon CL: An affordable on-ear alternative
    Written by jazzfan
    Published Nov 6, 2014
    Pros - Low street price; Good build quality; Efficient and easy to drive; Lightweight
    Cons - Colored sound signature (can be improved with mods); Comfort may be an issue for some
    The Harman Kardon CL (Classic) is a light weight closed back on-ear headphone that was introduced in 2012.  Since then, much has been written on this new headphone entry from Harman Kardon.  From most reviews I've read there seems to be general agreement on the overall tonal characteristic of the CL.  To summarize, the CL has an overall warm balance and a somewhat muted sound, due primarily to a mid-bass emphasis and rolled off top end - all of which, at least for the most part, mirrors my impressions of the CL.  I would add, what I also find missing is detail and air which results in a reduced sense of space.  With the CL you have a smaller, more intimate soundstage with less separation between instruments.

    Not wishing to repeat what seems to be general agreement on the tonality of the CL, I'll dispense with the typically treble, midrange, bass blow by blow headphone description of the CL.  Instead, in this review, I'll focus primarily on those aspects of the CL (both good and bad) that stand out for me which are bass, comfort, and placement. Then I conclude with a general recommendation for those considering the CL.


    The source used in this review was a Windows based PC running J.River Media Center v19 playing FLAC files with resolutions ranging from 16/44 to 24/192.  The primary DAC/Amp used to drive the headphones was a Light Harmonic GeekOut 450 that I purchased recently at the California Audio Show in August.  A Benchmark Media DAC1 PRE was also used briefly, but once the GeekOut proved up to the task I stayed with the Geekout.  The GeekOut 450 had more than enough power to drive the two headphones used in this review, and the dual headphone jacks on the GeekOut allowed two headphones to be simultaneously connected to the source for quick comparisons.


    A little background on my tastes.  I value good bass in a system. That is to say, I value bass that is solid, accurate, articulate, and that extends to 20 Hz, which is why I've augmented both my desktop and home theater systems with subwoofers.  Systems without a solid bass foundation to me are uninvolving and frankly, a bit boring.

    So by that measure does the CL satisfy this need?   No, unfortunately it doesn't.  What I found is the CL does have a healthy mid-bass bump in the 40-80 Hz region.  Some will find this to be too much of a good thing on some recordings.  But then again, on other recordings, this bass emphasis adds just the right amount of weight to make the CL fun to listen to.  When the music calls for it, the CL can also reach down and rumble in the 20-30 Hz sub-bass region which is quite impressive.  For an example, try the Heartbeat track on the Head-Fi and HDtracks presents Open Your Ears, or for some real fun listen to the drop (centered around 45Hz) at 1:08 seconds into the Datsik: Murder Style Original Mix track on the Speak No Evil EP and then again on the same track starting at 1:43.  It's sounds a bit woolly, but it still is impressive for this on-ear headphone.

    Comparing the bass to another on-ear I own, the V-Moda XS, the bass of the XS is more accurate from the standpoint of being flatter, and tighter than the CL.  But I like the fact that with the CL's enhanced bass, I'm able to listen at lower volume levels and can still enjoy the visceral impact of bass when it's present on a recording.


    Fit was an issue for me. Specifically, I found the standard headband clamping force to be heavy, too heavy to be comfortable for more than 1 or 2 hours. This is not a headphone I can wear all day without periodic recovery breaks from the pad pressure; although, for me, I can say the same about the V-Mode XS.  The clamping force does however provide a good on-ear seal that blocks out some amount of exterior sound.  Later I found that switching to the large headband provides a much more comfortable experience because of a lighter clamping force (more on this below).   As final note on on-ear comfort, the CL rectangular pads were noticeably softer, distributed pressures over a wider area, were more comfortable, and provided a slightly better seal than the XS.


    What I discovered with the CL is "placement matters".  On a recommendation from fellow Head-Fi'er MrNaturalAZ (thank you), I began to experiment with positioning the ear pads.  Once I realized I needed to position the ear pads lower to improve the treble response, I found the normal range of adjustment of the standard small headband limited my ability to position the ear pads properly.  I promptly switched to the second "large" headband which provided a twofold benefit. First, it allowed me lower the ear pads to an optimum position, and second, the large headband seems to have less clamping pressure. With the large band, I'm now able to wear the CL for a longer period of time before experiencing any discomfort.

    Note:  Anticipating the need for a wider range of adjustment, Harman Kardon conveniently provides two headbands with the CL - the standard "small" band and a second "large" band.  The underside of each band is marked with an "S" or "L" to differentiate between the two bands.

    Takeaway: The most comfortable position may not provide the best frequency response, and treble performance can be improved with proper ear pad placement.


    I mentioned at the outset that the tonal balance of the CL favors the mid-bass region and the highs are recessed.  When combined, the balance of these two regions leaves a midrange that sounds very warm; Some may feel excessively so, even to the point of sounding muted.  However, the upside of this tonal imbalance is I can listen to the CL for many hours without fatigue.  I found the CL to be a very forgiving headphone with music I previously found to be harsh.  Yes, the CL clearly has a colored sound signature and when listening you may find yourself increasing the volume level to extract a bit more detail.  But, if the balance is to your liking you might find the CL to be a very listenable headphone that can be had for a very attractive street price ($60-$80).  However, I'd like to again emphasize most of my time with the CL was spent listen to FLAC files from a PC feeding a GeekOut 450; although some time was also spent listening to streamed music via Pandora, which through the PC I found acceptable.  I feel this bares repeating because the CL connected directly to an iOS device with less than optimum amplification and low resolution music will likely result in a slightly darker less detailed sound.

    That being said, if your budget is targeting headphones at $200 or less, at its current street price, the CL should definitely be on your short list of headphones to audition. Why?  Because in addition to being reasonably priced, the Harman Kardon CL more importantly, passed my goose bump test.  By that I mean, with the CL, I can close my eyes, listen to a performance, and be transported to a place that is emotionally engaging.  One example of this would be Adele's performance, on the Live at the Royal Albert Hall recording, where she closed the evening with her hit Rolling in the Deep.  The power of Adele's voice combined with the energy of the crowd made for a most memorable event, and the CL, even with all its faults, is still able to convey the sense of excitement that filled the hall.  I only wish I could have been there to experience Adele's performance first hand.  In summary, the Harman Kardon CL is a very affordable option that provides just enough soul to make the second hand listening experience pleasantly enjoyable.

    Harman Kardon CL (now modded - see Addendum)
    AMD based PC
    Light Harmonic GeekOut 450 (v1.5 firmware)
    Benchmark Media DAC1 PRE (discontinued)

    Windows 7 Professional
    J.River Media Center v19 (FLAC player)

    Adele: Live at the Royal Albert Hall (XL Recordings)
    Igor Stravinsky, The Firebird - Finale: Tutti! Orchestral Sampler (Reference Recordings)
    Various Artists: Head-Fi and HDtracks presents Open Your Ears (David Chesky  & Head-Fi)
    Various Artists: Speak No Evil EP (Datsik: Murder Style Original Mix)

    Addendum (11/2014)
    Ear Pad Barrier Mod
    As I was about to complete this review, I was researching the competing P3 model from Bowers & Wilkins.  I watched, with great interest, Tyll Hertsens's review of the P3 because the Harman Kardon CL pads are very similar to those found on the P3.   In closing his review, Tyll remarked he believed the muted high frequency response of the P3 may be caused by the ear pad foam absorbing too much high frequency energy.

    Since I also felt the CL high-end was recessed and the pads were similar in construction to the P3 pads, I wanted to test Tyll's theory and create a barrier to reduce the amount of absorption from the foam.  For simplicity, I decided to fashion a ring to partially isolate the foam.  I experimented with few different materials (eg. masking tape and duct tape), but finally settled on a thin velcro like cable management material for the ring.  You may wish to experiment with other materials to tailor the sound to your liking.  To create the barrier rings, cut two small strips of the material (each approx. 4 3/4" x 1/4") then form each strip into a ring slightly larger than the circular opening of the pad.  To install the rings, remove both ear pads (which are magnetically attached), insert one ring into each ear pad, then replace the ear pads.  Because the material I choose is somewhat stiff, I found it necessary to reduce the thickness of the ring until I was able to achieve a comfortable ear pad seal.  You may need to slightly adjust the thickness of the ring up or down a bit to meet your needs. The actual modification is shown in the pictures below.  With the installation of this simple mod, there was an immediately noticeable impact on the sound signature.
    Barrier Ring:
    Before (without the ring):
    After (with the ring):
    The modded CL still has a warm balance, but vocals are less veiled, and now there's additional detail and high end sparkle that was lacking before the mod.  One additional benefit of this mod is I no longer need to re-position the ear pads for optimal sound.  With the mod, the most comfortable position also provides acceptable sound.  This mod doesn't cure all ills, but I found it to be an improvement over the stock pads.  This is a simple mod that anyone can perform that may (or may not) be to your liking.  The good thing about the mod is it's completely reversible.  I suggest all CL owners looking to extract a little more detail from their CLs, at least give the mod a try.
    1. View previous replies...
    2. jazzfan
      I have no experience with the HM5, so I'm unable to comment. I suspect the over-ear design of the HM5 will provide better isolation that the on-ear design of the HK CL. But again, I can't comment on the sound quality.
      jazzfan, Mar 3, 2015
    3. Davidtech
      Well thanks anyway for taking the time to reply :)
      Davidtech, Mar 3, 2015
    4. pataburd
      For me, the CL shine most with acoustic or purely vocal venues where the bass enhances rather than obtrudes.  Vocals are rendered with a real sense of life and breath.  I do not find the treble rolled off at all.  
      pataburd, May 20, 2015
  2. ixampano
    A Underestimated newcomer to the On-Ear category (Updated After burn Review)
    Written by ixampano
    Published Nov 18, 2013
    Pros - Great value/Price point, Stong bass, clear overall spectrum response
    Cons - Uncofortable, recessed mids, not ideal for some genres
    Hello, guys. Originaly I was going to buy some AKG K550, Sennheiser Momentum or Sony's MDR-1R... Unfortunately this weekend was "El Buen Fin" (the equivalent to US Black Friday in Mexico) and, when I went on Sunday to buy my headphones On Bestbuy the AKGs K550 were Out of stock </3. So I had to buy something else... After try many headphones, including: Sennheiser's Momentum, Sony's MDR-1R, Sennheiser's HD25, Pioneer's HDJ1500, some Dennons and other headphones. I Ended up buying the Harman/Kardon CL, Now I'll tell my first impressions after a full day of usage.
    After some use of full usage for a Couple of hours every day, they finally burned. Now I have a different opinion overall.
    Update: I forgot to mention, most of the albums are mp3 320KB, except Erotic Cakes and Six Degrees of Inner Turbulance, these are Flac 24/44KHZ
    This is the kind of Headphones you either love or hate aesthetically, and I gotta say it... I Love their style, very retro-ish mature style (IMO).
    Inside the box you'll get a pretty nice packing, it feels pretty "Premium". It doesn't have "premium" Accesories Though. You'll get the headphones itself (Dah), an Apple compatible cable of 1.4M long, and a secundary nice aluminion headbang for bigger than averange head and a nice synthetic leather carrying case (but is not on the "Portable" side of the spectrum).
    As I said, the packing feels kind of premium, but doesn't have quit the accesories to make it premium.
    This is where I have really strong feeling agains this Cans... For one, they are Really confortable for like the first 3 hours of use (in my case)... Now, if you wear glasses -like me-... Well, welcome to the mot%&fu&()& Hell!!. This headphones are really confortable with a really nice and strong grip to the head, BUT!! if you use glasses, prepare for a world of pain after the the first half an hour. They hurt me really bad after that, I hope that the time change that; I don't want to  chose between wearing glasses or headphones 7-7
    After 2 weeks of agony, they become heavenly confortable, no more pain, no more "Take off your glasses off if you will spend more than an hour with the headphones". They're just wonderful comfortable and I can wear them for HOURS without feeling uncomfortable

    Build Quality:
    Here's the Deal, guys... It kind of have "Premium" material, the aluminion build feel quite nice and not cheap at all, but!... little things, like the plastic back side of the headphones and a pretty light weight, doesn't make headphones feel that they're "build like a tank". They doesn't really feel cheap, but doesn't feel premium either.
    I bought the headphones for this other than the awesome looking style. I'll break this section into the kind of music I listen to, and then a general comparison against the headphones I tried.

    Well, I my listening goes something like this: 50% Metal! (especially progresive), 30% Jazz, 10% Classical music and 10% Hip-hop and Electro.
    I have a very mixup opinion with this headphones and metal related music.
    ...And Jutice For All by Metallica: Here's the deal, I love ...And Justice For All, but the Engineer that mixed the album didn't quite  love it, otherwise, this wouldn't be one of the worst mixed albums on the metal (mainstream) history. I mean the mix totally suck, the bass is unadible, the drums are so low you can barely heard them at all!, but that happens with every single headphone I've owned... The problem comes when You realize that, the CLs, Make it a lot worst!!. the strong and robust bass on the CL makes the Awful bass, even more awful. The tendency of the headphones for having recessed mids, makes even harder to listen to James's voice. Although, the crispy and granular highs that the CLs have, gives the guitar a nice little snappy/crispy tone is just not good in any other thing.
    Unfortunately this headphones makes me don't want to liste to ...And Justice For All ever again. I don't know if the headphones really bring the bad mix on the album to show, or if the flaws within the respone of the headphones are to blame.
    Six Degrees of Inner Turbulence by Dream Theater: Man... This album really shows how good this cans are on a more modern production environment. I heard synth, reverbs, overdubs were I didn't heard them before. With a more modern production with lots of overdubs, synth everywhere and the guitar amplifier without the bass and trebles cranked up to 11, this cans really shine. You can really appreciate Myung's awesome bass, the strong yet no lossy bass of the cans really brings a new level of "Heavyness" to this whole album, all without overtaking the mix. However, The recessed mids and crispy highs make LaBrie's voice more annoying than ever before. Aside from that minor issue, this headphones really brings a lot of life to this album, with all the synth sounding very granular and with character and the guitar having a nice snappy tone thanks to the crispy highs.
    Overall the big bass, recessed mids and crispy highs on this headphones DOESN'T HELP THE 80'S/EARLY 90'S METAL MIXES AT ALL, in exchange the more modern stuff and some old stuff with tons of synth and tenor singer really benefits from this cans. I have to add: Baritone singer such as Phil Asselmo, James Hetfield are really affected by the recessed mids. the kind of loss a little bit into the bass.
    Honestly, this pair being my first "good" headphones (I do not count Beats as "Good"),so I was unfamiliar with the burn process. The burn process took sometime, something among 100 to 150 hours. I thought it would take like 30 hours.
    The first think I noticed the changes was the bass, it became tighter and roll off a little bit. Then the mids...Man, this is actually a big noticeable change; the recessed mid are gone, they become full bright, clear cristal and bright mid, so different from the first time I listened to the headphones. I didn't think a simple burn could change the sound that much; is not huge, but it's really noticeable. The treble roll off quit a bit, making the headphone a little bit "Treble shy", but  I mainly listen to Early Thrash Metal... This is actually a plus for Early Metal.
    Overall, the after burn it's quite noticeable and makes the Early Thrash Metal a lot more enjoyable and fun to listen. Now I can listen to thinks like Anthrax, Exodus And Testament without the bassy guitar tones overtaking the entire mix and making everythings almost unaudible

    Erotic Cakes by Guthrie Govan: I cried when I first listen to this Album for the first time with this headphones, It already was my favorite album, but... This headphones makes never want to stop listen to it.
    It's awesome how great the CLs are with anything jazz related. The big and clear bass really help to listen to the BEAUTIFUL bass that the Jazz music usually have, the recessed mids really accentuated the jazzy cleans that otherwise would sound muddy and the crispy highs gives another dimension to the incredible beatiful solos of the entire album. Without vocals (This album it's instrumental) The recessed mids seems more like an advantage rather than a disadvantage.

    Metal Fatigue by Allan Holdsworth: Contrary to "Erotic Cakes" This have tons of synths. Basically, everything I said about "Erotic Cakes" but even better. The Crispy highs gives the Synth a very granular texture to the synths, some may say it's " a Nasal sound", but IMHO it gives them Character, a strong one :).
    Four Seasons by Antonio Vivaldi: This!! this is where this headphones really shine! I don't have anything bad to say on this department. The low brass sounds outstandig, robust, strong with tons of presens. The Stringed intruments doesn't lost any clarity even with outstanding huge sound that the low frequencies have on this headphones.
    If you ever have the chance to try this heaphones, please try them with classical music, then compare to 300$ headphones and you'll see how close this headphones are to many 300$ headphones :).

    Methaphorical Music by Nujabes:
    I'm kind of cheating here, because this album it's pretty jazz oriented and more than half of the entire album it's instrumental, but whatever.
    Again, like the Jazz section, the instrumental-chillax-Jazzy song sounds beatiful... However, the ones that are not instrumental suffer a lot; Nujabes was the kind of musician that used to put a lot of emphasis on the intrumental section and turn out the voice a little bit, this among the sound signature of the CLs, really make a bad, bad, bad mix for the rapping, the recessed mids (Again!) make the low-male voices dull and lossy, the bass take over the voice a lot...
    This implies another big improvement from the burn. The bass is not that strong and wild anymore and the mids are clearer, so basically, the bass doesn't overtakes the voices anymore. Just like Metal section, this is a big improve for the headphones after they burned

    Discovery by Daft Punk: Just like the Jazz and instrumental music in general, this is where the sound signature of the CLs make them worth the try at least. It totally blows out the water things like the Beat solo, Monster inspiration and even the Beats Pro (I used to own the beats solo,Pro and Tour... they all broke up in less than a year...).
    The all migthy, yet no lossy bass shines perfectly here, without taking away any other frecuencies, the bass it's might, robust and strong. This kind of music it's "the matchup" for this Headphones, no doubt about it. It has about everything a Electro lover likes: Style, great bass, and clear and balanced signature for other high frecuencies samples.
    Overall the bass on this headphones is big, strong and robust (You can quot me on this one :p) without being lossy and/or boosted the SH!$ out of it (I'm looking at you beats ¬_¬). The Recessed mid, however, CAN totally affect a whole spectrum of music, especially the kind of music that has a lot of low end (something among 80-240HZ), wich unfortunaly for me, was the favorite sprectrum for the 80's Metalheads to crank up to eleven, making the guitars sound really bassy and sometimes dull and lossy. The sightly boosted and crispy highs of the CLs could be either Awesome or disgusting, that's really a personal preference, some people might is "Nasal" and "Too Edgy", but I consider it Snappy and crispy with a unique character; it also favors A LOT Female singers and more modern guitar tones :).
    Overall, This headphones are on the "funny" side of the Headphones spectrum. They're flat enough to me to track things like guitars, bass, drums and vocals for my projects. but I wouldn't ever dare to mix something with this headphones. CLs are deafinetly not as good as something as the Momentum, yet they're close enough to make me belive the 150$+ that the Momentums are, are not worth it. if it was something amoung 30-50$ then, yeah... just get the Momentum. Everything else I tried yesterday (Aside from the Momentums) Were not better than the CLs IMHO, some were differents, others were worst. I tried some Dennons (I don't remember the model) that were like 350$ and they actually sounded worst, yeah the bass was huge and whatever, but they didn't have nearly as good clarity as the CLs
    IMHO this headphones deserve AT LEAST a try. I'm really liking this headphones and if Harman Kardon ever decides to get up something among 300$ to the market, I'll definetly give them a try :)

    So... The nasal treble is gone, instead becoming somewhat treble shy. The mids had the greatest improvement overall, becoming stronger and clearer. The awesome bass just became a little bit tighter and less wild.
    The confort it's so much better now, the headphones doesn't hurt me anymore...
    Overall the burn took a lot longer than what I expected, but it's so worth. It basically took away my two biggest complains with this headphones, making them so awesome and really high rated on my Price/Performance Ratio list :p
    My score in general for this headphones is 8/10... Now if I put a Score refering what I paid and what I get... It'd be: 9/10
    PS: I Hope that my "Spanglish" is good enough to make this pseudo-Review readable
    1. View previous replies...
    2. ixampano
      Thanks, bro!
      BTW, After burn updated :p
      ixampano, Dec 2, 2013
    3. csnr
      Thanks for the review. Just trying out a pair of these. First impression are that the low end is very underwhelming. The bass reaches low, but has no PRAT. But I love the way vocals and guitar sound. Will burn them in a bit more and listen again.
      csnr, Jun 3, 2014
    4. Davidtech
      How do you think these compair to the brainwavz hm5 ?
      Davidtech, Mar 1, 2015