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  • All new ground up redesign of the Hydra. Precision engineered from Aluminium for a perfectly balanced IEM

Recent Reviews

  1. Brooko
    RockJaw Hydra – Bass, Bass, Bass
    Written by Brooko
    Published Jan 9, 2015
    Pros - Very good build, nice fit, mobile enabled cable, aesthetics (looks), mid-range, very good warranty (3 year)
    Cons - Too much bass – overshadows rest of frequency range
    For larger views of any of the photos (1200 x 800) - please click on the individual images


    I’ve been working with RockJaw UK for the last 12 months giving feedback on their IEM line, and providing reviews as they get to release point. So it was with great pleasure that I received a courier pack from Bob containing not only the Hydra V2, but also the Kommand and Arcana V2. I’ll be reviewing both in the near future.

    The original Hydra I first tried (a year ago), I didn’t end up reviewing in the end – as the sound signature was extremely dark, bassy, and claustrophobic. The new version is sadly (IMO) similar to the original – but I need to acknowledge that it is tuned that way for a particular audience, and their tastes are completely opposite to what I personally value in an IEM.

    I still wanted to post a review though – because although the Hydra V2 doesn’t meet my personal tastes, it does have strong points which some will value.

    For those who aren’t aware, RockJaw is an English based audio company which although relatively new to the Head-Fi scene, has already released four IEMs and a full sized headphone. RockJaw’s service and communication in that time has been exemplary, and I really like how they have been interacting with this community to develop their product range.

    RockJaw’s philosophy (http://www.RockJawaudio.com/our-story/) is that really good sound shouldn’t be unaffordable, and build quality can be obtained even at budget friendly pricing. A fantastic example of this is their Alfa Genus (http://www.head-fi.org/products/rock-jaw-alfa-genus/reviews/11243) IEM which I still believe is one of the best and most versatile IEMs at its intended price point.

    The Hydras arrived almost 3 weeks ago, and because they aren’t to my sonic tastes I haven’t used them as much as I would normally do when reviewing a new IEM (preferring to spend extra time with the Arcana 2). I have clocked up around 10-12 hours with them so far though.

    It has been an interesting experience as there are some parts of the Hydra I do like, but much I do not. Read on to find out my personal thoughts on the Hydra 2 and who they might be ideal for.


    I was provided the Hydra V2 as a review unit from RockJaw. I am in no way affiliated with RockJaw - and this review is my subjective opinion of the Hydra V2. I do want to take this opportunity to thank Bob though – he exemplifies RockJaw’s excellence in customer care in every communication we have.

    PREAMBLE - 'ABOUT ME'. (or a base-line for interpreting my thoughts and bias)

    I'm a 47 year old music lover. I don't say audiophile – I just love my music. Over the last couple of years, I have slowly changed from cheaper listening set-ups to my current set-up. I vary my listening from portable (Fiio X5, X1 and iPhone 5S) to my desk-top's set-up (PC > coax > NFB-12 > LD MKIV > HP). I also use a portable set-up at work – either X5/X1 > HP, or PC > Beyer A200p > HP. My main full sized headphones at the time of writing are the Beyer T1 and Sennheiser HD600. Most of my portable listening is done with IEMs - and up till now it has mainly been with the Fidue A83 or A81, Dunu DN-1000 and Altone200. A full list of the gear I have owned (past and present is listed in my Head-Fi profile).

    I have very eclectic music tastes listening to a variety from classical/opera and jazz, to grunge and general rock. I listen to a lot of blues, jazz, folk music, classic rock, indie and alternative rock. I am particularly fond of female vocals. I generally tend toward cans that are relatively neutral/balanced, but I do have a fondness for clarity, and suspect I might have slight ‘treble-head’ preferences. I am not treble sensitive (at all), and in the past have really enjoyed headphones like the K701, SR325i, and of course the T1 and DT880.

    I have extensively tested myself (abx) and I find aac256 or higher completely transparent. I do use exclusively redbook 16/44.1 if space is not an issue. All of my music is legally purchased (mostly CD – the rest FLAC purchased on-line).

    I tend to be sceptical about audiophile ‘claims’, don’t generally believe in burn-in, have never heard a difference with different cables, and would rather test myself blind on perceived differences. I am not a ‘golden eared listener’. I suffer from mild tinnitus, and at 47, my hearing is less than perfect.

    For the purposes of this review - I used the RockJaw Hydra straight from the headphone-out socket of my iPhone 5S, X5, and X1. I also used my Beyer A200p and also the E11K amplifier, but IMO they do not benefit from additional amplification. In the time I have spent with the Hydra, I have noticed no change to the overall sonic presentation (break-in), but am aware that I am becoming more used to their signature as I use them more often (brain burn-in).

    This is a purely subjective review - my gear, my ears, and my experience. Please take it all with a grain of salt - especially if it does not match your own experience.



    hydra01.jpg hydra02.jpg

    Front of retail sleeve

    Rear of retail sleeve

    The Hydra V2 arrived in RockJaw’s new retail packaging, which consists of retail sleeve (windowed front and back). When the outer sleeve is removed, it reveals a foam insert holding the IEMs and tips, and hinged lower compartment containing shirt clip, manual, and carry pouch. The packaging is solid, easy to handle, and IMO looks really nice (I personally love the slate, grey and orange combination).

    hydra03.jpg hydra04.jpg

    Sleeve and inner

    Inside the compartment - carry pouch and clip

    The included carry pouch is essentially a draw string felt type bag – but it appears well made and is ideal for carry the Hydras in your pocket. It won’t offer a great deal of protection, but given the very good build quality, it should be sufficient and is appreciated as a great solution for avoiding cable disarray.

    hydra05.jpg hydra06.jpg

    Hydra IEMs and accessories

    Tips in profile

    The accessory pack includes 4 pairs (S,M x2, and L) single flange silicone tips, and a shirt clip. Fairly frugal – but considering the price point, understandable.

    (From RockJaw)
    Single dynamic driver inner ear monitor
    8mm dynamic driver
    Frequency Range
    20 Hz – 20 Khz
    16 ohm
    108 dB +/- 3dB
    3.5mm gold plated, right angled
    1.2m twisted and sheathed, and includes inline mic + button control
    IEM Shell
    Bullet shape, aluminium


    At the time of writing, I do not have a frequency graph – but at a guess I would suggest a very large hump in the lower frequencies, recession in lower mids, and small bump in upper mids, and larger bump in lower treble.


    The Hydra V2 has a very light weight all aluminium shell in a bullet cartridge type shape. It measures 10mm in diameter at the base, and has a length of 18mm from bass to nozzle tip.

    hydra11.jpg hydra10.jpg

    Full metal chassis - very well built

    Rear port

    The colour is (IMO) a very attractive dark chocolate brown with silver accenting/striping. The body is micro-grooved in circles, and the RockJaw name and L/R indicator are very clear to read (silver on brown). There is a large vent/port at the rear of the Hydra, the nozzle has a generous lip, and is also meshed to protect the driver. There is generous strain relief.

    hydra12.jpg hydra13.jpg

    Knurling can be seen (may need to click image) - note tapered nozzle

    Good strain relief, and nozzle has mesh to keep nozzle clean

    The cable is brilliant, and I wish more manufacturers would adopt something similar. It is a twisted pair encased in a smooth flexible plastic sheath which is very pliable, very non-microphonic, and appears to be very strong.

    From the left earpiece there is a combined mic and single button control device (1 click pause/play, 2 fast clicks track +1, 3 fast clicks, track -1). This hangs (when worn over ear) about half-way between my jaw and shirt collar. The microphone is a good for audio and in my testing voice came through loud and clear. For those preferring a chin slider/cinch, the mic unit is the reason it is missing – but a shirt clip is included instead.

    hydra07.jpg hydra08.jpg hydra09.jpg

    90 degree plug

    Y split

    Microphone/button control

    The Y-split is very generic / no frills, but has reasonable strain relief at the single exit. The jack is right angled, 4 pole, very slim (ideal for smartphones with cases) and at my preferred 90 degree angle.

    Overall the build quality is an extremely good standard for the cost. I can’t really fault them at all.


    I have one ear canal slightly different to the other one (my right is very slightly smaller) - so I tend to find that usually single silicon flanges don't fit overly well. I initially tried the included large silicone tips, and whilst they fit OK, I was unable to maintain a seal. So I reverted to a slightly wider set of single flange silicone tips of my own which also have a very wide bore – which seems to help with the Hydra’s very dark tonality. I did try Comply tips – but these further dampened the treble that was there, so I stuck with the silicones.

    Comfort is very good and they are very light weight, easy to fit (once you have the right tips), and also fit quite flat to my ears – so can be worn lying on my side. The Hydra can be worn cable over ear or cable down.

    Isolation with a good insertion and correct seal was average for an IEM, mainly due to the rear exterior port. With music playing, most ambient noise is well and truly filtered out. I’m not sure if these would be my choice for a long haul flight though.

    So how does the Hydra V2 sound?


    The following is what I hear from the Hydra V2. YMMV – and probably will – as my tastes are likely different to yours (read the preamble I gave earlier for a baseline). Most of the testing at this point (without EQ) was done with my Fiio X5 as source, no EQ, and silicone tips with a wide bore. I also (as a contrast through the review) used my iPhone 5S with Accudio Pro EQ applied (CX300 preset) to remove a lot of the mid and sub-bass.


    Test equipment - X5, X1 and Hydras with wide bore silicones

    Tracks used were across a variety of genres – and can be viewed in this list http://www.head-fi.org/a/brookos-test-tracks.

    Thoughts on General Signature

    If I was to describe the default signature in a few words – I’d choose the words “dark”, “bassy” and “veiled”. Using the EQ’d iPhone, it becomes “warm” and “smooth”.

    The Hydra V2 has likely been tuned towards the modern day generic young consumer who prefers a very bass heavy sound. I’m perfectly OK with that – although it is literally a million miles from my idea of a good signature. The problem I have with it is that although there is a nice mid-range lurking there, and a tiny bit of sizzle in the lower to mid treble, it is pretty much masked by the overpowering bass. And the bass unfortunately bleeds well into the mid-range, and makes the vast majority of my music utterly lifeless – with no dynamics or contrast.

    Overall Detail / Clarity

    For this I always use both Steely Dan’s “Gaucho” and Dire Strait’s “Sultans of Swing” as there is a lot of micro detail in both tracks, and the recording quality for both is excellent.

    X5 (no EQ) - with Gaucho, the sax intro is there but in the background behind the bass guitar (it shouldn’t be). Vocals are there, very smooth, but also almost muffled – none of the timbre that I am used to is there. I can’t really hear cymbals or high hats coming through at all – just very faintly in the background. Overall just a very dark presentation. I am missing virtually all of the upper end sparkle that makes this track magic. There just isn’t enough contrast.

    iP5S (bass EQ’d down) – it’s like I’m hearing the same track with a veil removed. It is still warmer than I’d prefer, but now vocals are more forward, and the mid-range is allowed to shine. Bass is punchy without being totally over bearing. Some of the upper detail is more apparent – but it still is subdued compared to my favourite IEMs.

    With Sultans of Swing, it was a repeat of the above notes. With no EQ, the normal magic is missing for me. With EQ the track comes to life.

    Sound-stage & Imaging

    For this I use Amber Rubarth’s binaural recording “Tundra”. I use this because it’s a pretty simple way to get comparative data on sound-stage.

    It’s usually difficult to get a reasonable stage size from an inner ear monitor. The stage is often quite small / close – with an average impression of space. The Hydra has a small intimate stage (by default) with this track, and although there is some directional imaging, the sense of space is not expansive, and the overall stage is diffuse and cloudy. The direction is there, but the pinpoint accuracy isn’t.

    Loreena McKennitt’s “Dante’s Prayer” was also quite dark and very close (intimate). Sadly Loreena’s vocals came through quite muffled, and if I didn’t know the lyrics intimately I would have had trouble deciphering them I think. Cello and piano were both quite good – but no magic for me.

    Bass Quality and Quantity

    I’m usually used to hearing some quite impactful and good quality bass with the recent triple hybrid IEMs I’ve been spending time with lately – but the bass from the Hydra was simply too much for my preferences. It definitely has copious amounts of both sub and mid-bass, but its problem (to me anyway) is that the decay is quite slow, and the bass bloom and overall warmth detracts from the mid-range it obviously possesses (revealed through EQ).
    Amongst my test tracks is “Muddy Waters” by Mark Lanegan. This blues rock track is quite dark and brooding anyway – and the while Hydra really had a huge amount of impact, Mark’s vocals were almost distant. The whole track is too smooth and dark for my personal preferences. Applying EQ via the iP5S had the same sub-bass impact coming through (nice) but this time I had no issues hearing Mark, and even getting some of the texture of his voice. This presentation was actually very good, and does show what the driver is capable of.

    Female Vocals – A Special Note

    I have added this section simply because around 60-65% of my music revolves around female vocals – be it jazz, pop, rock, electronic, or even opera. I’m an unabashed fan. For me the sign of a successful IEM is how successfully it conveys emotion and timbre with my female vocalists. Other IEMs I’ve owned in the past had sometimes struggled with some of the artists I like – and this includes IEM’s like Shure’s SE535 LE (upper-mids on the SE535 LE are quite forward).

    By now I wasn’t expecting great things from the Hydra – but thought the upper mid-range bump it has might perform well (possibly with EQ). One of my early litmus tests is usually queuing Agnes Obel – as some of her recordings can become quite strident or shouty if the mids aren’t quite right. With the Hydra her vocals weren’t euphonic at all, and the whole track sounded as if it was being sung in a tunnel – hollow and boomy. With EQ’d iP5S it was much better. The vocals were allowed to shine and the sense of claustrophobia was gone. Still quite warm, but I could live with this. The cello also shows promising signs – with good timbre and tone.

    I then proceeded to play my normal medley of other tracks from artists including Christina Perri, Gabriella Cilmi, Florence and the Machine, Feist, and Norah Jones. The Hydra can handle vocals nicely when EQ’d – but I would not recommend its default tuning for any of my female artists so far.

    Male Vocals

    At the other end of the scale sits a lot of my rock tracks.

    Kicking off with 3 Doors Down “Away from the Sun”, and the vocal presentation is OK – it just doesn’t have the contrast and sparkle I’m used to in the music. Moving to Green Day, and once again the music is presented “OK”, it just too warm, no contrast, uninvolving. Plenty of bass though – and what is there is boomy. Rather than go through track by track, band by band – easier to skip to my litmus test – Pearl Jam. Compared to everything else I’ve heard so far, this is actually an improvement comparatively – but there is still no life in the track for me. Time to queue up Vedder on the iP5S (EQ’d) – and now this is really pleasant. My personal preference would be a little more detail – but I could listen to this for an afternoon with no issues. Cymbals are now easy to hear, and Vedder’s voice has emotion.

    Genre Specific Notes

    Again for tracks, albums, artists – please refer to this list: http://www.head-fi.org/a/brookos-test-tracks

    Normally I’d go through this section track by track, genre by genre – but I’d rather keep this short, as the same issues I’ve mentioned above continue to display themselves with most of the music I’ve tested the Hydras with. So for now I’m going to quickly summarise ….

    Rock, Alt Rock, Jazz, Blues (apart from Beth Hart’s Paradiso album which is recorded very hot), and especially Classical and Opera all sounded dull, flat, almost toneless with the default signature. Rap was actually OK, and depending on the track, the Hydra rendered some Pop and some EDM as OK. True hardcore bass-heads may enjoy the impact with a lot of EDM and Trance.

    Introducing EQ (major bass reduction) turned the Hydras into a different headphone though, and one I could happily live with – although it still would not be to my real preferences.


    I covered this in the introduction – but the Hydra definitely doesn’t need any extra amplification. It was easily powered out of all my portable devices, and with the X5 I rarely go above 30/120 in terms of volume.


    I read back my notes and what I’d typed so far, and I almost feel guilty as it does come across as rather negative. The Hydra V2 is not a terrible IEM per se – its default sound signature is just the antithesis of everything I personally look for in an IEM.

    Looking at the good points (IMO), the Hydra has a wonderful build and aesthetics, very good cable, fits nicely, and is both light weight and looks to be very durable. Sonically (especially after EQ), the Hydra possesses quite a nice consumer friendly mid-range and enough sparkle to convey detail without harshness or brittleness.

    The issue for me is the default signature. The bass is over-powering, and almost claustrophobic in its effect on many of my tracks. For me personally – being used to brighter, more detailed earphones, it is like having a wall between myself and the musicians playing.

    The RockJaw Hydra V2 could suit:

    1. Fans of Rap, Pop and EDM who like a warm and extremely bass heavy presentation
    2. People who are severely treble sensitive
    3. People who like a warm dark signature

    The RockJaw Hydra V2 is unlikely to suit anyone who looks for:

    1. Good contrast
    2. A high level of detail
    3. Good balance across the frequency

    The question is now how to grade this. The Hydra is clearly not intended for the audio demographic I reside in – but for mainstream younger consumers, it may well be exactly what they are after. Today I’m giving these 3 stars – based on the build, and the capability if EQ’d. I’d actually drop this to 2.5 stars if I could – but that comes out to a negative review on Head-Fi’s system, and of anything I’d like to record my review as neutral rather than negative. These (as the English say) are simply not my cup of tea.

    Thanks once again to Bob and the RockJaw team for giving me this opportunity.

      H20Fidelity likes this.
  2. mark2410
    ROCK JAW Hydra V2 Quick Review by mark2410
    Written by mark2410
    Published Dec 3, 2014
    Pros - Chavtastic mountain of bass. Great technical ability.
    Cons - Tuned with Beats fans in mind.
    ROCK JAW Hydra V2 Quick Review
    Thanks to ROCK JAW for the sample.
    Full review here http://www.head-fi.org/t/744853/rock-jaw-hydra-v2-review-by-mark2410
    Brief:  Oodles of bass.
    Price:  £40 or about US$63 though I could not find in the US.
    Specification:  Drivers: 8mm dynamic, Impedance: 16Ω, Sensitivity: 108+/-3db, Frequency response: 20 – 20000Hz, Cord Length: 1.2M, Jack type: Gold plated 3.5mm, MIC with pause/play button – (iOS & Android compatible)
    Accessories:  3 pairs of tips and a little baggy.
    Build Quality:  Very nice.  I’m generally a fan of braided and wrapped cables and the buds seem solidly constructed too.
    Isolation:  Really rather good for a dynamic.  Perhaps even just enough for the odd flight or Tube commute and naturally easily more than enough to get yourself run over.  Do look where you’re going people.
    Comfort/Fit:  Great.  Despite being quite sealed and dynamic it was above in ears and done.  Comfy to wear for ages too.
    Aesthetics:  Meh, there is nothing wrong with them but they don’t provoke any great desire either. 
    Sound:  BASS.  While I know from the spec its likely they are the exact same driver as in the Arcana V2 but……..the tuning here is so slanted to the bass.  The bass simply is sufficiently dominating as to just get on my ****.  I know that the mids are a good quality and the highs are nicely nuanced but god, that bass will just not bugger off.  In smallish doses I could see some appeal in its weighty bass but in too many tracks I found it was just getting in the way of the bits I wanted to pay attention to.  The detail levels though are high like its sibling which makes it all the more maddening.  In strictly technical terms the driver in here is excellent and has excellent abilities for this.  I know that it’s technically good but that it cost the same as its sibling, unless your some crazed bass junkie I’m struggling to see why you would go with this one.  It’s like being presented with a beautifully prepared steak and then someone puts ketchup and one of those “cheese” slices on it.  I know there is greatness in there but it has been tailored to a certain demographic.  By certain demographic I mean people who think Beats are the height of audio quality.  Perhaps a better description would be like taking something wonderful, and then wrapping it in Burberry.  It may at its core still be that wonderful something but it’s just really hard to get past how it’s been tailored, sometimes just one issue can be a real show stopper.
    If course if you love a mountain of bass and think Burberry is the height of good taste then by all means knock yourself out, it could well be the IEM for you.
    Value:  Great if you want a bass cannon.  Otherwise I’d pick its sibling every time.
    Pro’s:   Chavtastic mountain of bass. Great technical ability.
    Con’s:  Tuned with Beats fans in mind.


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