[msing539]

For anyone unfamiliar with @John Massaria, the refined Kennerton Gjallahorn JM Edition carries his initials, as one of the first owners who modified those headphones. So when John posted this Drop x Hifiman R7DX in classifieds, I jumped on it right away.

The following are some shots of the mod taken from John's ad:

Though I haven't heard the stock R7DX, I would describe the presentation of these modded versions as overall wide and holographic, especially for a closed back. These rival the width on some Fostex closed backs, for comparison. Unlike most Fostex headphones, however, the mids here are nice and full. The low end on the JM is well controlled, articulate, and feels surprisingly fast--even on more complicated tracks. And the upper mids/treble are natural and lively without ever becoming harsh or fatiguing. These could easily be considered endgame headphones for anyone looking to spend under $300.

The modifications were fairly extensive, and mostly achieved with different types of adhesive foam, fabrics, and a fractal fiberglass mesh. According to John, the mesh helps reflect and refract frequencies without muting certain frequencies. I would say in their current state, these $150 headphones rival many in the sub $1000 range for overall clarity, soundstage width/height, and dynamics.

I'm betting these will become cult classics one day as John continues to mod different headphones with new techniques.

 

[wenbinbin2010]

I believe I'm now the 2nd person to own one of JMs modded HE-R7DX closed backs, and I feel incredibly fortunate! Original FS link here for the 2nd unit, which per the listing has slightly different (improved?) mods compared to the 1st modded unit: https://www.head-fi.org/classifieds/hifiman-he-r7dx-drop-jm-mod-closed-back-modded-by-jm.24813/

I'll be very honest in saying I'm not the best reviewer for audio, despite having quite extensive experience with many headphones and chains over the years. But I have to say, I am very impressed by a $150 modded headphone, sounding this good. The simplest comparison I can give...I am totally satisfied listening to this headphone (without any EQ), straight out of a Lotoo Paw S1 from my iPhone, and this is coming from typically listening to a Susvara on a high end SS amp, or a Verite Open on a high end tube amp. For some qualities, this modded HE-R7DX is better than either the Susvara or the Verite Open (seriously!). Maybe it has to do with the closed-back nature, but it is incredibly "punchy". I don't think I ever understood what punchy meant until this pair of closed-backs. I feel like the dynamic drivers are literally beating like a drum or a piston, something about this driver with the mods makes music physically palpable. The soundstage is quite impressive too for a closed back. No immediate qualms with the treble, which I typically have issues with (often have to EQ down the treble for headphones like my prior HE1000 or even the Auteur). The treble is not harsh, not sibilant, not unnatural sounding. Adequately detailed. Mids are not "magical" like the Susvara, but again nothing to fault, they sound good, not recessed. The bass is punchy as described previously, I don't think the sub-bass is incredibly deep or "rumbly", but the overall punchiness makes up for this.

I'm sure the Susvara and Verite will still sound "better" when I switch back to them, but the MRSP of the Susvara is 40x the price of the HE-R7DX, not even including the chain the Susvara requires. I've had my fair share of closed backs too. I really loved the Eikon and Atticus, being a fan of the ZMF house sound. The Verite Closed was good, but I preferred the VO. I thought the clearance sale Focal Elegia was good technically for the price, but really required EQ to sound pleasant for casual listening. Again, all those are much more expensive, bulkier, heavier.

@John Massaria Thank you so much for releasing these into the wild! The cups of the R7DX remind of the wireless Devas, so I wonder if there would be any way to install the R2R Bluetooth attachment into the R7DX. A wireless version of these modded R7DX closed-backs...that would be amazing.

 

[msing539]

Thanks very much for the very kind words - I do plan on releasing more of these but very limited one a week or so so others can enjoy this kind of tuning under $200 - that rival headphones costing much higher amounts - and I love how comfortable they are - do light and easy to work with and not bad looking either - thanks again I enjoy working on things like this making them better than o found em- JM

John, are they numbered somewhere? If not, could they be?

 

[subguy812]

It appears mine should arrive tomorrow.

 

[subguy812]

 

[subguy812]

John... fantastic job. These sound impressive. Will write specifics later.

Thank you

 

[ardbeg1975]

I don’t know what number I am but, as a hardcore fan of @John Massaria’s work (I own three modded Kennertons), when he pinged me regarding my interest in a modded Hifiman closed back, I immediately said yes. Like others in this thread, I have no experience with the stock version of the HE-R7DX but the bass extension is excellent with healthy impact. Mids and treble are very clear and detailed. Imaging is also very good. Soundstage does not have the same huge expansiveness and depth of his Kennerton GH50 JME mark 2 or Rögnir planar mods but it is not claustrophobic by any means. My only quibbles would be some minor timbral issues (particularly with some strings and cymbal crashes) and some sibilance with certain vocals but that is more the driver than anything else. Certainly sounds like a solid $500-$750 category headphone overall and much better than that in certain aspects like mid clarity and bass extension. Thank you again John for all you do.

 

[snapple10]

Another lucky owner here. So, grateful for this opportunity. Got it and set up but haven't been able to listen to it yet
Wanted to say a big thanks to JM

 

[DeweyCH]

Got a pair myself. I’ve looked to John’s mods for a lot of my own design inspiration and these are pretty fantastic, although I haven’t had that much had time with them since they arrived yesterday.

 

[ardbeg1975]

So is this headphone’s (un)official title now “Hifiman HE-R7DX JM OCD Edition”? I should get mine by next week.

 

[snapple10]

I did exactly that, bought stock to compare. I much prefer the JM mod. I am unable to convey what I hear with gears but JD mod sounds less resonant , more body
JD if you want a stock pair to mod, I got one

 

[snapple10]

I stopped comparing to stock and really enjoying this little gem. Easy to drive, fit has been significantly improved and natural sounding, perfect for long sessions

 

[ardbeg1975]

I don’t know what number I am but, as a hardcore fan of @John Massaria’s work (I own three modded Kennertons), when he pinged me regarding my interest in a modded Hifiman closed back, I immediately said yes. Like others in this thread, I have no experience with the stock version of the HE-R7DX but the bass extension is excellent with healthy impact. Mids and treble are very clear and detailed. Imaging is also very good. Soundstage does not have the same huge expansiveness and depth of his Kennerton GH50 JME mark 2 or Rögnir planar mods but it is not claustrophobic by any means. My only quibbles would be some minor timbral issues (particularly with some strings and cymbal crashes) and some sibilance with certain vocals but that is more the driver than anything else. Certainly sounds like a solid $500-$750 category headphone overall and much better than that in certain aspects like mid clarity and bass extension. Thank you again John for all you do.

Having given my impressions above on JM’s first round of R7 mods, I recently received the “OCD Extreme Stealth Edition” updated version. This newest iteration is definitely an improvement on the last round of mods. The aforementioned sibilance and timbral issues are now barely noticeable, extension and clarity across frequency range remain excellent, and width has also improved. Very good macro dynamics. Definitely punching 3-5X above its stock price tier in performance.

 

[BuddhistFoolish]

Hey Everyone,

Another new owner of the OCD Extreme Version of JM's Modded R7 here. Although I haven't had the chance to get quite into the weeds with it as I'd like, here are some initial impressions.

Reminder-This is a $150 HP at stock.

Soundstage: Absolutely blows my other closed back headphones out of the water (177X Go, Fostex Ebony), and creates a true psychoacoustic illusion of soundstage between its cup and your ear. Trades blows equally with my absolute favorite open back, the Philphone.

Bass: The Bass on the JM R7 is dynamic and well controlled. If the track calls for the subtle backing plucks of an upright bass, then this headphone delivers and if you need the THUMP of something like an orchestral bass drum or taiko drum, then the R7 is gonna give it to ya. Handles my rock library like a champ.

Mids: The mids are clear and sound natural to my ear. No one section seemed to get undue attention or step out, and the headphones seem to give even hand to both male and female vocals. They sound intimate in the best way.

Treble: Treble has the right amount of sparkle without hitting sibilance and easily matches wits with my more expensive headphones, some of which are three to four times the price of this one.

Control: Above all else, this headphone manages it's entire frequency range with an astonishing level of control way above its price bracket.

Hats off to John Massaria for taking a $150 headphone and elevating it to end game territory

 

[Pansbjorne]

Got my hands on some stock R7s for comparison.

The modded version sounds noticeably easier to drive; very interesting