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Just got this from John Massaria JM audio Edition. This is XTC ^2.5. I have to say It is the best closed back I have heard. Vocal sound buttery, widest sound stage for closed back, addictive, warm and yet detailed, punchy strong bass. I have neglected my Diana TC and Audeze LCD X ever since I have gotten this. Love it.. I asked for warm detail tuning. It is a beryllium. If you have various headphones you will be able to tell the difference on soundstage. Definitely this does not sound as wide as open back like my Abyss Diana TC which is very very wide sound stage. But on my subjective hearing of closed back, i personally feel XTC 2.5 is the best so far..I personally have tested many headphones like ZMF, Dan clark, Hifiman, Abyss etc.. hope it helps

Just got started listening to the xtc 2.5 and holy crap is this amazing. Just from a quick listen. The punch in the bass is great without being sloppy and bleeding into the low mids, and the vocals are amazing. It is such an amazing balance. -Janahn
Reviews: Video
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Owner from UK made six different graphics after buying the XTC^2.5 to show his excitement and appreciation for the tuning and build-
WOW how awesome is that?!

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XTC^2.5 Euphoric Xtreme Trip Limited Edition

Good Morning - It became a late night. As I was listening I was trying to figure out why the sound was so intoxicating and how to describe it. Then it struck me that it’s like putting a pair of Marten speakers on your head. I switched back and forth between the two and sure enough the sound signature is almost identical. Particularly in the lower end where so many headphones, and even speakers, seem to struggle. Big, rich and tight. Quite a feat seeing that the Marten’s use 8” woofers. Two masters at work. Thank you!

- BB Chicago, Illinois 8-22-23

Canada 9-21-23 XTC^2.1

Hey John,


I picked up the XTC^2 yesterday from the post office and I've been giving them a listen since I picked them up. These are really great so far and I'm enjoying their sound signature. I've also noticed the bass is coming in more and more as my ears adjust to them and the drivers break in further!


As you said these do sound fantastic and they do live up to my expectations of them! I've decided to go with the fuzzy pads on them since they just feel so nice and comfortable.


Thanks again for setting me up with a fantastic pair of closed back headphones!

-Jon From Canada 

Reviews: Image

ardbeg1975 said: I also just got back my GH upgraded to “Mk2” by @John Massaria whom I’d also like to personally thank for his sonic surgery. I’ve been listening to the Mk2 for the past day and I’m very impressed particularly in comparison with my VCs. I’ve been running the Mk2 and the VC on a Tor Audio Balanced transformer coupled tube amp (1980s-era Soviet tubes) and a Flux FA-22 SS amp, both fed by an up-sampled 8X stream from Qobuz via Roon to HQPlayer to Zen Stream to Qutest. Bass — Just Awesome. The bass on the JM edition was already very enjoyable but I echo the earlier comments that the imaging and sound staging are improved over the original. The VCs are still more visceral but the Mk2 seems to perfectly capture the middle ground of the bass presence and dynamic rumble of the VC and the imaging / separation precision and control of the Rögnir. Kick drums in particular are just great. Midrange — I dare say Mk2 is giving the VC a contest here as well. VCs may still be a touch better in timbre but particularly on the Flux, the Mk2 is exceeding the VC in depth of sound-stage for the vocals so it may come down to whether you prefer that “closer to the stage/vocalist” feel or not. I give the Mk2 the edge in vocal imaging and separation precision on many of the tracks with which I tested. The two HPs are trading blows depending on the track in width of sound stage. I may give the Mk2 the slight win in pure width but the VC the win in holographic effect. Call it a tie overall. (Side note — I took the extremes and tested with High on Fire’s Art of Self Defense, a very sludgy album, and with Khruangbin’s Con Todo El Mundo, a very articulated album.)  Treble — Smooth and non-fatiguing on both the Mk2 and VC. I’d give the VCs the edge here in timbre and detail retrieval, particularly on the metallic reverb of cymbals, but not by much. Overall, the GH JM Mk2 is holding its own against one of the best closed back dynamics in the VCs and doing so at circa half the price. @John Massaria you aren’t charging enough for this mod.


After I shipped back the newly modded JMk2 back to the owner I was concerned so I wrote- "If you aren’t amazed on the mod send em back I’ll do what ever to try to make it how you like"

The new owner of the Mk2 said: "I don’t think that I will be sending them back! The soundscape and layering remind me of those of ZMF Atrium! And these are closed-backs! amazing! listening: fantastic! The virtues of the pre-modded GH50 JME with added strengths !! I will be commenting in the Kennerton thread with more crystalline observations " - jonathan c


A lot of people ask, "What's the turn around time for JM Fractal total mod?" the answer: typically a day or two ...

just email me it's easy!

I hope you give me chance! -JM

Reviews: Testimonials
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