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.
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.
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