Stefan AudioArt HD800/800S Ultra-Modification

Rated 5.00 out of 5 based on 1 customer rating
(3 customer reviews)



Our new Ultra-Modification for the Sennheiser HD800 Headphones with the Endorphin Hardwired or Connector Version High-End Headphone Cable will expose the listener to the purest most spacious headphone experience available. Our HD800 Ultra-Mod/Endorphin headphone cable combination elevates the presentation of the great Sennheiser sonic signature to a new level that will exceed your highest expectations.

Stefan AudioArt’s headphone modifications are based on James Serdechny 35 years of experience as an engineer and musician. By removing or replacing key parts of the assembly of the HD800 headphones the issue of vibration control is properly address and the result is a headphone which performs at a significantly higher level. Every headphone mod we’ve come across on the market has been created by DIY individuals who operate on misguided notions. Their approach to adding materials to a headphone comes from their lack of knowledge of headphone design and the result yields degradation in the performance of the headphone which can be easily heard in a headphone system setup with properly designed cables and vibration control.

Key original internal and external parts of the HD800 headphones inhibit, distort and close-in the sound. The HD800 Ultra-mod is a proprietary process which entails removing specific parts from the stock HD800’s internal and external assembly, treating and remounting the drivers for optimal vibration control and replacing the driver mounting configuration with a Stefan AudioArt proprietary system.


More information coming soon.

For questions regarding the HD800 Ultra-Mod please call 860-521-2563 or send an email to


  1. Michael S. says:

    James, just a quick “second impression” re sound. I’ve been leaving the ‘phones on “burn-in” mode (Track 9 of the XLO CD) overnight and then listening for real for about an hour each evening. I find it difficult to believe there are the same headphones that I sent to you just a few weeks ago! I’m hearing SO much more into recordings I know well — it’s quite wonderful! I don’t know how much of what I’m hearing is from the HD800 headphone Ultra-Mod and how much is from the Hardwired Endorphin Headphone Cable, but it’s academic, I suppose. The overall effect is — WOW! And for the record, this is still just with digital playback — I can’t imagine what will happen once the analog from rig is back on-line!

  2. I wanted to tell you that yesterday I went to a friend’s house who bought the new Focal Utopia, and I decided to bring my modded Senns with me. I was really amazed to listen to them side by side (Utopia and modded HD800), and it was amazing how my modded HD800 blew the Utopias away in every level. The sound was much more transparent, more neutral, quicker and with much better detail. And we’re talking about a $4,000 model.

    My friend also had a stock HD800, which I also tried, and they were even worse than the Utopia. Strange as it may seem, all this time I had never had the chance to compare my Senns modded by you, with the stock ones. I guess it’s fair to say that the stock Utopia beat the stock HD800, but none of them comes close in its stock form to the HD800 modded by you with the endorphin hard-wired.

  3. Yes,the HD800S modification is reversible if I don’t like it.

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