My HD6XX arrived last week (24th July order), I've been listening to it over the weekend and comparing it to my HD600. It's not what I expected. A few years ago when I listened to a HD650 on a Schiit Lyr, my initial impression was it was quite different to my HD600 at home but was in the "side-step" ballpark. But now, listening to my HD6XX against my HD600 side-by-side, I've realised the difference is massive, well at least to my ears.
The only thing similar (but not identical) about these two headphones is the overall signature, or in a way, their tonal balance. However the HD6XX is just more refined in every way, I know Sennheiser didn't intend it to be a direct replacement to the HD600, but it sure sounds like one! The most immediate impression when I compared the two headphones is the obviously larger soundstage (or headstage if you will) on the HD6XX, in both width and depth. Instrument separation is better in the sense that there is more air around each instrument, the airiness presentation reminded me of my HD800 and I took it off just to make sure I didn't grab the wrong headphone by accident!
Something else I did not expect was when I first put on the HD6XX, it sounded like it had less bass. But I realized it's due to the much darker background on the HD6XX which puts more emphasis on dynamics and resolution. While the dynamics on the HD600 is flatter making everything sound louder and closer together. With the HD600, you're sitting in the front row, while the HD6XX you're sitting in the sweet spot.
The bass on the HD6XX is obviously smoother but still has better definition and texture. The high notes were a bit peaky when I first got the headphone, but after some burn in they now sound smooth yet full of timbre that makes instruments come alive. Voices are great, the black background really brings out even more texture in the voices (especially female voices on a good tube amp).
Comfort wise, I find the HD600 better, the pads are softer and moulds perfectly to my skull. But that's probably because it's been moulding around my skull for the past 3 years :) Build wise, I do like the gloss finish on the HD600 more than the matte finish on the HD6XX, it makes it look a bit cheap TBH. Also the 1/4 adapter is better on the HD600, the one on the HD6XX looks like it might snap off with a bit of force. The cable is a bit thicker and sturdier on the HD6XX.
My partnering gear is a Metrum Octave DAC with Audiophilleo2 PurePower and a fully upgraded Woo Audio WA6SE. The HD6XX seemed to scale even better as compared to my HD600. On my Lampi, the difference was bigger (but I didn't listen to it for long as it doesn't belong to my headphone rig). I also tried running these two headphones side-by-side on more budget conscious rigs - ODAC+O2 and Aune, and in both setups they sounded more similar than different, and... I actually prefer the HD600 on my entry rig but on my high-end rig the HD6XX is the more involving headphone.
I didn't think anything could top my trusty HD600 for an euphonic sound, until I listened to the HD6XX. The HD6XX is a phenomenal headphone, it sounds great on anything but on an equally good setup it will outshine anything! That is the factual karmic truth.
The only thing similar (but not identical) about these two headphones is the overall signature, or in a way, their tonal balance. However the HD6XX is just more refined in every way, I know Sennheiser didn't intend it to be a direct replacement to the HD600, but it sure sounds like one! The most immediate impression when I compared the two headphones is the obviously larger soundstage (or headstage if you will) on the HD6XX, in both width and depth. Instrument separation is better in the sense that there is more air around each instrument, the airiness presentation reminded me of my HD800 and I took it off just to make sure I didn't grab the wrong headphone by accident!
Something else I did not expect was when I first put on the HD6XX, it sounded like it had less bass. But I realized it's due to the much darker background on the HD6XX which puts more emphasis on dynamics and resolution. While the dynamics on the HD600 is flatter making everything sound louder and closer together. With the HD600, you're sitting in the front row, while the HD6XX you're sitting in the sweet spot.
The bass on the HD6XX is obviously smoother but still has better definition and texture. The high notes were a bit peaky when I first got the headphone, but after some burn in they now sound smooth yet full of timbre that makes instruments come alive. Voices are great, the black background really brings out even more texture in the voices (especially female voices on a good tube amp).
Comfort wise, I find the HD600 better, the pads are softer and moulds perfectly to my skull. But that's probably because it's been moulding around my skull for the past 3 years :) Build wise, I do like the gloss finish on the HD600 more than the matte finish on the HD6XX, it makes it look a bit cheap TBH. Also the 1/4 adapter is better on the HD600, the one on the HD6XX looks like it might snap off with a bit of force. The cable is a bit thicker and sturdier on the HD6XX.
My partnering gear is a Metrum Octave DAC with Audiophilleo2 PurePower and a fully upgraded Woo Audio WA6SE. The HD6XX seemed to scale even better as compared to my HD600. On my Lampi, the difference was bigger (but I didn't listen to it for long as it doesn't belong to my headphone rig). I also tried running these two headphones side-by-side on more budget conscious rigs - ODAC+O2 and Aune, and in both setups they sounded more similar than different, and... I actually prefer the HD600 on my entry rig but on my high-end rig the HD6XX is the more involving headphone.
I didn't think anything could top my trusty HD600 for an euphonic sound, until I listened to the HD6XX. The HD6XX is a phenomenal headphone, it sounds great on anything but on an equally good setup it will outshine anything! That is the factual karmic truth.