Comparing HD800 once modified and kameleonized to HD600 or HD650 filtered or kameleonized, which are your findings about?
Where exactly are you feeling an higher listening experience through HD800?
Have been comparing Kameleonized HD650 to HD800.
Note that the HD800 on a Kameleon (thank God) sounds NOTHING alike the stock HD800.
The decision is a bit 'split' in two.
Otherwise (again via the Kameleon) they sound tonally very close.
The HD650 has smoother and (much) better extended treble and is clearer sounding (no dip at 3kHz).
Measurement wise this is also visible in the plots because the HD800 shows a dip and more wobbly treble reponse (more so due to the filter) and doesn't extend as far (heavier membrane)
The HD800 is slightly 'cleaner' and (because of the 3kHz dip) still clear but less 'edgy' in presentation.
Because the amount of treble is greatly reduced by the filter the 'extremely wide and highly detailed stereo image' is now just slightly wider and slightly less 'extended' than the HD650.
The super wide and hyperdetailed sound of the HD800 is clearly a result of the treble 'plateau' and the 3kHz 'dip'.
Bass wise the HD800 is slightly cleaner and maybe somewhat better defined.
Both have equally great bass extension with impressive but not exaggerated movie-theater type rumbles on some recordings.
Tonally the HD650 is more correct and with more clartity.
Stereo image wise the HD800 is still stlightly better but NOT by much.
The HD800 is slightly better in separating individual sound sources and sounds 'cleaner' and less edgy (3kHz dip).
So on very well recorded music I would be equally happy with both headphones where the HD650 feels slightly more 'real/accurate' and the HD800 slightly more 'pleasant'.
Another thing that only stands out with very well made recordings is that the HD800 is more 'realistic' and you can 'separate' or 'pinpoint' individual instruments better.
Moer realism.
On lesser recordings with 'sharper' recordings the HD800 is more pleasant (3kHz dip and earlier roll-off)
Then there is comfort.
The cable of the HD650 is MUCH MUCH better. More supply, not microphonic, lighter in weight, easier to roll to a small 'package'.
HD800 feels spacier around the ears but also may not seal as as good on less 'round' faces.
For me seal is no problem.
Your ears don't feel as 'closed-in' as with HD650.
Pads of the HD800 feel more pleasant to the skin than my (old and comfy) HD650 pads.
New HD650 pads do not feel as comfy to me as the older ones.
Clamping force of the HD800 is slightly lower and thus slides when moving your head, the HD650 stays in place.
The headband of the HD800 is not as comfortable as the HD650 to ME (may be very different to someone else).
So..... torn... in that if I would have to choose and could keep only one I may end up with the HD800 because (again on the Kameleon) is slightly more 'pleasant' sounding and cleaner as well as spacier.
When I would not have bought the HD800 second hand for a decent price and would have gotten one on loan for a while or would have needed to pay a retail price I would have been happier with the HD650.
I would say the improvement in sound is very marginal compared to the relative leap in price.
Needles to say that in stock form the HD650 with new pads is the more 'honest' one and less fatiguing.
The HD800 is 'lean/bass light and shrill' as well as overly 'detailed and spacious' relatively.
The Kameleon transforms the HD800 more than the HD650.
Both improve but in different ways.
HD650 is cleaner/clearer/faster and unexpectedly impressive in bass performance on the Kameleon.
HD800 is much 'fuller' sounding and much warmer. All the exagerated aspects the HD800 is known/renowned/hated for are reduced to HD650 level but just maybe a tad better still.