I also agree with most all of the above.
I would add excellent headphones have very little phase shift, as their single diaphragm moves nearly/almost as one solid piston through the range of 200Hz to >8kHz.
In that same range, most all speakers have hundreds of degrees of phase shift (time delays), which change with the frequency being reproduced.
A lack of time-domain distortion can also be called a high level of time-coherence. This is not the same as phase coherence.
Time-coherent operation goes a long way to revealing the touch on any instrument, the enunciation and inflection in any voice, intense dynamic contrasts, and clarity of the individual artists, almost regardless of what those headphones might be plugged into.
I use the word 'any' in the last sentence, for you should be able to track those characteristics of the performance through any tone range/any performer. Also, any image, as odd as it may be to hear it inside your head, should be stable in any tone range.
If you encounter a tone range where something isn't right about one of those characteristics, you are in a range where phase shift and possibly other distortions are high.
My first truly involving headphones were Koss ESP-9's. Still have them, now with a dead power supply, but someday...
Best regards,
Roy Johnson
Designer
Green Mountain Audio
I would add excellent headphones have very little phase shift, as their single diaphragm moves nearly/almost as one solid piston through the range of 200Hz to >8kHz.
In that same range, most all speakers have hundreds of degrees of phase shift (time delays), which change with the frequency being reproduced.
A lack of time-domain distortion can also be called a high level of time-coherence. This is not the same as phase coherence.
Time-coherent operation goes a long way to revealing the touch on any instrument, the enunciation and inflection in any voice, intense dynamic contrasts, and clarity of the individual artists, almost regardless of what those headphones might be plugged into.
I use the word 'any' in the last sentence, for you should be able to track those characteristics of the performance through any tone range/any performer. Also, any image, as odd as it may be to hear it inside your head, should be stable in any tone range.
If you encounter a tone range where something isn't right about one of those characteristics, you are in a range where phase shift and possibly other distortions are high.
My first truly involving headphones were Koss ESP-9's. Still have them, now with a dead power supply, but someday...
Best regards,
Roy Johnson
Designer
Green Mountain Audio