i have both of these and they are different for sure. also the jh combo i have is freq phase as well.
bass JH power-full fast but detail is given to the pp6. this observation is with bass boost off, if on the bass for the jh is vastly more power full.
mids about the same both being very detailed, but to me the pp6 has a overall better music presentation.
treble again about the same but pp6 having more musicality.
what i mean other than the bass, the pp6 is more overall detailed all the music as a hole , where jh gives highlights as if you were in the studio with the band but there seems to be a symbol crash or guitar riff that just sounds like it is missing something as compared to the pp6. one more thought the pp6 can only be used with the dac/amp combo as the adapter was not available when i received them.
if driven with an external amp/dac of good quality the jh 16 is more closer to the pp6, i know this may not seem right as the jh3a and jh16 come packaged but it is what i hear. another comparison can be made with the the tg 334 this is more closer to the jh than the pp6, as the tg334 is more of a studio master sound than a audiophile listening device .
just my observations and please excuse the grammar and lack of terms.
this is doing an A/B test same song same track both using coax input flac files .