[karlsonklam]

curious about why several of my IEM sound so anemic in the low end with the Walnut - even with its largest sounding EQ setting "JAZZ" and why "POP" is muted so much - - look at the curves below.

Line Out with "JAZZ" looks very good

Are the Zishan Z1 and Z2 EQ curves identical? How about presets with the Zishan T1 ?

 

[castleofargh]

first, you're talking about some pretty obscure cheapo devices like everybody knows them and how they work. based on the number of answers, that it did not go well.
EQ presets are typically something that a given manufacturer decides for himself. no real point trying to guess why they picked something. maybe the pop setting assumes that pop music will have close to full scale signal all the time so they went down a little to limit risks of clipping? or maybe they just ran out of EQ ideas so they changed the gain to give the user a feeling that the other settings had a lot of impact and sounded nice in comparison? I'm making up possibilities as I have no clue.

the unloaded responses do seem to show some low end roll off even in the best case scenario. but there could be other reasons for low end roll off pilling up over this. like a high impedance output+your IEM having lower impedance in the subs than in the rest of the audible range. or maybe some protection capacitors, that would low pass the signal. in that case, the lower the IEM's impedance, the bigger the low pass. I'm not saying this is the case here as I don't know that DAC/amp. but if you feel like what you're hearing is even worst than what you measure unloaded, then one of those 2 possibilities could be the answer.

 

[karlsonklam]

Thanks for the insight. FWIW, I'd guess a Y coming out of the headphone jack with headphone on one side and soundcard/RTA on the other would (?) show some loading/highpass effects - but not the interaction of Z-out with the DUT's response. I mainly was curious of why there didn't seem any bass boost with my CCA12 and why in general, "Jazz" setting sounded fuller. I really didn't know which forum to post as may not be noteworthy or appropriate for this one.

 

[karlsonklam]

I forgot to mention that those EQ curves were taken with no load other than the ~10K input of the soundcard. When looking at the line out I had an SHP9500 load on the headphone out and those curves looked approximately identical other than "Jazz" not having the HF droop seen at the headphone out.