KZ ZS10 - MEASUREMENTS AND COMPARISONS: FREQUENCY RESPONSES AND IMPEDANCE
DISCLAIMER: All measurements by a friend of mine - using my iems. He lives only 50 m upstream along our joint gin & tonic pipeline. The following will be a shaken (not stirred) mix of his and my ideas and comments.
1. FREQUENCY RESPONSES
1.1. KZ ZS10
Observation: Strong V-shape. Slight mismatch of L and R channels above 2K.
Interpretation: V-shape explains the recessed mids. Whether the channel mismatch above 2K is a measuring artefact or reflects a manufacturing inconsistency beats me (but is sonically not significant).
1.2. COMPARISON ZS5 v1, ZSR, ZS10:
Observation: All three have a V-shape (or W-shape) with a trough in the midrange at around 700 - 900 K . All three curves climb to peaks in the lower treble 2 - 3 K region. The ZS10 has the most emphasized bass and treble peak of the three and therefore the most pronounced V.
ZS5 v1. and ZS10 have rather similar FR curves whereas the ZSR's curve shows less emphasized lower treble.
Interpretation: The strongly V-shaped FR curve of the ZS10 produced by 5 (!) drivers and the similarity to the ZS5 explains why owners of the other KZ multidrivers and/or audiophiles are not thrilled by the ZS10. The ZSR appears strongest in the mid and upper treble.
2. IMPEDANCE ZS5 v1, ZSR, ZS10
Observation: The impedance profiles of the ZS10 and ZSR are rather similar and contrasting to the ZS5's.
Interpretation: ZS10 is very well behaved for a multi-BA: essentially flat at ~33 ohms (the mfr spec says 32, that's probably right, depending on the phones the rig can be up to 2 or 3 out) to ~3k, then dropping off through the treble. Compared with the ZS5 (crazy low) and even the ZSR this is pretty good.
This means bass vs midrange of the ZS10 will not be expected to change in level with the output impedance of the amplifier used. It might of course change in level or (more likely) quality because of the quality of the amp or DAC, but that's a different issue.
Increased output impedance of the source should tame treble in the ZS10 and ZSR, and slightly boost treble in the ZS5. My friend is generally surprised by the smooth impedance curve; he had expected a bumpier ride from the 4 BA drivers.
3.
CONCLUDING REMARKS
The FR response curves show why people who like vocals will likely prefer the ZSR over the other two models. The curves also confirm my earlier ZS10 impressions posted in this thread. People who liked the ZS5 v1 will probably like the ZS10 for the same reasons. The ZS10 has better detail so that ZS5 fans would likely view them as an improvement. (Apart from its upper treble peak) my friend and I still prefer the ZSR.