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Sony XBA-Z5 Review (IEM)


Active Member
Forum Donor
Feb 21, 2019
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A friend drop-shipped Sony XBA-Z5 to me for measurement. I took this opportunity to write a short review of the Sony XBA-Z5.
MSRP: $631

Launched in 2014, Sony categorized the Sony XBA-Z5 as Sony’s ‘High-Resolution’ audio product. One thing I always ask for this kind of advertisement is, how do they justify the ‘High-Resolution Audio’ label for Headphones and In-Ear Monitors? Is there any measurement to support that claim? I guess the proof of the pudding is only in the listening test.




Shell size is a bit large, might not fit smaller ears very well.


To provide objective proof and measurement results to support the ‘High-Resolution Audio’ claim.
To improve the overall perceived detail and clarity.

The following is my guideline for the sound & engineering quality rating criteria that will be used in this review:

Sound Quality​

Sony XBA-Z5 measured frequency response compared to Earfonia IEM Target Curve (EITC-2021), normalized at the midrange dip:


*More info about EITC-2021 here.

The following is frequency response analysis and rating based on the 4 observation points of EITC-2021:


Overall Sound Signature:​

Moderately warm and bassy. Fat and laid-back midrange with silky smooth treble.

From the frequency response graph, we can observe the followings:
  • Sony XBA-Z5 frequency response is within ±6 dB from my EITC-2021 observations points.
  • Sony XBA-Z5 frequency response around the bass and midrange area is within ±6 dB from the Harman Target IE 2019.
  • Around +3dB bass to lower-mid emphasis.
  • Around -7dB upper-mid recession.

Warm, bassy, and laid back are the few words that I think are appropriate to describe the XBA-Z5 sound signature. It has pleasant and polite characters in the sound quality. Quite pleasing for a long session of listening without causing ear fatigue.

The sub-bass extension is good. Sub-bass to mid-bass balance tilted up towards the mid-bass area. To me, there is too much emphasis around the Mid-bass to the lower-midrange area that makes the midrange sounds a bit bloated to my ears. The mid-bass emphasis makes the bass sounds a bit boomy, lacking texture and tightness. Bass punch and attack are a bit too weak for my taste. Midrange balance has too much emphasis on the lower midrange and the upper midrange response is too soft. Midrange sounds laid back, lacking presence and clarity. Treble is nice, sounds silky smooth without any sign of harshness, but a bit soft, lacking a bit of treble energy, sharpness, and perceived upper treble extension. The treble doesn’t sound dull, but at the same time lacks transparency, airiness, and the perceived ‘High-Resolution’ treble extension.

The sound signature of the Sony XBA-Z5 is not exactly my cup of tea, and as we can see from the frequency response it deviates a bit far from my target curve. So XBA-Z5 sound signature doesn’t sound balanced or close to neutral to my ears. I cannot use XBA-Z5 to mix my recordings. It is moderately colored with emphasis on the bass to lower midrange area and recessed upper mid. Having said that, I think XBA-Z5 doesn’t sound bad, and it can be quite pleasing and enjoyable with certain recordings like modern pop, especially the brighter ones. There are many positive reviews of the Sony XBA-Z5 that indicate that it has a likable sound signature. Not natural but likable. It is moderately colored with (I think) the type of pleasing coloration that our brain can easily adapt. No offensive peaks across the audio band. The tonality coloration can be perceived as a nice coloration for those who prefer a warm sound signature. Overall, it is good enough for casual listening but not for critical listening and Pro Audio applications.

Perceived detail, resolution, and clarity are ok but not great. Instrument separation is sufficient but not as good as what I would like to hear. Spaciousness and airiness are lacking especially for orchestral works. Transient and attack are a bit slow and blunt. For an IEM with a ‘High-Resolution’ label at this price category, I expect a lot more. I would give the liveliness score 6/10, good enough but not great.

Since I’ve mentioned that XBA-Z5 sound quality is not my cup of tea, I don’t see the reason to do comparisons with my other favorite IEMs (obviously, they sound better).

Engineering Quality​


Disclaimer: The measurement results of the engineering quality measurement in this review represent only the pair of IEMs that was measured for this review. It doesn’t represent the overall quality control of the factory.

Left-Right Mismatch​

Observation range: 20Hz – 7kHz
The unit has an overall under ±2dB matching from 20Hz-7kHz, with a 1.9dB maximum mismatch at around 6.7kHz.


Harmonic Distortion​

Observation range: 55Hz – 7.1kHz

Sony XBA-Z5 performs well in distortion measurement. Overall THD level is quite low. Only at a high volume level, the distortion peak is a bit high, but in my opinion, it is not a concern. Left and Right channels show similar THD profiles. There is no abnormal distortion peak across the measurement range. Please take note that distortion measurement is not part of sound quality evaluation. It is only used to observe the engineering quality of the IEM.
Distortion measurement at 94 dB SPL at 500Hz:



Distortion measurement at 104 dB SPL at 500Hz:



Harmonic distortion analysis:

Electrical Impedance​

Observation range: 20Hz – 20kHz
The impedance curve is relatively flat from 20Hz to 1kHz, followed by a rise and a steep downslope around 3-4kHz. Overall impedance linearity is still ok for a hybrid IEM.



At 98.1 dBA SPL at 100mV @ 1kHz (measured) Sony XBA-Z5’s sensitivity is around the average, slightly higher than the Etymotic ER2XR which can be considered a bit low. Most portable devices would be able to drive Sony XBA-Z5 sufficiently, but a good quality DAC+Amp will improve the perceived dynamic, liveliness, and overall sound quality.

Fit, Comfort, & Build Quality​

Subjectively the Sony XBA-Z5 is quite comfortable for me. No issue with comfort. I would give a comfort rating of 8/10 for XBA-Z5. But please take note that it is not a small IEM so comfort level could be greatly varying between individuals. I’m not a fan of cable with memory wire but it seems necessary for the XBA-Z5 design. The wearing style of XBA-Z5 makes the memory wire is recommended on the cable end that connected to the driver. This can be an aspect for consideration for those who prefer not to have memory wire in the cable.


The 2x 3.5mm balanced cable that is included in the box is suitable only for Sony’s headphone amplifier with 2x 3.5mm balanced output.


The build quality of the Sony XBA-Z5 is generally pretty good. All plastic The full-Magnesium housing feels strong and sturdy. I don’t see any issue with the build quality.


Although Sony XBA-Z5 is good enough for casual listening (not for critical listening and Pro Audio applications), at this price point I cannot recommend the Sony XBA-Z5.

More information about my IEM Measurement Setup & Methodology:
Earfonia IEM Measurement Setup & Methodology

Advertised Technical Specifications:​

Drivers: Hybrid 3-way – 16mm dynamic + 2 Balanced Armature
Frequency Response: 3-40,000Hz
Sensitivity: 107dB/mW
Socket: MMCX
Last edited:


Active Member
Jun 29, 2020
Nice detailed review of an... interesting IEM. Surprised there's no issues with comfort, the design seems like it would be annoying sticking out like that.


Active Member
Forum Donor
Feb 21, 2019
Thank you! Yea, I used them for a rather long listening, the comfort is surprisingly quite ok with me. And after few days my brain kind of accepting the warm sound signature of it. But I only like it for modern pop recordings, not for orchestral work.

I edit the cons, I think the 'unique' 2x 3.5mm balanced cable shouldn't be considered a cons point. It is just their way to fit their own system.

And in case someone asking how it compares to Sony MH755, here is the comparison:
Sony XBA-Z5 - Sony MH755 - EITC-2021 - HTpng.png
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