- The reviewed IEM is a sponsored unit by KeepHiFi. Regardless, all opinions are original ideas, there is zero influence from any 3rd party or external opinions.
- No EQ or filter presets were used during the entire review period.
- Sound evaluation are kept neutral and does not include 3rd party accessories (ie; eartips, cable, reversible/irreversible mods)
Rating
| Pros: | Cons: |
| Comfy ergonomics.Efficient to drive.Warm, engaging bass with exciting treble tuning to match.Strong vocal presence in the midrange.Good detail retrieval and dynamic range. | Shouty upper-mid and peaky treble which may introduce ear fatigue.Sibilant. Unnatural timbre, hollow, and thin midrange.Trebles are metallic and harsh sounding. Lacking driver responsiveness, resulting to polite, soft bass slam and poor sub-bass. |
Introduction
CCZ was once, one of the name commonly seen in the affordable IEM segment back then throwing fists and punches to reign the top spot which brand could produce the most IEM in a weekly basis against other companies such as KZ, CCA and so on. Although they are less heard now , CCZ still come out with some brand new IEMs and with that I would like to introduce what we have in review for this time.
With me in this review is the brand new CCZ DC02 Solo, a single dynamic-driver IEM featuring a 10mm dynamic-driver with a combined PU and PET diaphragm design, priced at just a shy below US$20. Plenty thanks and appreciation to KeepHiFi for their willingness to send a unit over for a trade with an honest review. Thus, without any due further let us get on with today’s review of the CCZ DC02 Solo!
Unboxing Experience
The unboxing experience for the Solo is nothing to be amazed of to begin with, which if you’re well acquainted with some of the lowest-end IEMs in the market such as KZ, QKZ, TRN and so forth. Thus, this one should be no surprise for you either.
Regardless, the Solo came in a small sized box with a 3D rendering of the IEM itself on the front cover alongside some of the usual marketing features. Meanwhile, at the back you’ll find the full specifications list for the IEM. Sliding the outer layer cardboard away unveils the IEM itself resting on a cardboard cutouts. As we further move on deeper, you’ll find the accessories for the IEM such as a set of generic silicone eartips, a standard 3.5mm to a 2-pin connector cable which I will dive deeper into as we get into the review and a bunch of paperwork as well. Pretty basic, bare bones unboxing experience but suffice in anyway for a basic IEM.
Specifications
Nozzle Diameter: 5mm
Driver: 10mm dynamic driver with PU + PET diaphragm
Impedance: 20 Ohms ± 2 Ohms
Sensitivity: 103dB±2dB
Frequency Response: 20-20kHz
Cable: 1.2m, 4 cores OFC copper cable with 2-pin (0.78mm) to 3.5mm
Build and Comfort
Speaking of build quality for the CCZ DC02 Solo, the majority of the build material is primarily resin, while the face plate is made out of metal giving it a substantial amount of weight onto these earpieces. The design features a conchae support which has this kind of integrated hook that slides into your conchae giving support to distribute the weight of the IEM evenly. To add onto that as well, there’s a rubber cover on the conchae support to provide a touch more comfort. As far as I could confirm, the overall build was alright, there is nothing that stands out but one should not expect that the Solo could take a beating or constant drop due to the shell structure is fairly thin and primarily attached with adhesives.
In terms of comfort, I could wear the Solo for quite a long time without any fatigue due to the good ergonomics and the effective conchae support. However, although I could not confirm that this occurs to all units for this IEM, the batch that was sent to me suffered from driver flex which produces this crinkling sound whenever I try to insert this IEM into my ear canal despite I did my best to swap with different eartips. This might due to poor venting design of the IEM. Regardless, the IEM did not suffer from any permanent damage since driver flex are known to deform the diaphragm of the driver.
Cable
Cable that comes stock with the CCZ DC02 Solo was a 4 core OFC cable with a 3.5mm termination to a pair of 2-pin (0.78mm) QDC connectors on the other end. It comes with two choices to choose, whether to have it with or without the inline microphone cable. I will go though this cable fairly simple and quick since there is not much to talk about it.
The build quality on this cable is pretty substandard reminds me of those cables that comes with those US$5 KZ cables back then. It’s thin, prone to tangle without proper storage which can be annoying. Protecting each core of the cable is a thin layer of PVC, which feels quite tacky and flexible. Apart from that, the cable does its job really, surprisingly it does not emit any microphonic when rubbing against my clothes or anything while wearing the IEM.
Test Equipment
- Local Hi-Res files > Astell&Kern SE100 M.Chat (Linear Phase Fast Roll-off Filter)
- Tidal (Master) + Local Hi-Res files via UAPP > Sony Xperia 1 V + DSEE Ultimate (ON), Dolby Atmos (OFF)
- Tidal (Master) + Local Hi-Res files via UAPP > Sony Xperia 1 V > Venture Electronics Odo (3.5mm)
- Tidal (Master) + Local Hi-Res files via UAPP > Sony Xperia 1 V > Kiwi Ears Allegro Mini (3.5mm)
- Tidal (Master) + Local Hi-Res files via UAPP > Sony Xperia 1 V > Muse Hifi M3 II (3.5mm)
Power Requirements
When tested with various equipment within my possession including my usual reference. I could confirm that the CCZ DC02 Solo could run from pretty much anything I plugged into, whether it be through my Sony Xperia 1 V, Kiwi Ears Allegro Mini or through the Venture Electronics Odo. The combination of high sensitivity at 103dB and low impedance at just 20 Ohms, allows this IEM to shine efficiently without the need of powerful source. For instance, driving the Solo using my Sony Xperia 1 V through the 3.5mm requires me to crank up the volume rocker up to 8/30 to achieve my comfortable listening level. Similarly when plugged into my reference DAP, which was the A&K SE100 I could not hear any difference in terms of efficiency of the drivers responsiveness when plugged into a much powerful source.
Initial Impression
The CCZ DC02 Solo has undergone burn-in phase for at least 48 hours prior to sound evaluation. Throughout the analysis, I paired up the Solo with a neutral source, the A&K SE100 on Linear Phase Fast Roll-off Filter chosen given that it’s the most natural sounding filter compared to default. Eartips used are the stock generic black eartips provided in the package. Bonus test tracks used can be found down at the end of this review.
The CCZ DC02 Solo reminds me of those old V-shape IEMs back in the day when I was just starting to indulge into this enthusiasm back in 2018. Overall sound of this IEM was more towards this warm, boomy kind of sound signature due to the low-end with an aggressive high frequencies which was evident through the measurements. As one can see the peaks and dips starting from the ear gain region at an approximate 2.5kHz all the way up to 20khz.
Subsequently to that, midrange suffered quite the most though that is a common scene for IEMs with these kinds of tuning. I spent a good amount of time with the Solo and trying to understand the midrange quality. Although it did not blew me out of the park, I could least appreciate it could present a strong vocal presence due to the 1kHz peak despite the rest of the midrange was still I would say its recessed. The Solo isn’t gonna be the smoothest, pleasurable experience one could ever hear coming at this price point but I can still see it as a versatile pair, suitable for wide genres of music. Regardless of what it is, now we can dive deeper into the sound evaluation.
Low Frequency (Bass)
Being a sub US$20 in-ear monitor, I didn’t expect the Solo to deliver me outstanding bass quality due to possible limitations such as driver capability, quality and the material itself which fundamental part how efficient a dynamic-driver could perform. Nevertheless, the low frequencies for the CCZ DC02 Solo could be described as warm in terms of tonal balance, boomy and ironically polite considering the amount of bass shown in the graph earlier.
There are not a lot of details could be spoken in regards to sub-bass rumble effects, subwoofer effects and etc within the sub-bass region. For instance, I put on my usual bass track Hollow (16 Bit Remix) – Björk to test out the bass driver capability to reproduce deep sub-bass and the Solo was unable to do so. Entering 30 seconds into the track, I could hear that the driver were struggle to render such deep sub-bass and only subtle, almost non-existent rumbles I could felt which might be an indication to sub-par magnets being used for the driver. Hence, despite the marketing flair one shouldn’t expect that the Solo could provide head shaking, invigorating experience sub-bass rumbles.
Moving towards the mid and upper-bass of this IEM, it can be said that the Solo presented its bass slam in a polite manner and surprisingly fairly clean and does not interfere with a lot of the other frequencies. There are not a lot of bass slam to report, as it is anticipated with moderate attack and speed, with each punch resembles more to a pillow-like, lacking in weight, soft “thud” rather than a strong, hard-hitting slam. There are also not much depth within the bass slams as it dissipates very rapidly after each slam, which tells me a sign that this IEM has a rather fast bass decay. Overall, the bass performance for the Solo was decent, it could provide the listener a good introduction about bass heavy sort of tuning but again, I wouldn’t call it a brilliant performer either due to the lacking sub-bass quality and mid-bass punch.
Middle Frequency (Mid)
In short, the CCZ DC02 Solo presents its midrange in a slight warm in tonal balance due to the emphasis in the lower-mid, yet surprisingly still quite clean with an aggressive upper-mid which might put off some folks including myself. But to be frank, I am not impressed with the quality of midrange from this IEM.
While I could appreciate the vocal forwardness and presence that this IEM could present, especially in ballad songs and etc. It does emit an unnatural timbre that was obvious when we’re talking about accuracy to reproduce sound of various stringed instruments such as guitar, violins and so on. For example, in tracks such as Crystal Ann – Annihilator, guitar strums sounded quite thin, cold and artificial due to the tuning. While in other songs in my library, certain elements of instruments such as toms in drums are hollow and veiled which can be a bit difficult to hear without the need to crank the volume louder.
Moreover, speaking of vocals on the Solo although I did mention about the strong vocal presence that this IEM could deliver which I certainly appreciate. However, the rest of the upper-mid are severely nasally sounding and lhollow in terms of note weight, which makes my usual go-to artist for vocals such as Uru and Laufey sounded rather cold, lifeless and shouty. There was not much texture and small nuances to report which is expected due to limited driver capabilities.
High Frequency (Treble)
Reaching higher into the high frequencies, the Solo tonal balance in the treble skews more towards a brighter leaning treble. Other than that, this IEM has a sparkly treble, decent air with good energy and presence which made the overall treble sounded engaging, exciting and lively. However that said, it can be quite tinny and harsh with hi-hats, crashes or anything that involves elements in the high frequencies. Such as, the sound of violins playing high notes in Artemis – Lindsey Stirling reproduced from the Solo had a hard metallic edge to it which sounded quite unpleasant.
To add onto that, based on my listening there was obvious sibilant that can be heard with the pronunciation of “s” and “t” along with the tail of cymbals and hi-hats. From my personal experience using this IEM, I have a moderate tolerance to high frequencies and the Solo does trigger my sensitivity not because the IEM was overly bright, but more so due to the peaky, uncontrolled treble which also translate to ear fatigue after using it for a short period of time. Perhaps, if CCZ could work on their tuning to reduce the peakiness through dampening or by utilizing filters then there’s better chance this IEM would be much more enjoyable.
Technicality
In terms of technicality, starting with soundstaging and spatial imaging (localization). It can be said that the CCZ DC02 Solo have a rather small soundstage, thus projecting the sound quite intimate and close to the listener. That said, there is still decent depth and width within the soundstaging, while most tracks will sound typically normal with the Solo. Something like orchestral, binaural recording or classical might not be great or nearly as immersive as one would prefer. Imaging on this IEM was pretty poor especially when rendering complex movements accurately, but if doesn’t have any problems rendering simple, macro details panning left to right on a flat 2D plane which is pretty normal within this price segment.
Furthermore, detail retrieval on this IEM is honestly quite good, although it was not outstanding by any means I could still hear those micro details and small nuances by a noticeable amount which can be further enhanced by swapping eartips. That being said, resolution or clarity rendering produced from the Solo was fairly poor, there is not much texture, complex nuances to report when all of the details are blurry and lacking in definition. Advancing to the next aspect, that is separation and layering. In my opinion, the separation on this IEM was acceptable it can separate limited amount of elements in a track before it gets severely congested. Meanwhile, layering was poor as I could not sense any space between the elements as if they’re melded together. For instant in tracks like The Feel – RC & The Grits, a fusion jazz genre track which combines multiple instruments. Lastly, wrapping it off with the dynamic range test for the CCZ DC02 Solo is rated at average. Utilizing the Ultimate Headphone Test – ABYSS Headphone dynamic range test as a reference. In which explained in short, a sample sound of a drum and a bell are played simultaneously as much as 7 counts, but only the sound of the bells will become quieter. Hence, from a scale of 7 counts, Solo was able to produce an audible 5 out of 7 counts.
Eartip Combination(s)
- EPro EP00
Recommended pairing with the CCZ DC02 Solo though it costs half of the IEM. My reasoning is it allows the soundstage to stretch a bit more wider and spacious. Low frequencies became a bit more rounded, weighty delivering bass slam compared to stock eartips. Midrange and treble became less edgy and helps a bit with the sibilant issue, thus resulting to a much smoother, tolerable level. Upper-mid remains slightly shouty and overall midrange still sounded thin, hollow but at least it doesn’t sound aggressive as per with stock eartips.
Purchasing Links and Where to Get?
- KeepHiFi Official Store
Conclusion
As I am crafting my thoughts to conclude the review for this IEM, I cannot help to think where does this IEM stand in the sea of hundreds of US$20 IEMs. All I’m saying is that great starter IEMs are now available, achievable in the market thanks to daring companies that strive to achieve the impossible bringing in excellent price to performance ratio products from brands such as the Tangzu, 7hz, Moondrop and Truthear. Thus, making brands like CCZ became less and less relevant despite their best effort to provide IEMs that would only please a certain genre of demography and newcomers with little knowledge and background research in regards to this hobby.
Nevertheless, from my point of view the CCZ DC02 Solo would probably please those who are searching for bassy, warm kind of tuning without sacrificing vocal presence considering that this IEM has a fairly strong upper-mid gain, though it does let other elements in the mids to drown and to be unnatural sounding due to the strong influence of V-shape tuning. Thus, that should to it for me for this review, hope I’ll see you in the next one.
Additional Test Tracks
Money For Nothing (Explicit) – Dire Straits 44.1kHz
A Poem Titled You – TAEYEON 44.1kHz
Anesthetize (Live) – Porcupine Tree DSD256
Vermilion – Slipknot 44.1kHz
Hunter – Björk 44.1kHz
La vaguelette (Original Game Soundtrack) – HOYO-MiX 44.1kHz
Rhythm – Jamey Haddad, Lenny White; Mark Sherman 44.1kHz
Kimigatame (When Suara Meets DSD 11.2Mhz) – Suara DSD11.2MHz
Automatic – Hikaru Utada 44.1kHz
In My Room – Hikaru Utada 44.1kHz
Colors (Live in Studio) – Black Pumas 192kHz
Timbres – Yosi Horikawa 44.1kHz
Misguided Ghosts – Paramore 44.1kHz
