AZLA Zwei Review: Private and mellow

AZLA Zwei Review: Private and mellow

Anyone aware of the brand called AZLA? Perhaps you may have heard about the Sedna Earfit eartips. Previously in About Audio, we have covered two AZLA IEMs as a review – Horizon and Orta. Fortunately enough, I have joined one of the Japanese show in the past where AZLA first made their debut to the portable audio market. The visitors’ impression turned out to be very positive, thus I have purchased their first model, 01R, and started to keep myself updated with products from AZLA.


This Korean brand that is rather new to the scene has been growing an explosive amount of interest from the Asian market and especially from Japan. AZLA recently announced two new IEMs that will be joining the family, this time with a rather affordable line-up. One is named Zwei which is a mid-low priced IEM, and the other is named Azel – a lowest-priced entry model released from AZLA which we will be covering today. Let us now see how they have done their sounds at a budget level.




Zwei includes quite a big set of accessories in a small package. Other than the earpieces, the packaging includes a stock 2.5mm cable, 2.5mm to 3.5mm conversion cable, 6 sets of Sedna Earfit Light eartips, a hard case, a cable tie, and some paperwork. The hard case is big in size and capable of storing extra accessories or another earphone. Note that there exists a 3.5mm packaging version, where the stock cable is terminated with a 3.5mm plug and does not include the 2.5mm to 3.5mm adapter. Zwei is available in two color variations which are Emerald Green and Wine Red.



Earpieces / Cable

The shape of the housing is identical to the one used for Orta with a smoothly polished interior, making it possible to be worn either over-ear or straight-down. AZLA’s symbolical tuning method, Infinity Sound Technology, has been applied for a majority of their products including Zwei. This particular technology is AZLA’s unique ventilation system where a large venting port is applied to the driver within an enclosed cavity. This is to mimic a certain structure that is often applied for speakers as well as to achieve both isolation and an open-field sound.


For the drivers, Zwei uses 2 Knowles balanced armatures per side (1 full-range, 1 woofer) with an inner chamber called the Acoustic Sound Chamber +. This is to isolate the drivers from housing and prevent unnecessary resonance. Since the beginning, AZLA has been persistent in installing the drivers coaxial and the same goes for Zwei. The earpieces are detachable via MMCX connectors and with the diameter of the nozzles being somewhere between T400~T500, making it compatible with most aftermarket eartips.


The stock 2.5mm cable is made of 4-core high-purity OFC wires with each core consisting of 30 strands. All connectors and Y-split are covered with a metal casing and well built. The included 2.5mm to 3.5mm adapter uses the same wires and components like the 2.5mm cable with strain reliefs installed on both plugs. Microphonics would barely happen as the wires are smooth and light.



Sound impressions: Lows

Zwei draws a smooth, reference sound signature with enhanced bass. Lows produce a thick, superdense sound ray with the quantity of a slightly v-shaped IEM, carrying a large punch to the lows but not to the point of getting rough. The ultra-low extension is remarkable considering its 2BA driver configuration – or I could even omit to consider the driver counts since the bass is already great enough, just as it is. I was not able to find any particular shortcomings in quantity and details. 


Its nature is quite interesting for several reasons. First, while the bass quantity is plentiful with gentle splashes of reverbs, Zwei strictly keeps these two elements highly under control, only allowing them to mingle on the lower side of the headroom. Second, the texture. lows do a fine job displaying the bass texture but in no gruff manner. Last is to do with its density. I have experienced that many 1~3BA IEMs, in general, are much possible to create enough bass quantity but often get loosen and struggle to keep a tight density. It is difficult, though not impossible as Zwei is one of them that would keep the bass packed and dense enough. Overall, the low-range flows at a very steady pace without causing drastic turbulence.



Sound impressions: Mids

Like the preceding, its ventilation system and the driver cavity were structured to mimic the internals of a speaker. After all, AZLA’s effort towards this particular tuning shines charm as mids thoroughly fill the headroom with a clean, subtle resonance. This gives a good size to the vocals just as other IEMs with full-bodied vocals, yet the vocals from Zwei would interpret a headroom similar to a speaker.


Thus, mids would continue an extensive harmony with the lows but with sharp distinction and would not end up in one big lump. Zwei shows a very organic and natural tone that possesses a dark, vivid color that strengthens its speaker-like characteristics. Though the brightness and air slightly go up once the vocal enters the upper mids, helping the vocals to gain some shine rather than sounding deafened. This upper mids highlight takes place gradually and mildly, so no spikes or sibilances would occur. Instead, I hear a mild metallicity near the sibilance area, though this serves to add crunch to the vocals and would not deteriorate the tonality.



Sound impressions: Highs

With a well-groomed manner, highs show a fast and prominent response. The strikes are clear, natural to its tone, and show high concentration both in moisture and crispiness. It makes its presence a small step back from the mids with lesser quantity, though the brightness here is on the shinier side while low and mids are darker. In other words, the contrast maximizes and would let the treble to preserve its sharpness even with lesser quantity. Since that, the high notes would achieve both the clarity and fatigue-free environment.


The staging is similar to a feeling where a set of decently-sized speakers are placed in a closed room, creating an up-close and personal environment. Unlike its cute and compact cavity, the staging is on the larger side and achieves wide side space and depth. The background is quite clean with a pitch-black theme, helping the bass to expand its size and seriousness. One of the largest reasons why I appreciate AZLA IEMs is that they aim for high imaging accuracy – so each instrument is positioned with the clear phase and focus point, which is also evident from Zwei.




-Campfire Audio IO-

Compared to IO, Zwei has a dimmer coloration, expressing a more neutral and condensed tone. Lows have a slightly fuller body plus a higher density while IO has a softer and fluffy feeling to it. Zwei’s mids are warmer, slightly darker, and keeps the vocals extensively connected with the lows as IO draws a clear line between mids and lows. There is more air on IO throughout the mid-range, yet Zwei also gives off a fair amount of silvery crisp on the upper mids, compensating to its warm signature. In the case of highs, IO keeps its treble presentation on the higher end with a softer breeze while Zwei’s treble is positioned relatively lower but with more firmness and density.


-OBravo Cupid-

The nature of these two IEMs is a lot different. Cupid desires a vivid, colorful sound signature tuned for extra excitement while Zwei has a more neutral timbre with a natural and smooth presentation. The bass quantity is not so different in quantity, yet Cupid achieves slightly better ultra-low extension while Zwei is a bit more fuller in the body. Mids also have more meat on Zwei with a more condensed positioning, being stacked right on top of the lows. In the case of Cupid, the vocal thickness is a bit thinner with much more air and vibrancy going on, plus the stronger coloration but still retains a fair amount of neutrality. Vocals sound sweeter and tastier on Cupid, yet Zwei brings out more thickness and stableness compared to Cupid. The highs and stage sizes are similar, though the difference in staging is that Zwei gives more of a private room feeling while Cupid keeps the roof of the room open. 


-AZLA Horizon-

These two IEMs are similar once looking at the big picture but many differences could be found once we pay attention to the small details. Horizon is a bit flatter (about 15%) compared to Zwei, presenting lesser bass quantity and thickness. The ultra-low extension is mildly better on Zwei, but not significantly different. For the mids, Horizon is linear, retains more air, and highly neutral in both moistness and temperature while Zwei sounds a bit warmer and moist. Horizon shows its superiority in terms of revealing the details and in transparency, yet Zwei has its own advantage by carrying more weight and thickness. The staging style is quite different, perhaps the biggest difference between these two, where Zwei keeps a dark, speaker style room (as said) while Horizon creates a mildly bright and cool, open-field room.




AZLA has been keen on incorporating new, challenging technologies and their results have been turning out to be nothing but success. Zwei is an all-rounder IEM that focuses on a smooth listening environment accompanied by a proper tonal balance. Thus far, this is also the one with the strongest speaker-like sense which has been unique to AZLA products since the beginning. Zwei would be a safe but powerful choice for achieving a sweet, super-smooth sound with an in-private speaker experience. 




AZLA – Horizon     AZLA – Orta     AZLA – Azel     




Thanks to AZLA for providing Zwei in exchange for an honest impression/feedback.

I am not affiliated to AZLA and none of my words were modded or asked to be changed.

Smooth and warm reference tuning
Accurate imaging with its unique room-feel staging
Quality accessories and eartips
Fatigue-free signature
Can be worn both over-ear and straight-down
Nozzles may be a bit long for some
Not meant for those who love bright sounding signatures