AAW W900

A Hybrid Flagship!

PROS: very coherent tuning, smooth resolving signature, excellent soundstage expansion, compact design.

CONS: benefits from a cable upgrade to scale up the sound to its full potential.

The product was provided to me free of charge for the review purpose in exchange for my honest opinion.

Manufacturer website: AAW, available for sale on MusicTeck.


It’s very common today to see IEM flagships packed with an impressive number of BA drivers or an ultra-wide bandwidth single DD. But each one has its challenges, for example, trying to achieve a coherent tuning of multiple drivers or trying to cover the entire frequency range with a single driver. And if you talk about hybrids, the challenge is not only with coherency of the sound tuning but also being able to fit everything inside the shell while accommodating both the array of BA drivers and a dynamic driver which requires a proper venting. Perhaps that’s a reason why 3way (2BA+DD) is still the most popular hybrid design, while anything 5way and greater is not as common. Coincidentally, AAW was among the first to introduce 4BA+DD in their previous W500 flagship.

Now, AAW is back with another flagship hybrid. Due to so many available IEM choices it’s not easy to get audiophiles attention these days, but AAW announcement of 9way hybrid (8BA+DD) did the trick! Even so I received W900 over three months ago, I have been using these IEMs almost daily and have featured them in many of my latest reviews, either as part of a comparison or a pair up with different sources and cables. There is no denial, I still enjoy them very much, and now I would like to share with you in more details why.


W900 arrived in a rather plain white packaging box with Advanced Acoustic Werkes (AAW) logo on top. A more premium storage box was found inside of this packaging shell. With a plastic AAW “buckle” logo, it reminded me of a jewelry box setting, flipping open to reveal a secure foam insert with W900 shells placed inside of precise cutouts on one side and the case with accessories and warranty/refit form on the other side.

I’m always curious about flagship IEM packaging, and anything different and original gets my attention. The whole packaging was compact and not as flashy, and yet had a premium presentation when you split open that box.


Inside you will find a selection of typical accessories, such as cleaning brush, flight adapter, and 1/4″ adapter. While cleaning brush is necessary, adapters are usually fillers. Also, since I received a universal W900, it came with 3 pairs (S/M/L) of generic black silicone eartips.

The included case is roomy enough for W900 and can easily accommodate a thick aftermarket cable. But the case itself was generic. Also, included was a user handbook, a warranty (2-year limited warranty), and a refit form (for CIEMs, 60-day refit guarantee). Personally, I wish there would have included a more premium case, something more original considering flagship status of W900. But either way, the included case works fine and provides a good protection for W900.


Included with W900 is Null Audio Ethos detachable cable which has 4 inner-twisted SPC conductors and standard 2pin connectors. The cable has a right angled 3.5mm TRS plug with a semi-transparent frosted finish connector housing, NA logo plate, and a nice short strain relief. All 4 conductors are kept separately down to the plug where grounds are joined.

The cable itself is very soft and pliable, hardly any microphonics. It has a nice rubbery y-splitter which matches the frosted finish of the connector plug. Chin slider also has a similar rubbery material and a unique design where one of the sides has a slit to separate cables, probably for a safety reason if you need to quickly split it apart.

As you get closer to 2pin connector, you have a pre-shaped soft earhook which is “terminated” with another rubber mold piece. The housing of 2pin connector is very ergonomic and slightly angled for a more natural shape around your ear. W900 shells I received had a recessed 2pin socket, and there was no issue with a connector insertion. The only complaint here that L/R marking is very hard to see. Adding a red/blue dot on Right/Left sides would be a good idea, especially if you like to cable-roll to compare stock to other cables.

And speaking of cable-rolling, in one of my recent cable reviews I used W900 with number of my premium cables to test the effect of different wires. By default, with the original SPC cable the sound is smooth and has a warmer tonality. Cable rolling can unlock W900 hidden potentials with improvement in tonality and resolution. Don’t expect a night’n’day changes, but if you want to squeeze out every ounce of the performance, here are some of the premium cable choices and how I hear it with W900. These cables, including PWA 1960 flagship, are available for purchase from Music-Sanctuary.

W900 (stock SPC to No5) – soundstage opens with improvement in width and depth. Bass is tighter and has a slightly better definition (cleaner edges) and a little more impact. Lower mids sound similar, though it felt like SPC had a little more body, being slightly north of neutral while No5 is more neutral; in contrast, upper mids have a little more clarity, more revealing. Treble has a noticeable improvement in sparkle and airiness. Overall, it does feels like a layer of veil was lifted off.

W900 (stock SPC to TWag v4) – soundstage is a little bit wider. Bass extension and impact is very similar, and so does lower mids. I’m hearing a difference in the upper mids being brighter, more revealing, and slightly more forward. Also, more sparkle in treble.

W900 (TWag v4 to Thor II+) – soundstage width (same), but depth has improved. Bass is tighter and has a better definition (cleaner transition edges) and a little more impact. Lower mids are a little more neutral, while upper mids are similar and a little more forward, and similarly brighter and more revealing. Treble has an even more sparkle and airiness. Thor II+ improvement was like No5 and TWag v4 combined.

W900 (Thor II+ to TWau) – soundstage has a similar expansion as Thor II+, wide and deep. Bass is as tight but now is a little less aggressive, more analog with a slightly longer decay. Lower mids are similar, while upper mids are as revealing and detailed, but a little more musical, slightly more organic. Treble extension and definition are similar, but a little less sparkle and a touch less airiness.

W900 (TWau to 1960-2w) – soundstage takes another step toward width expansion. Bass is tighter, remind me of TWau performance while being not as aggressive, but becomes more articulate and layered. Lower mids are more neutral, while upper mids are a little more forward, more revealing and brighter (less organic in comparison to TWau). Treble gains back some sparkle and airiness.

W900 (1960-2w to 1960-4w) – soundstage width and depth are similar, but now it feels like width of staging wraps around you, more 3D expansion. Bass is tight, articulate, layered, and now has noticeably more punch. Lower mids are similarly neutral, and upper mids are as revealing and detailed but now also not as dry and with more depth. Treble has a better extension, some improvement in definition, airiness, and more controlled sparkle. The sound feels more transparent and with a better layering.



When you are visiting AAW website, it’s easy to assume their IEMs are only offered in Custom fit design. After all, even their on-line Gallery only displays pictures of CIEM. But they offer both Custom and Universal versions of their IEMs, and you must submit your ear impressions for the custom model. In my case I decided to go with Universal shell design, but regardless if it’s IEM or CIEM, you are still in control of the design.

Unlike some other manufacturers who offer interactive web design tools, AAW has a much simpler approach. They offer you a printout with Shell Colors and Finishes where you can find 45 different choices, and another printout with Faceplate Designs where you can pick from 36 different choices and 10 logos. Of course, you can submit a custom logo and request something different if you are not satisfied with all the available Shell and Faceplate selections to customize your design.

Regardless of my review sample being universal IEM, due to customization process it really felt like a Custom experience. I was also very pleased with a fit of their universal shell. I was a bit nervous, considering 8BA Drivers and Dynamic Driver, but surprisingly the footprint is relatively small and the depth of the shell is not that bad. Of course, they won’t sit flush inside of your ear, but also don’t stick out that much. Not only the fit, but also the finish of acrylic shell was high quality, in my case it had a transparent red color where you can see all the inner beauty of the design with neatly stacked side by side dual BA high drivers, dual BA mid drivers, quad BA super high drivers, and 9mm dynamic driver.

W900 features TruXross 4way crossover design where the Dynamic bass driver has its own physical low pass filter while BAs have 3way passive crossover. If you look closer, you can clearly see there is one tube coming from DD driver, quad BA super highs going to another tube, and dual BA highs and dual BA mids going to a third tube, where they travel through a nozzle to a 3-bore opening. Each shell also has a cleverly designed/hidden pinhole vent on the side, assuming it’s required for DD.

As far as the spec goes, W900 has an average sensitivity of 107.5 dB, making it quite an efficient and hiss-free IEM, and 16ohm impedance which is suitable for a portable use. Of course, isolation of Universal shell will depend heavily on a selection of proper eartips. Over years I accumulated multiple dozens of different eartips, and for W900 I found a nice silicone hybrid pair with a red stem and white cap to match the color scheme of the design. The isolation was excellent, like I was wearing CIEM, so I wasn’t surprised by AAW spec of 26dB. Frequency range spec of 18Hz to 40kHz is impressive on paper, and you will see from my sound impression section that it’s not just a marketing hype.

I have many flagship IEMs from different manufacturers with a driver count anywhere between 8-18, so in general a compact shell with 9 drivers is not a surprise. But considering we are talking about a hybrid design with 8BA and DD, W900 compact shell takes it to a whole new level of appreciation.

The fit.


Page 2: Sound analysis, Comparison, Pair-up, and Conclusion.

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