Westone Audio AM Pro-X20 Review featured image

Westone Audio AM Pro X20 Review

In today’s review, James tests the performance of the Westone Audio AM Pro X20, which is a dual BA driver universal IEM designed for musicians and stage artists. It is priced at $399.00.

Disclaimer: This is a sample sent in exchange for our honest opinion. Headfonics is an independent website that does not have any affiliate links. We thank both HiFi Headphones UK and Westone Audio for their support. 

You can click here to learn more about Westone Audio IEMs we have previously assessed on Headfonics.

Note, that this article follows our current scoring guidelines which you can read here.

Westone Audio AM Pro-X20 Review featured image
Westone Audio AM Pro X20 Review
Specifically tuned to excel in the vocal region, the Westone Audio AM Pro X20 offers striking separation and impressive clarity, providing a clear and immersive vocal imaging experience. Its special filtering implementation allows it to seamlessly function as both a stage monitor and an IEM for everyday mixing tasks.
Sound Quality
Comfort & Isolation
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Good vocal separation
Unaltered tonality
Ambiance pass-through feature
Slightly bass-shy
Limited extension
Award Score

Following my previous AM Pro X30 universal IEM review, today’s focus is on the Westone Audio AM Pro X20 which is positioned just below the AM Pro X30 and priced at $399.

Like its bigger brother, it is also equipped with Westone Audio’s Ambient Patented Technology designed for both stage and monitoring applications.

This is not just a tool for pro audio users. It is also positioned for music lovers, being one of the very few products that allow the ambiance to leak through without compromising the frequency response.

Westone Audio AM Pro X20 ambient technology
Copyright Westone Audio 2024

Tech Highlights

The AM Pro X20 is a universal in-ear monitor featuring dual BA drivers and a passive crossover.

It also incorporates a patent-pending Ambient Patented Technology, which sets it apart from the base Pro X10 model by blending ambient sound and the monitor mix. The IEM has a sensitivity of 119 dB @1Khz 1mW and an impedance of 27Ω @1kHz.

What is Passive Ambient Patented Technology?

This unique feature allows a controlled amount of ambient sound to pass through, enabling performers to engage with the audience while protecting their hearing through earplugs.

Putting it simply, when you are in a band practice or rehearsal, you don’t need to take your earphones off to listen to what your teammates say.

The filter module, located under the transparent housing in a dark blue color, is designed to attenuate ambient sound by 10 dB. This means that you can still hear sounds from your surroundings at ease when performing on stage or practicing.

Even if you’re not a musician, the AM Pro X20 can be a great solution for listening to music at work while remaining aware of your surroundings. With this earphone, you can still hear someone calling you even when the music is playing at a relatively high volume.

The inclusion of a pass-through filtering vent in the AM Pro X20 makes it one of the few earphone designs that offers this feature. This is particularly beneficial for individuals who may feel uncomfortable with a completely closed design due to the pressure that can develop within the ear canal. 

Westone Audio AM Pro X20 design


After reviewing over 10 unique Westone Audio IEMs over the last few years I can Westone Audio IEMs are invariably always compact yet stylishly designed.

The AM Pro X20 continues this tradition and features a transparent housing that fits a logo badge, which is the Passive Ambient filter. The tooling quality is excellent as suggested by the clarity of the plastic parts and there are no visible molding marks.

Additionally, the inner structure incorporates a piece of green skeletal component that houses the drivers, which makes the design even cooler.

Westone Audio AM Pro X20 nozzles

Comfort & Isolation

One other trait from reviewing Westone Audio IEMs over the last few years has been the excellent levels of comfort incorporated into their design approach. The housings are meticulously engineered to have a small profile while maintaining durability.

The AM Pro X20 showcases this commitment to comfort. Its extended nozzle and compact body profile allow for a snug and stress-free fit on the outer ear. You can wear them for hours without discomfort or fatigue.

Additionally, the cable of the AM Pro X20 is also feather-light, further enhancing the overall comfort. It can be easily tied at the back of the neck, ensuring it remains discreet and hidden from the audience’s view for professional users, which is great for the gym as well.


The AM Pro X20 comes with a comprehensive range of accessories to enhance the user experience. It includes 5 pairs of patented Westone Audio Ergonomic foam tips and 5 pairs of silicone tips, available in multiple sizes for different ears for optimal fit.

The foam tips are very dense in texture and allow more solid delivery of the bass to my ears, as a result of a better seal. The other silicone tips provided are also well manufactured and there is no need for adjustment after hours of listening.

Westone Audio AM Pro X20 paired with xDuoo XD05 Pro

Stock Cable

The AM Pro X20 is equipped with the T2 cabling system, featuring the sleek black BAX cable as the default choice.

This cable is crafted using silver-plated copper wires and incorporates a 360-degree rotatable Estron T2 connector. The T2 connector is renowned for its sweat-proof performance and enhanced reliability, making it particularly suitable for stage use.

The cable itself is constructed from ultra-low resistance tensile wire that is reinforced with special aramid fiber. Its twisted design effectively reduces cable noise, ensuring a clean audio signal.

Additionally, the cable can be conveniently wrapped and stored in the compact and waterproof Pelican case included in the packaging, without any risk of tangling.

Notably, the AM Pro X20’s stock cable is significantly lighter than most cables, and it provides a comfortable wearing experience without causing any stress on the ears.

Considering its reliability and practicality, the stock cable option of the AM Pro X20 is regarded as one of the more robust cable choices for IEMs.

Westone Audio AM Pro X20 accessories

Packaging & Accessories

The AM Pro X20 is accompanied by professional packaging, which includes a compact waterproof Pelican carrying case featuring an air release valve. This case provides secure storage and protection for the earphones and accessories.

Inside the packaging, you will find additional items such as a logo sticker, a soft pouch, a user manual, and cleaning tools.

As aforementioned it also includes a generous assortment of 10 pairs of tips, allowing for optimal comfort during extended listening sessions. There is also a cable binder, which can be used to neatly tie up the cable when it is not in use.

Sound Impressions

The following sound impressions of the AM Pro X20 were created using a mix of the RME ADI-2 Pro, the FiiO Q15, and the FiiO R9 for both decoding and amplification. 

Passive Ambience

The AM Pro X20 differs from conventional in-ear monitors (IEMs) in that it incorporates a vented design.

However, the passive ambiance feature does not significantly impact the listening experience when used outdoors. It becomes more noticeable in environments with loud ambient noise, such as when people are talking or shouting, especially from both sides of the listener.

This feature allows for better stage interaction, as the listener can still hear the crowd or from people around and maintain awareness of their surroundings.

Despite the vented design, the AM Pro X20 does not sound like an open-back earphone or headphone, and it still delivers sufficient bass power and a rather balanced tuning with the sub-bass being slightly thin in body.

As a side note, you can test the effectiveness of the filters by covering them with your fingers. By doing so, you will completely block out the frequencies that penetrate through.


The AM Pro X20, much like its counterpart, the AM Pro X30, is tuned to provide a clean response and commendable vocal separation. The primary focus is on vocals, ensuring they take center stage with clarity and prominence.

This tuning is particularly suitable for mixing or stage use, as it allows the lead singer’s vocals and the intricate details in the treble range to be distinctly heard. The midrange is presented smoothly, avoiding any excessive thickness, and revealing more details in the vocal range and the upper frequencies.

The transparent housing of the AM Pro X20 showcases a substantial bass driver, which not only adds visual appeal but also contributes to an airy bass response.

It’s worth noting that the vented design or the tuning focuses more on the midrange frequencies and maybe that is why the bass doesn’t extend very deep.

Overall, the tuning of the AM Pro X20 maintains a V-shaped signature, prioritizing clarity, and detail retrieval.


As previously mentioned, the AM Pro X20 is equipped with a large BA driver dedicated to bass reproduction. This driver focuses on delivering textured and impactful bass while maintaining good clarity.

The bass presence is quite controlled, striking a balance that allows the bassline to be easily picked out within a track without overpowering the mix. Different elements of the bass are distinguishable without any particular frequencies sounding overly thick or flat, and it has a moderately fast decay and sufficient layering.

In noisier environments like a bustling mall, it may be harder to allow bass instruments to be picked out from the track. If you want to focus on bass instruments, then you might want to equalize the lower register for a stronger presence as the vented design undeniably lets more of the upper frequencies pass through.

Westone Audio AM Pro X20 paired with FiiO Q15


The AM Pro X20 presents vocals smoothly and clearly, with a pleasant touch of warmth. It offers a relatively neutral vocal presentation, placing more emphasis on the upper frequencies of the vocal line while maintaining body in the sub-bass region.

Other instruments across the midrange are also adequately weighted and delivered with clarity. The vocals cut through the mix effectively, as the bass does not bleed through, allowing for a clearer vocal image.

In the upper mid-range, there is a slight rawness that can be perceived. However, this characteristic captures more details, particularly with string instruments, accentuating nuances that may be attenuated in other headphones, resulting in increased sharpness.

When compared to the AM Pro X30, the X20 feels more like typical monitoring speakers, making it a more ideal choice for those seeking clear vocal reproduction, such as when listening to talk shows. It provides an uncompressed and revealing sound, which can be beneficial for mixing purposes.


The treble on the AM Pro X20 has a noticeable presence, with less emphasis on the low end. The tuning is clean, effectively reducing sibilance and peaks in the upper frequencies.

This allows for extended listening sessions at higher volumes without experiencing fatigue. There is a satisfactory amount of air in the sound, which, combined with the leakage of ambiance, contributes to a dynamic and immersive output.

This characteristic makes the AM Pro X20 suitable for various music genres, as it doesn’t sound confined or boxed.

In noisy environments or at higher volumes, the ambiance remains subtle while letting you be aware of the surroundings. The overall balance of the AM Pro X20 is well-maintained, providing sufficient dynamics in different situations.

For instance, in a crowded coffee shop, you can still hear some of the surrounding sounds while enjoying jazz music from your player, and I can hear what my friends say even when the song is on at my listening volume level.


The special vented design as well as the less focus on bass frequencies contributes to bringing in more air in the treble to the mix, which makes the output sound fairly expansive while rendering the vocal clearly with a centered image.

There is a sufficient definition of power and separation, and the monitoring tuning approach extracts details in the vocal, allowing the vocal line to be heard on stage or to reveal flaws during mixing works.

Due to the vented design, at low volume, you may hear more ambient noises and that may sound less natural, though at higher volume the AM Pro X20 behaves more alike conventional earphones.

Click on page 2 below for my recommended pairings and selected comparisons.

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