Westone AM Pro 20 Review

The AM series offers an in between for those wanting isolation and an ambient headphone. The headphone offers a transparency for environmental content to bleed into what your listening to. An IEM like this offers great options for musicians in practice, worship ceremonies, and those not wanting an isolating IEM.

Westone AM Pro 20 Review


Westone has made the environmental awareness possible from the addition of their proprietary SLED Technology and TRU Audio Filter. Aside from the special tech added to the IEM, it is a standard build using Balanced Armature drivers and MMCX connectors. Like their other Pro model the UM series the cables are reinforced at the connector.


Sound Quality

With the additional Balanced Armature driver the AM series really takes off with the AM Pro 20s. Because of the market audience for the IEM it needs to have an articulate and balanced frequency response. When you have multiple drivers in an IEM one is dedicated to reproducing bass frequency content and the other is for mid range to high end treble content. The end result makes the IEM’s frequency response much more full/detailed and run more efficiently.

Low End

The low end in pro IEMs can tend to come off as a little flat or lackluster because of it’s tamed response. The AM Pro 20 finds good balance between power and detail coming off slightly less full than it could to give proper bass response. Things like bass and kick drums come though transparent and naturally.

Mid Range

Probably the most critical range that this IEM has to conquer. Vocal content, guitar, drums, and pretty much everything has to come through unabridged and detailed. The Pro 20 has a very clear and articulate mid range from the low mids to the upper mid range. The lower mid range comes through slightly warmer than it could, but this is just me being hyper critical. There is good separation of content when this frequency bracket gets cluttered.

High End

While having a limited response of up to 18kHz the AM Pro 20 does a good job of keeping the higher end content in control. While not coming off too brilliant or sharp the high end has a good full presence that helps strings and horns come through the mix well. Reverb and effects have plenty of room to breathe and decay.


The soundstage for many in ears is pretty narrow and it’s something we expect, but the AM Pro 20 has a pretty decent soundstage for an IEM. There is a good sense of depth and placement within the sound field that enables room for additional definition and clarity.

Overall Impressions

Even though I’m not completely sold on the concept of ambient IEMs, that isn’t to say they don’t have their place for use. Places like houses of warship where the musicians are held back by certain technical capacities, or musicians wanting to be able to hear themselves in practice without sacrificing quality can find solace in the design.


If you are needing an ambient IEM then you cannot go wrong with the AM Pro 20s. But if you need more isolation and still want reference sound quality then the UM Pro 20s by Westone are a great substitute. I would not recommend using them in a professional stage environment that has a loud stage volume because of how the addition ambiance would throw off my monitor mixes.

You can find these buds for the best price here:

Audio 46 (Use our promo code, “majorhifi” to get 10% off)


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An Audio Visual Technician based in live music and corporate events. When not mixing your band or awards show he can be found trying to find the best iced coffee or craft beers around town. Contact: morgan@majorhifi.com