Westone MACH 20

Westone MACH 20 is an entry-level IEM of the manufacturer’s latest series. It’s packed with dual balanced armature per side and priced at $399.


Like iPhone is the product you think of when someone tells smartphone, or Jeep Wrangler when someone tells about the off-road vehicle, like the Westone products are the ones when someone tells about on-stage in-ear monitors. 

The company was established in 1959, almost 40 years ago they invented the first in-ear musicians’ monitors and the first balanced armature driver as well, that’s a serious heritage. Without them, we probably couldn’t enjoy thousands of different IEMs, which for us, the Ear Fidelity crew, would be a big loss, because we all are big fans of Hi-Fi on the go.

Today’s reviewed gear is the second lowest IEM from Westone’s latest universal series – MACH. What’s interesting, each piece from the series looks exactly the same, the only difference is the number on the left earpiece, from 10 to 80, the biggest difference is the internals, from a single balanced armature in MACH 10 to eight drivers in MACH 80. If you’re willing to spend more money, you can read Michał’s review of MACH 60 here, but if you’re interested in the “entry-level” model (at least in terms of the Westone MACH series), then keep reading this review.

Packaging, Tech and Comfort

I’ve received the MACH 20 in a sample package – zip lock bag and bubble wrap to secure the earpieces. Unfortunately, I can’t say anything about the retail packaging from my perspective, the only thing is Michał’s report from CanJam, where he was talking with the Westone representative.

So when you will buy the headphone, inside the box you will find a big selection of tips (silicone and foam ones), a Pelican case (the original one), a cloth, a cable, and the IEM. The case is great, it’s fully waterproof and very durable, it would probably have survived a plane crash.

The cable is, and it’s the only positive thing I can write about it. It’s got proprietary connectors, so you can’t replace it with aftermarket options. It’s very thin, but the manufacturer claims it’s durable as well. It’s also not the softest cable I’ve ever used. But let’s stop bullying the cable, let’s move to better parts of the headphone.

So now the tech, MACH 20 has 2 balanced armatures in each earpiece. The sensitivity is rated at 110dB and the impedance is about 96 Ohms. That’s all you can read on the website, it ain’t much technical-marketing bs on their website, but it’s a gear for the professionals. They only need IEMs to be comfortable and don’t color the sound too much. In that use case, Westone IEM works very well, I could sit listening to them for hours (I think I also could jump, workout, or dance and the IEM would keep in my ears, but I’m lazy AF, so I didn’t test them properly in that scenario), about the sound I will write later, but it’s fine as well.

Design and Build Quality

As I wrote above, Westone MACH 20 shares the shell design with other representatives of the MACH series. The build quality is pretty good, for $400 you’re receiving the build quality of the headphone that is worth $1600 – that’s a deal (as I mentioned above MACH 80 has exactly the same shell design as MACH 20). The earphone is made of good quality plastic, unfortunately, the description on the website is brief and there is no mention of the type of materials used. The finish of the earpieces is superb, you can see the lines where shells are separated, but it’s fitted so tight that I can’t nearly feel it with my fingertips.

On the inside part of the shell, there is a Westone logo, red on the right shell and blue on the left one. Thanks to it, the recognition of the channels is super easy. I wish more manufacturers would use similar methods to differentiate the earpieces – a simple solution for first-world problems.

What’s worth to mention, the nozzle is very narrow, so if you have an issue that most headphones are too big to fit your ear canal, then the MACH series can solve the problem. You may wonder why most manufacturers produce so large nozzles. That’s because maybe it’s not the most comfortable for users, but definitely easier to implement for sound engineers, but engineers from Westone have nearly half a century of experience in designing IEMs and they know a lot of tricks on how to make earphones sound and fit perfectly.


I’ve written that the biggest difference between IEMs from the MACH series is the number of drivers, but this implies the sound difference is huge as well. There are plenty of sound signatures in the lineup, but today’s review star – MACH 20 is the bassy one.

Let’s start with the bass, which sounds like a typical bass reproduced by balanced armature drivers. What does it mean? It’s very fast and precise, but it roll-off quickly, so the sub-bass isn’t audible properly. Normally when I’m listening to warm-sounding headphones, it’s safe to choose some electronic music like French 79, or Crooked Colours, but due to the character of the sub-bass, I had a problem because this kind of music loses a lot, when it’s not powerful enough. 

The midrange is recessed, but it still has an amazing texture and it’s very natural. While listening you need to focus on it, otherwise, it will be overwhelmed with the lower frequencies. The way it’s being reproduced with MACH 20 favors the instruments and vocals in the lower midrange. That is why Agnes Obel probably won’t show you what these headphones can do, but Nick Cave in “Where the Wild Roses Grow” makes me goose-flesh. His voice is full-bodied with an amazing timbre.

And the last, unfortunately, the least as well – the treble is very warm and recessed. The details are lacking as well. If you’re looking for a headphone to put your listening experience on the next level in terms of the resolution and details in the top end of the audible frequency range, then keep searching, because it sounds like it’s covered with a fluffy blanket, or from behind a heavy, beefy veil. If you would like to joy your ears with the sound of cymbals in “Dronning Fjelrose” by Hoff ensemble & Helene Bøksle then there are a couple of better IEMs available on the market, but if you are looking for an IEM that you can listen to to even terribly produced songs for hours, then go for it.

Okay, I hurried up, and nearly forgot about the soundstage, which is realized in a very correct way. Nothing fancy, but also nothing wrong, depth, width, and height are pretty similar so no direction is too far nor too close, the positioning is good as well. I don’t have anything to complain about here. My reference song for checking the soundstage is “Bubbles” by Yosi Horikawa, and what can I say? It sounds as I could expect, the dimensions aren’t as wide and deep as when played back with HiFiMan Susvara, but the layers of the sound are pretty impressive.


Craft Ears Four

Craft Ears 4 is a Polish CIEM fitted with 4 balanced armature drivers, priced at €625 (price in US dollars should be similar). In terms of design, it’s hard to compare, because when ordering CE4 no matter if universal or custom fit, you can completely customize the design of the shells, but it’s made with 3D printed resin.  When comparing with CE4 universal fit the biggest difference is the nozzle diameter, more popular among IEMs, so if you already have some aftermarket ear tips, you will be able to utilize them, but it won’t fit the very narrow ear canal, then the only solution will be custom in-ear monitor made from your immersions.

Now the sound, when I used Craft Ears 4 for the first time, I couldn’t believe there are only balanced armature drivers inside. 

The bass is very powerful and fast and it can go very low, like it was produced with a dynamic driver, in that case, CE4 is out of the reach of Westone MACH 20, which also reproduces very fast and powerful bass, but the lowest end nearly doesn’t exist.

The midrange, in this regard both headphones are not the greatest. The midrange of both IEMs is recessed, but the way it’s reproduced is slightly different. The CE4 is very technical, and the midrange is very detailed and well-textured, while Westone MACH 20 has a warmer and smoother midrange, with more charming vocals.

The treble, huh, that’s tough. The comparison to this place was pretty even, but regarding the highest frequencies, I can write that the Craft Ears 4 is amazing – very detailed, but perfectly balanced so it’s very pleasant to listen to, while Westone MACH 20 is definitely not tiring, but if you’re looking for good resolution, then pick CE4.

When comparing the soundstage we can see two different approaches, MACH 20 reproduces the soundstage ultimately precisely, while Craft Ears 4 does it more spectacularly. The soundstage of the Polish IEM is way wider and slightly deeper, but the positioning isn’t as precise as while using MACH 20.


Westone MACH 60

Westone MACH 60 is a universal in-ear monitor priced at $1099. In terms of build quality it’s exactly the same gear, if someone blindfolded you, and asked to determine which IEM is which without listening to them, you would probably have a big problem.

In terms of sound they differ completely, MACH 60 has a balanced signature, while MACH 20 is warm and bassy.

The bass of the 60s is definitely not as pushed forward as one of the 20s, but both lack the lowest sub-bass, but the whole bass is pretty fast, I would say that this part is the typical bass reproduced by the balanced armature. I would say “it’s just physics” but the next comparison will show that it’s possible to make BA sound beefy.

The midrange is definitely the strongest part of the MACH 60, it reproduces voices in an amazing way. Unfortunately, the cheaper brother sounds cheaper in that term, the midrange is definitely recessed, and lacks much when compared head-to-head with the 60s but, let’s not be that harsh to MACH 20, it’s $700 cheaper than 60.

When comparing the treble, it’s another place where MACH 60 sparkles again, it’s much more detailed, while the treble reproduced with MACH 20 sounds like it’s hidden under the blanket, but I mean a very fluffy blanket.


Westone MACH 20 is a very comfortable IEM. If you’re looking for universal in-ear monitors to use during performances, or earphones to use while doing some sports, it’s a definitely good choice for you.

In terms of sound, it’s a very specific gear and it may not fit everyone. If you’re looking for a warm-sounding IEM that can be used for hours without fatigue, then go for it, but don’t expect the edges of the audible frequency range to be very impactful.

Gear used during this review for sake of comparison and as accompanying equipment:

  • Headphones: Bqeyz Summer, Campfire Audio Vega 2020, Craft Ears 4 CIEM, Dan Clark Audio Aeon 2 Noire, Dan Clark Audio Ether C Flow 1.1, Focal Elegia, HiFiMan Ananda,, Meze Advar,
  • Sources: Fiio M11 Pro, JDS El DAC II + SMSl SP200, SMSL SU9 + Topping A90, MacBook Pro 14, iPhone 13 Pro with apple lightning DAC/Amp

Disclaimer: Big thanks to Westone and John from KSDISTRIBUTION for providing the MACH 20 for this review. This review wasn’t influenced by anyone, all of the above is my subjective, honest opinion.