Wearing truly wireless in-ear monitors is a liberating listening experience. That magic combination of small size, light weight, and a total absence of any cables to get caught somewhere means you can be active and still enjoy your favorite tunes in high fidelity. There are many Bluetooth headphone designs that claim to be wireless, but the earbuds are connected with a cable. In contrast, the subject of this review—PSB M4U TW1 True Wireless Earphones ($149 on Amazon)—are blissfully cable-free.
Notably, the price point of the M4U TW1 is ten bucks less than Apple’s famous wireless IEM offering, EarPods ($159.99 at Best Buy). I have both, and it’s quite clear the two products have different design priorities and consequently deliver divergent user experiences. Read on to see if PSB’s take on wireless Bluetooth IEMs matches your expectations and needs.
Features and Specifications
These are Bluetooth v4.1 IEMs featuring a sporty IEM design that wraps around your ear (keeping it firmly in place) and is water-resistant. This is the first wireless earphone from PSB Speakers and it enjoys the benefits of four decades of acoustic research performed by company founder Paul Barton.
Frequency responses specified at 20 Hz to 20 kHz and battery life is up to 5 hours. Time to full charge is two hours and you can charge each earphone with a standard micro-USB cable and they come with a Y-adapter that charges both IEMs at one time. PSB includes four sets of silicone ear tips in the package, and a carry case.
The M4U TW1 earphones come with a USB charging adapter cable that charges both at once.
M4U TW1s feature a built-in microphone so you can use it to make calls or speak to a virtual assistant. It also has touch-sensitive control for pause/play and track skipping, as well as answering calls.
These earphones work with the A2DP Bluetooth profile; with it, compatible devices offer higher quality sound than standard Bluetooth audio streaming.
Here’s the key thing about the M4U TW1: They sound good and they absolutely will not fall out of your ears during vigorous exercise. You can’t say the same for Apple’s wireless EarPods; the reality of Apple’s IEMs is that they will pop out of your ear if jostled just the right way, it happened to my spouse as she was inline skating a few weeks ago. But with these PSB M4Us, the wrap-around design helps them stay put no matter what you do. And frankly, since I would choose another style headphones (typically over-ear sealed like PSB’s M4U 8 Wireless Active Noise Cancelling headphones)
The “large” eartips were the best fit for me, so that’s what I used. It’s good that PSB included four sizes because with IEMs the fidelity you get—especially when it comes to deep bass—is contingent on getting a good seal. That seal also provides some isolation from external noise, which is another design difference between these IEMs and Apple EarPods (which provide no seal at all).
PSB M4U TW1 earphones. The PSB logo is a touch-sensitive control.
To the extent that I perform measurements on headphones and earphones, the main thing I’m looking for is how well they do in terms of bass extension. Response gets trickier to measure as you go up the Hz ladder, and besides you can use EQ to get the tonal balance you seek, but you can’t add bass when the ability to reproduce it does not exist. With the help of a miniDSP E.A.R.S. rig, plus my own ears, I determined that these headphones do indeed deliver the 20 Hz to 20 kHz response promised by the specs.
Using my own ears to judge sine waves generated by REW, I concluded the quoted 20 Hz to 20 kHz figure is a real reflection of what M4U TW1 earphones deliver at real listening levels, without audible distortion. Truth be told, these earphones will pump out 18 Hz and even 16 Hz tones, but you can hear some accompanying distortion whereas by 20 Hz the sound cleans up and becomes a pure tone. It’s hard to imagine anyone being disappointed with the bass performance of these earphones, wireless or not. And they are so accurate I’d recommend them to any music producer who would be inspired by taking their laptop to a park and sitting in front of a beautiful view while they compose a track; it’s totally liberating and you can trust what you hear.
Aside from the laptop where I run Ableton Live and compose music, I used a Samsung Galaxy Note 8 and an iPad Pro 10.5″ for the bulk my listening, with Tidal HiFi serving as my primary music source.
Critical listening was encouraging, the overall sound is similar to what I hear from high-performance headphones with highly linear response (like NAD’s excellent VISO HP50 that are $179.99 on Amazon). No surprise, Paul Barton had a hand in how those excellent cans sound. If you prize accurate sound with deep bass in wireless IEMs then you’ll want to get these instead of EarPods. Quick aside… I own EarPods and use ’em to talk on the phone, which they are great for. But for music, there’s no competiton… these PSBs are soooo much better that it’s not even funny.
With PSB’s high-fidelity offering, reality and specifications align quite nicely, you hear big sound that goes deep. I tasked the M4U TW1s with playing Meat Beat Manifesto’s brutally industrial Answers Come in Dreams, which is an album that assumes you have a truly full-range system to properly appreciate. It was nicely rendered by the PSBs, with detail and delicacy that would have you thinking these were wired IEMs of similar cost. And the deep stuff, which is the hallmark of thee album, sounded as weighty and foreboding and brutal and industrial as I could wish for. There’s no notion that what you hear is compromised just because there’s no cord.
Last month I picked up a Ninebot/Segway ES1 electric scooter ($400 at Best Buy) that I’m using a lot to get around. But, Philly’s pothole-filled streets can be a rough ride. Not a problem with these M4Us, they stay in my ears no matter what. And the comfort factor is extremely high, these are IEMs you can wear for hours on end without feeling it at all.
The sound of these IEMs is balanced, detailed, rich, and undeniably full-range. They handled any and all comers music-wise, from the electric energy of Jane’s Addiction’s album Nothing’s Shocking, to the meticulously crafted Fractal Zoom by Brian Eno, with healthy dose of Adrian Sherwood’s (Becoming a Cliché, Never Trust a Hippy) plus the latest joint from The Orb, No Sounds are Out of Bounds. I’m a fan of listening to full albums when the musicianship and production merit the attention, and the M4U TW1s made the listening experience worthwhile.
Another notable thing about these PSB earphones is the range plus the quality of the Bluetooth connection. I live in a Philadelphia rowhouse, and with the TW1s connected to my iPad, which I left in the first floor kitchen, I was able to go anywhere in the house, from the basement to the third floor (and including the backyard as well as roof deck) while maintaining uninterrupted streaming in high fidelity. Ergo, these are perfect for wearing while doing active things at home.
Not only do these earphones play clear and deep, they can pump out some decent dynamics thanks to a fairly high maximum volume. This turns out to be great for laptop gaming and if you enjoy a good session while you’re on the go you’d find the comfort, accuracy and fidelity of the PSB M4U TW1 likely fits your needs.
Sounds effect on games played using my Gigabyte GTX960-equipped laptop were rendered with great clarity and the powerful, deep, clear bass they put out was put to good use in games like Call of Duty: WWII, Horizon Zero Dawn, and GTA 5 (still my go-to game) and just about anything else I threw at ’em that had good sound, and of course you get 2-way communication with a clear microphone. Long story short is these work for gaming on the go, whether it’s a PC, phone or tablet.
The key to finding the right headphones for a particular application is to prioritize. If what you seek from the next pair you buy is a combination of high fidelity, physical durability and secure fit, then you’ll find the M4U TW1 very attractive. The catch is they are not as “slick” as the fruity computer company’s wireless EarPods, which are easier to pair, smaller, lighter and have a charging case (all nice things). But with this design, PSB is giving you the things Apple had to cut, not the least of which is audio fidelity, but also comfort and proper fit.
Look, I do not want to beat around the bush here. Apple did its thing with Earpods and that’s the “standard” the people will use to judge truly wireless IEMs. And from an ease of use perspective, you gotta give the nod to Apple; you can answer the phone using earpods that are charging by just grabbing them and putting them in your ears. The M4U TW1 is not that sort of device. You’ll want to charge them up in anticipation of a proper listening session, whether it’s at the pool, beach, on a bike ride, jog, cross country skiing… it does not matter because the idea is to get into the activity and into the music and not worry about bad sound or losing an earpiece because it falls out of your ear.
When it comes to sound quality, the M4U TW1 has the best fidelity I have thus far heard coming from affordable wireless Bluetooth IEMs and are way ahead of Apple’s offering in this regard. Given this reality, if your budget for wireless IEMS is around $150 and you prize fidelity plus a secure/comfortable fit more than the conveniences offered by wireless EarPods, I strongly recommend the M4U TW1 from PSB Speakers. Affordable wireless IEMS never sounded so good.