The key dividing line between smartphones was once as simple as Apple vs. Android. With the operating system selected, the decision tree would move us onto display size, processing power, internal storage and price. And while that may still be the case for the average user, audio folk now have an important issue to ponder: the presence – or not – of a 3.5mm headphone socket.
Keep in mind that the headphone jack is very well established, having appeared on many millions of portable audio players throughout history. I’m talking iPods and other DAPs but also portable CD and cassette players released over the course of several decades. At the beginning of the smartphone era, the 3.5mm jack found its way into every iPhone and most Android phones. It was something listeners could count on regardless of their choice of Apple or Android…
…until 2016. Motorola launched its flagship Z series without a headphone jack. Apple’s iPhone 7 did the same a few months later. From there we saw other manufacturers follow suit: HTC, Sony, Google, and plenty of lesser-known brands dropped the 3.5mm jack on many or all of their devices. Those of us who enjoy music on the go with a nice pair of ear/headphones suddenly had fewer smartphone options to choose from.
LG and Samsung have thus far stuck with tradition, with LG, in particular, throwing a lot of resources into the quality of their audio signal path. But with their Note 10 launching without a physical connector, Samsung may be signalling their intent to switch directions, and rumor has it that the upcoming S20 line will also go that route. It would not at all shock me to find LG taking this same path a few years down the road, if they feel their audiophile focus becomes more trouble than it’s worth.
Prior to 2016, wireless Bluetooth earphones were lacking in one key area: audio quality. There wasn’t a single choice on the market, at any price, that could readily compete with a decent wired set. This made the disappearance of the 3.5mm socket all the more jarring. But several years and many new technology advancements later, I wondered if that was still the case?
I promptly set out to examine the state of the art of Bluetooth earphones. Are they a viable choice these days? I quickly determined that I dislike the styles which have a neckband and/or a wire tethering the right to the left earpiece. Those don’t really feel very “wireless” to me, so I eliminated them altogether. No big loss. I then rounded up the best truly wireless models on offer from Sony, Audio Technica, Bang&Olufsen, HiFiMAN, Sennheiser, Bose, Klipsch, Master&Dynamic, Samsung, etc, and got to listening.
To my ears, the clear winner – and by a substantial margin – is the Sennheiser Momentum True Wireless (US$299). I’ll get to the specifics shortly, but the general takeaway is that the Momentum TW sounds the most like a quality wired earphone. If we shift the focus to battery life, isolation, or some other metric, then certain competitors may be worth a look. But in terms of sonic performance, the Momentum TW stands alone.
Interestingly, Sennheiser doesn’t do anything to deviate wildly from the truly wireless playbook. The Momentum TW is attractive and built to an obviously high standard, but so are many others. The included charging/storage case is perhaps the most unique aspect because it features a (quasi-)canvas outer layer, but that’s about the only distinguishing feature.
The Sennheiser beats out rivals on the effectiveness of its touch controls. While my old-school sensibilities lean toward physical buttons rather than touch controls (all else being equal), for things like skipping tracks or adjusting volume, Sennheiser really nails it with the Momentum TW. They just work as intended, which is not something I can say for every competitor in this category.
My review set of Momentum TW appear to have a slow battery drain even when not in use. If I let them sit unused for a week, they move from full to just about empty. My contact at Sennheiser tells me this is by design, in order to keep them in a state of readiness to instantly use at a moment’s notice. That’s great, but most competitors hibernate with practically zero battery loss and still seem able to wake up sufficiently quickly when needed. This may be my number one complaint about the Momentum TW – not a huge deal to work around but still far from ideal. I’m sure Sennheiser could fix this with a firmware update if they wanted to but they don’t seem to regard it as a problem. Aside from that, battery life is what I consider “adequate” if not really a stand-out attribute. I get roughly 4 hours of listening from a full charge, and the storage case allows for two additional recharges for a total of ~12 hours before needing to see a power source. That’s perfectly acceptable for my usage but it may not work for everyone.
I find myself able to get a solid in-ear fit with the majority of true wireless devices. That’s interesting as traditional wired IEMs can be very hit or miss for my large ears. And that may actually be the key to the Sennheiser’s success – most wired IEMs tend to be fairly small, or at least built to fit the contours of a smaller ear (small being a relative term). Conversely, true wireless models house microphones, batteries and other electronics, making them larger and therefore better-suited to someone like me.
The Momentum TW specifies the basic (and mandatory) SBC Bluetooth codec, but also AAC and Qualcomm’s aptX and aptX Low Latency. That means, despite being lossy codecs, decent sound quality is possible with both Android and iOS devices, and the low latency option makes them a great candidate for gaming, movie watching, or other situations where wireless latency is undesirable (as long as the paired device also supports that codec). Notably absent is Sony’s LDAC, which in my experience can sound quite impressive under ideal circumstances (990kbps mode) but loses steam at the lower tiers (660kbps and especially 330kbps) likely to be experienced during normal use. Frankly, I don’t consider LDAC an essential feature at this point, and I don’t miss it all that much. I wouldn’t mind seeing Qualcomm’s aptX HD or their recent aptX Adaptive codecs on board, though I can’t say for sure how much of a difference those would make during real-world usage. I would expect future iterations of the Momentum TW to explore some or all of these codecs though.
Many wireless IEMs come with a smartphone app which unlocks some useful features. Sennheiser’s Smart Control app is what I consider a middle-of-the-road option. It features a quirky but usable EQ and allows for fine-tuning of options such as Sennheiser’s well-implemented Transparent Hearing mode (which lets the user hear the ambient sound without removing the IEMs), yet those who don’t want to use it aren’t required to do so. I found it best as a sort of set-and-forget option, which is perfect since much of my use after initial setup was with the diminutive Shanling M0.
As is the case with speakers, DACs, and most everything else in the audio world, final performance is not merely about specs but rather the overall tuning. And in this case, Sennheiser extracts a high level of sound quality from the Momentum’s 7mm dynamic drivers. It’s definitely a crowd-pleasing sound signature: dynamic, clean, somewhat warm without going overboard, and with a surprisingly balanced treble that extracts plenty of detail whilst remaining smooth and non-fatiguing. This not merely a great sounding wireless IEM. It is a great sounding IEM, period.
I’ve heard many people say they want a truly neutral sound, but more often than not, their real-world choices lean toward a boosted low-end response. And that’s what Sennheiser tastefully delivers here. It hits with authority and digs plenty deep, which initially caused me to think it was perhaps a tad overdone. Upon further listening, I don’t think that’s really the case, and it may have been an artefact of evaluating a rather lean IEM prior to the Momentum TW. Once my ear-brain adjusted, I found the Sennheiser very enjoyable, even with classical and jazz material which can be sensitive to an exaggerated low end.
The rest of the frequency spectrum is well balanced, with a fluid, almost graceful feel to it. Despite my initial focus on the authoritative low-end, it was arguably the treble presentation that ultimately ended up stealing the show. It’s subtle, nuanced, and simultaneously extended and controlled, which is a key area where most wireless rivals fall short. This even-handed top end also contributes to a focused, well-defined headstage which, while not as expansive as the more costly custom-moulded wired IEMs I normally use, is suitably open for any $299 design, wired or not.
While the Sennheiser Momentum True Wireless is an obvious standout among its peers, I realize that it doesn’t exist in a vacuum. Many of us have LG, Samsung or other brands of smartphone which (for now at least) still offer the classic 3.5mm jack. We, therefore, have many more options. As good as they are in their category, how would the Momentum TW stack up against a more traditional wired competitor like the excellent Campfire Audio Comet.
The Comet’s $199 price tag – $100 less than Momentum TW – initially seems unbalanced, but I figure A) wired designs are inherently less expensive than their wireless counterparts, which should be accounted for in this comparison, and B) the Momentum TW is frequently available at lower prices, making the difference less pronounced. I’ve seen it sell for $250; even lower from time to time.
I seem to hear the Campfire Audio Comet as John Darko hears it. Check out his video review. While not being the most hyper-accurate tool for fussy audiophiles, they nonetheless check all the sonic boxes in terms of musical engagement, drive, and energy. And despite being fairly compact overall, I find their somewhat old-school, cable-down design to be very comfortable.
Note that to even the playing field, I fitted both IEMs with aftermarket foam tips from Dekoni Audio – their Mercury tips to the Comet and their Bulletz TWS to the Momentum TW. Dekoni says both models use the same slow rebound foam technology, with the Bulletz TWS being more shallow in order to properly fit true wireless IEMs; crucial when dropping them back into their charging case. Campfire already includes some nice foamies with the Comet but the Dekoni Mercury tips seal better in my ears, leading to an overall improvement in dynamic contrast as well as comfort. Sennheiser only includes silicone tips for the Momentum TW so the foam Bulletz are a welcome addition – again with better isolation which leads to improved bass texture and resolution across the board. Both Dekoni models are also washable which makes them cost-effective solutions over the long term.
Before going any further, it’s important to address the inherent differences between these two models. I’m not necessarily talking about the Comet’s use of a balanced armature driver versus Sennheiser’s dynamic driver (sill a relevant point) but the nature of a wired IEM’s source device influences.
With Sennheiser’s Momentum TW, my only concern was Bluetooth codec support. It matters not whether I use a flagship $999 Samsung or the $109 Shanling M0 – sonic performance is identical when using aptX. Using an iPhone means AAC. To my ears, it steps down slightly from aptX’s high (lossy) bar but is still pretty satisfying overall.
Meanwhile the Comet, like any wired IEM, is more source dependent. My basic Motorola G6 phone sounds inferior to my Samsung Galaxy S10, which itself takes a back seat to the audiophile-oriented LG G8 thinQ. And then there’s the option of using a dedicated high-end DAP or even desktop system which can bring the Comet to new performance heights. The takeaway? Sennheiser easily hits its maximum performance threshold but remains stuck there, whilst Campfire’s IEM has higher minimum standards yet offers room to grow. For this comparison, I applied the Shanling M0 to both models — it gives excellent wired performance for the money and features Qualcomm’s aptX on the wireless side. I also broke out the iPhone 6S, which to my ears was the pinnacle of Apple’s headphone output quality (I agree – Ed). Anything newer requires a Lightning dongle which offers passable but unremarkable sound.
These two IEMs make for an interesting comparison. And while I really enjoy each model, switching back and forth can be a jarring experience.
Starting with the Sennheiser: I love the low-end authority and extremely smooth, well-controlled treble. Switch to Comet, the highs initially seem overly energetic – at times downright “splashy” – and the general presentation feels reedy and tonally thin. How had I enjoyed this previously? Such is the power of immediate contrast. And yet we know quick fire A/B switcheroos can be misleading. It’s the long-term comparisons that matter.
After logging some time with the Comet, things go from bad to decent to pretty darn enjoyable. Their upper-midrange energy becomes infectious, hooking me into the music in a way the Momentum TW never could. Transients are lively, and there’s a sense of space which feels more accurate – though not necessarily larger than the soundstage produced by the wireless competitor. Low-end kick is plenty satisfying, and I find myself thinking that only a true basshead would need anything more than what Campfire Audio offers here.
Switch back to the Sennheiser and I immediately feel underwhelmed by the presentation. It’s just so dull; lacking in energy, speed and bite and, perhaps, trying to overcompensate with warmth. But as before, I listen longer and things start shifting into place…bass is certainly large but also impeccably well-controlled and the pacing isn’t actually as lumbering as I initially thought. There’s a hint of sweetness to the midrange that I hadn’t noticed before and that smooth treble means we can listen all day without fatigue. I’m hooked. Then I switch back to Comet and the cycle repeats.
As with any direct comparison each model will have its strengths and weaknesses.
Sennheiser’s thicker tonality meshes better with Marvin Gaye’s funk-classic “Rockin’ After Midnight”, bringing out the lush body of the Roland Jupiter-8 synth. The Comet feels more ethereal, with an emphasis on the layered percussion and particularly the finger snaps but ultimately it doesn’t get my foot tapping nearly as often. A similar situation plays out with every track on Pantera’s Cowboys from Hell, where the Momentum TW gives us gobs of body and really captures the meaty guitar “chug”. Phil Anselmo’s vocals feel very slightly set back in the mix but timbrally spot-on. Meanwhile, the Comet makes Phil sound almost like James Hetfield – a comparison neither singer would likely appreciate – and places our focus on percussion. I do enjoy the hi-hat and snare drum snap, but the guitar and bass portions just don’t have enough richness to sound convincing.
With other music, the Comet would be my preference. A Fine Frenzy’s debut album One Cell in the Sea is full of beautiful, deceptively complex singer/songwriter/folk-pop, and the Comet does a fantastic job with vocal projection and piano tone. It also places far more emphasis on the finer details, backing instrumentation and layering, all of which makes this music so interesting to me. The Momentum TW comes off as overly congested and, frankly, a bit boring. Switching to Aesop Rock’s underground hip-hop masterpiece The Impossible Kid, I anticipated Sennheiser taking the crown due to its superior bass rumble and tight treble control, so often welcome on less-than-audiophile-quality recordings. But in truth, the Comet more accurately captures the gruff, gritty nature of Rock’s voice, sounding particularly correct on tracks like “Rings” where his voice has a nasal quality — the Momentum TW gloss over this. And while the Sennheiser do a great job with driving bass lines, the Comet also muster impressive richness and thump. The Momentum is enjoyable enough on this selection but only with Campfire’s little Comet does it truly shine.
Other times the comparison ends in a draw, my mood determining preference. Such is the case with Avishai Cohen’s 2008 release Gently Disturbed, in particular, the brain-ticklingly-complex track “Eleven Wives”. The Comet better captures the timing subtleties: the precise interplay of the drum kit and the energetic pace of the piano. Meanwhile, Sennheiser really nails the heft of Avishai’s bass guitar and feels more dynamically alive and more fluid. It’s a classic head versus heart scenario, where Comet plays it more intellectually whilst the Momentum TW captures more emotion. Which one is the right presentation? There’s really no wrong answer.
The True Wireless IEM category is heating up. IFA 2019 and CES 2020 tell us that we’ll see increasing more options come to market in the coming years and will cover a wider range of price points. Some of the high/er-end models will likely take sound quality to new heights. Bluetooth audio technology has reached its adolescence but still has room to grow.
As of right now, the best True Wireless sound found by this commentator to date are the Sennheiser Momentum TW. They comfortably go toe to toe with wired rivals such as the excellent Campfire Audio Comet, which is sadly no longer an option for the majority of smartphone users thanks to the increasing scarcity of a 3.5mm headphone socket. The Comet is arguably still the better-sounding IEM, particularly when used with nicer ancillary equipment, but the Momentum TW put up a very worthy fight and, at times, put the Comet on the ropes. Folks who plan their smartphone upgrades around the presence of a headphone jack may want to finally rethink that approach – Sennheiser’s Momentum TW is the real deal.