STEREO GUIDE verdict
The Bose QuietComfort Ultra Earbuds replaced the QC II after a short build time. The Bluetooth in-ear combines extremely effective ANC with 3D audio.
Pros
- very deep and powerful bass with kick and good precision
- Remarkably good 3D sound with practical head tracking
- The very good wearing comfort also contributes to the impression of natural hearing
Cons
- Voice and overtone reproduction not as convincing as spatiality and bass
- the in-ears are somewhat awkward to remove from the case
- ANC circuit causes reduced signal to noise ratio
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Sound: tonal balance / transparency8.6
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Sound: Bass / Dynamics9.6
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Ease-of-use / Connectivity9.5
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Price/Performance9
The Bose QuietComfort Ultra earbuds in this review are backed by decades of experience with active suppression of ambient noise by means of an inverted correction signal mixed into the audio signal in the headphones. Quiet Comfort from Bose – many air travelers use this term almost as a synonym for mobile headphones with particularly effective active noise canceling (ANC). No wonder, as the Americans were the absolute pioneers of this technology with their on-ear models in the QC series and dominated the segment for a long time.
As early as 1986, Jeana Yeager (no relation to the legendary test pilot Chuck Yaeger) and Dick Rutan took off with the prototypes of the QuietComfort headphones introduced in 2000 in an attempt to fly around the world in the Voyager light aircraft without a stopover. After all, the Voyager designers had to do without any insulation in order to achieve maximum weight reduction.
Table of contents

Long experience with ANC
I also wore first-generation QuietComfort in-ears on flights for many years. It was still wired and had a flat but fairly wide electronic box with a battery in the cable. In it, miniaturized circuits generated anti-noise with the help of microphones to cancel out external noise in the ear. The ANC did create a little noise. But where Active Noise Canceling was activated with a switch on the cable remote control – for example on trains, suburban trains, airplanes or on busy streets – the advantages clearly outweighed the disadvantages.
The QuietComfort ANC was not only outstandingly effective by the standards of the time. It was virtually the mother of all ANCs. When I was out on a date at a street festival with weird but extremely loud bands, the little Bose earplugs were able to eliminate all the noise right down to the deep bass – brilliant. In addition, the specially shaped silicone pads and special tuning make them extremely comfortable to wear. Thanks to the bass boost, the Bose QuietComfort could sit loosely in the ear without the bass suffering as with conventional in-ears. That was a huge comfort gain on long journeys.
Difficult to get to grips with at the beginning
With the Bose QuietComfort Bluetooth earbuds, the brand founded in 1964 by Professor Amar G. Bose near Boston eliminated the biggest flaw: the annoying cable disappeared. The numerous true wireless versions of the QuietComfort series have now eliminated the weak point with the cable and the box. So I was very curious to see how the successor to the QuietComfort Earbuds II would fare compared to the original model in terms of noise and how effective its Active Noise Canceling, which has matured over the years, would be? The previous Bose TWS in-ears largely passed me by thanks to the many subject areas.

The successor to the QuietComfort Earbuds II with improved technology, available in black or white, can be reviewed at the market launch. The outer edges of the Bluetooth in-ears are now matt metallic, but the form factor has not changed: the Ultras are also fully wireless earbuds (TWS) with a stem housing that protrudes downwards, although it is wider and significantly shorter than that of Apple and B&O, for example. However, they can only be pulled out of the charging case with a bit of patience and a bit of skill.
Incidentally, the Earbuds share the product name with the better-known on-ear headphones from Bose, which is likely to cause some confusion when searching for specs or reviews. The new algorithm that Google is so proud of also has a hard time telling the QiuetComfort Ultra Earbuds and QiuetComfort Headphones apart. If you came to this report via search, you can probably tell a thing or two about it…
Useful innovations
In terms of connectivity and music decoding, the Ultras have been significantly upgraded compared to the QuietComfort II: In addition to the previously supported AAC, the QC Ultra also includes aptX Adaptive and aptX Lossless as codecs. This means that both Apple iPhone and Android users can expect high-quality wireless transmission. Until now, the latter have had to make do with the simple SBC codec. Bose has integrated Bluetooth in the very latest version 5.3, so you can expect maximum connection stability.
The new integration of immersive audio including head tracking should justify the higher price compared to its predecessors. The Bose QuietComfort Ultra have position sensors to track head movements and prevent the imaginary sound stage from moving with head movements. The Bluetooth in-ears are said to be able to reproduce a truly spatial 3D impression thanks to a clever immersive room simulation program. To do this, you have to select Immersive Audio with head-tracking mode “motionless” (when sitting in front of a monitor or on the couch) in the Bose Music app. 3D audio can also be used on the move without head tracking (which would overtax the technology) or deactivated completely.
However, the mode with the full range of features costs battery life, which at 6 hours is not too generous anyway, regardless of the case. You should assume a maximum of 4 hours with head tracking. We will discuss the effect of 3D sound and head tracking in detail later in the listening test.


Adaptation to the ear
When it comes to inserting the earbuds into the ear, Bose takes a slightly different approach than the competition: although the Ultra Earbuds also have to close the ear canal tightly, you don’t have to insert them as deeply as other competitors. This makes them noticeably more comfortable to wear, but also carries the risk of the earbuds coming loose from their optimal fit if there is significant movement.
To prevent this from happening, the manufacturer supplies additional silicone rings with small fins alongside the oval adapters for the ear canal. They grip inside the auricle to prevent them from falling out. You should take your time to find the optimal combination for each ear, then the Bose QuietComfort Ultra earbuds offer an almost unbeatable combination of wearing comfort and secure fit. This is especially true as the new in-ears sat perfectly on me with the standard pre-assembled ear adapters – in the sense of minimal pressure and, at least when walking around beyond sporting activities, also sat more securely in the ear canal than many other TWS in-ears from recent reviews.
Easy entry
The US brand, which is known for its user-friendliness, has done a very good job with the app. A reference to the matching app with QR code in the Apple and Google app stores can be found on the inside of the lid of the plastic-free packaging. The Bose Music app was still on my iPhone because of the soundbar review conducted jointly by STEREO GUIDE and LowBeats with the Smart Soundbar 600. Bose conveniently combines different product categories in the Music app. The older Bose Connect app is not suitable for the QC Ultra. If you use an Android smartphone or tablet, you can look forward to Google Pair, which makes the Bluetooth pairing required to use the app even easier.


The name of the Bose
In the Bose Music app, there are gadgets such as name suggestions for individual naming of the headphones. Want some examples? How about “Bass Bumper”, “Earphoria”, “Moonwalk” or “Milkshake” (where did you get that idea?) or “The Flash”. Objective as we reviewers are, we decided on “Bose QC Ultra Earbuds”.
Bose Music app, you can also customize the touch commands of the touch-sensitive surfaces of the two earbuds to your liking. These shortcuts can be used to control playback without taking the phone out of your pocket, activate the Siri or Google Assistant voice assistants or switch the ANC between noise suppression and transparency function to perceive the environment. A smart trick also contributes to the dialog with the outside world: If you take one of the two in-ears out of your ear, the other automatically switches to mute. To answer phone calls, simply tap the QC Ultra in your right ear. Nice feature: The Bose even announces who is calling, provided the name of the number is stored on the smartphone. The language of the announcements can be selected in the app.
Another interesting feature also deserves a mention: the Custom Tune Test. After insertion into the ears, the two Bose play a sweep. With this Earbud Seal test, the Bluetooth in-ears check the correct fit. You can also call up the test again at any time in the app. We pulled out the left-hand QC Ultra and put it to the test with the automatic check: After the test, a warning appeared for the corresponding earbud.
Outstandingly good transparency mode
Bose went its own way when naming the ANC functions: Activated ANC is hidden behind the name “Quiet”, the transparency mode behind “Perceptible”. To our great surprise, the usual, often extremely strong noise was not perceptible in “Perceptible” mode. This negative side effect unfortunately accompanies the playback of announcements or conversations looped through the integrated ANC microphones in our reviews with headphones from other manufacturers. The Bose QC Ultra really sets the standard here. The in-ear even gives the impression of a natural perception of the surroundings without a technical device in the ears.
You can even select a number of names from a list for your own scenarios and then adjust the effect of Active Noise Cancelling for the relevant occasions, such as outdoors, using a slider in the app on the screen.
As outstanding as Bose has solved the problem of looping through ambient noise when required – one shortcoming seems to me almost more pronounced than with the milestone QC 20 described at the beginning: Bose has cut the annoying lines in the last 10 years, but has not eliminated the noise. Here, the current QC Ultra obviously pays the price for its extremely powerful Active Noise Canceling, which is still incredibly effective against ambient noise. Such a blatant suppression of external noise is obviously not possible without side effects, even with the most modern means. This may seem paradoxical to the user: in transparency mode, the QuietComfort outclasses most of its competitors, but with ANC, of all things, it is noisier than most others when you actually want total silence. Even the QC 20, which is ancient by today’s standards, can easily keep up.



3D sound and noise canceling in a practical test
That brings us to the listening and practical test. What the ANC achieves is truly remarkable after the experience with all the noise-canceling headphones of recent times. For example, I was able to stand directly in front of our Teufel Boomster , which is always used as a comparison in the Bluetooth mid-range, and turn it up when music playback via the in-ears was paused. Even at level four, nothing but a slight whisper reached my ear.
Such acoustic stunts are completely unthinkable with other earbuds in this price range, such as the Denon PerL Pro we have just reviewed. In any case, the Japanese in-ears derived most of their noise reduction from mechanical insulation. The active noise canceling only made a marginal difference in the upper bass. However, the decision not to do so paid off with comparatively low background noise when ANC was activated.
The 3D effect of the QuietComfort Ultra earbuds is just as impressive as the external noise suppression. The algorithm that Bose uses for the spatial processing of stereo recordings does not get the music out of your head to the extent that you can experience music just like in a live concert or at least like with hi-fi speakers. This is also a fundamental problem that we have already addressed in several other headphone reviews.
Magic in the game
But the magic works so well that you feel much less like you’re listening to headphones than usual. The Denon PerL Pro with the immersive mode turned all the way up can’t keep up. It is not so easy to explain in individual points. All in all, when immersing yourself in the music reproduction, if you don’t try to locate the much-vaunted third violinist from the left in the orchestra like a reviewer, you get the feeling that you get from natural listening without buttons in your ears.
In particular, we felt that something was missing after switching off the 3D sound – an effect that I know from the Porsche Panamera with Auro 3D, which I tested years ago for another online magazine. As a rule, the opposite is the case with such effects, which is a good testimonial for Bose’s surround sound algorithm. I only find the names of the two immersive audio modes a little confusing. (The app obviously has a small translation problem, also jumps between German and English terms in the instructions). But the head tracking works so well in the “unmoved” mode that the music even moves behind your head. This led me to conduct impressive sound experiments on my swivel office chair, because the remarkable capabilities of the Bose QuietComfort Ultra are far from exhausted with the maximum head rotation angle.
Fun with the bass
I find the result highly respectable. Many years ago, I had dealt extensively with the studies of Dr. Günther Theile from IRT on spatial hearing with headphones and the AKG K1000 in a special version, which was based on experiments on the MIR space station. I once borrowed a Neumann artificial head from the editorial department of my magazine at the time to make 3D recordings at home with my surround system. So I know how difficult it is to place a phantom sound source with headphones behind your back. And Bose achieves the feat of spatial reproduction even with normal stereo recordings. Chapeau!
During the listening test, fast head movements sometimes resulted in slightly delayed tracking effects. And sometimes the solo voice, which should actually come from the front and center, remained at an angle behind your head when you were already looking forward again. But I’ve never heard it better. There is still some room for improvement for any Mega Ultra MKII versions of the Bluetooth in-ears. But what Bose has created with the QuietComfort Ultra Earbuds in terms of immersive audio is great cinema and sometimes gives you goosebumps with the right music.
The basic 3D or spatial audio effect, as some call it, can be imagined as follows: The solo voice in the middle of the stage gains in contour and size, seemingly coming a little higher up and from further forward. At the same time, all the sound bodies seem much more three-dimensional. The head tracking even reacted to whether I moved my head up or down.
Basses are simply the “bassiest”
Tonally, Bose achieved a rich, impressive tuning. The bass sounds powerful, impressing with kick and contour at the same time. Only very few in-ears can achieve this quality and quantity. There will certainly be some for whom the bass may seem a little too dominant. But there is research, including that of old master Sean Olive, which states that a small boost in the bass is generally good for headphones in order to compensate for the psychoacoustic effect of the lack of structure-borne sound on the diaphragm.
Who hip-hop. If you like pop or rock, you will certainly enjoy the rich, deep punch, just like we do. No matter whether we use the Bose QuietComfort Ultra Earbuds with electronic beats like on “Empire State Of Mind” by Jay Z feat. Alicia Keys or acoustic drums like on an old Genesis live recording with Peter Gabriel on “Back In NYC”: the sound was thrilling with its kick and powerful, precise punch right down to the lowest octaves. The dynamic range is also impressive. It simply turns you on, has a drive that carries you away.
The mids and highs are likely to leave less enthusiasm than the low tones. Bose has managed to achieve a harmonious sound balance with the QuietComfort Ultra. But after the first impression, which is characterized above all by the plump, precise bass and the full-bodied fundamental range, sooner or later you come across small problem areas.
The QuietComfort Ultra is perfect for contemporary Music
We have heard more neutral and nuanced female voices in particular, but also high male voices, especially in this price range. Without the immersive audio effect, they appear somewhat undifferentiated and slightly overcast. With the 3D sound effect, they gain to the same extent as the transparency of the overall sound image, but then appear slightly artificial and even slightly whiny at times. The somewhat restrained treble reproduction may not generate enthusiasm among audiophiles who want to catch the very last nuances in special recordings of classical music or jazz.
But the fun-focused warm tuning also has something pleasant about it if you want to listen stress-free for a long time. Let’s put it this way: The tuning is aimed less at high-end users or testers who break down the playback into its elementary particles during the evaluation than at those who expect to simply turn on their 350-euro in-ears with their favorite tracks from Spotify, Qobuz or Deezer. And that they can experience music on the move within the physical possibilities as they know it from their hi-fi speakers or Sonos systems.
Conclusion and alternatives to the Bose QuietComfort Ultra Earbuds
The Bose QuietComfort Ultra Earbuds are among the most expensive TWS and therefore have to compete with the crème de la crème of audiophile manufacturers.
The slightly more expensive Bowers & Wilkins PI7S2 offers more transparency and high-frequency resolution combined with a more natural articulation of voices and a clever streaming concept. The Sennheiser Momentum True Wireless 3 remains the benchmark for naturalness and transparency. The Sony WF-1000XM5 sounds finer in the mids and especially in the highs than the QC Ultra. It also satisfies the desire for immersive sound. But its Sony 360 Reality Audio requires music tracks in the appropriate format, such as a premium subscription to Spotify or Tidal, while the Bose’s algorithm also makes normal stereo recordings sound spatial via upmix. And the WF-1000XM5 has no head tracking to fix the imaginary stage firmly in front of the listener even when turning.
What speaks in favor of the Bose, regardless of the comparison with the competition, is its kicky, deep bass in rock and pop music as well as its spatial sound, which leads to a very natural listening experience despite minor tonal weaknesses in high vocal ranges and the increased background noise. The successful head tracking does the rest, so that you can forget to listen to headphones at certain moments.
One more Thing: Bose QC Ultra Earbuds vs QuietComfort II
Finally, I would like to address the obvious question of how the new QuietComfort Ultra compares to its direct predecessor, the QC II. With a runtime of 24 hours and three recharges in the case, everything remains the same. The recently supported additional aptX codecs and aptX Lossless are only relevant for Android users. For iPhone and iPad users whose AAC codec was already supported by the predecessor, nothing will change in this respect. What represents a really big leap forward for all user groups is the impressive 3D sound with head tracking, which in practice brings the listening experience much closer to hi-fi speakers than is usual with headphones, despite the occasional small glitch during fast movements.
Technical specifications Bose QuietComfort Ultra Earbuds
- Manufacturer’s suggested retail price: 350 Euro
- Type: In-Ear
- Transducer principle: Dynamic
- Weight: 6.2 g each, case 60 g
- Special features: active noise-canceling, 6 h battery life, 24 with recharging in the case, water-repellent according to IPX4, app control,
- More at: bose.com