Sennheiser Momentum True Wireless 4

Sennheiser Momentum True Wireless 4 :: $299.99 :: 7mm TrueResponse Transducer

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MTW4 features the same '7mm TrueResponse transducer' and 'Acoustic Back Volume' - that are also used in wired in-ear IE series, IE600 and IE900 - to deliver Sennheiser signature sound.

As a top-of-the-line flagship, they are powered by Qualcomm's latest Snapdragon Sound platform - the 'S5 Gen2' chipset, making them one of the very few to fully support Bluetooth 5.4 and the next generation wireless audio standard - 'LE Audio'.

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They allowed me to try it out few weeks earlier, by providing a sample unit for this review.
However, this review fully reflects the my honest opinion without anyone else's interference.

Btw, are you more familiar with Korean?
So am I, and If that's the case, I think you'd be better off reading my review written in Korean here.

This entire review was translated from Korean article using DeepL Translator with some refinement by myself.

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With carbon neutrality becoming the norm, the packaging has been streamlined, with a greater use of easily recyclable paper materials.

You can find several components inside the package.

- Sennheiser Momentum True Wireless 4 itself
- USB-A to C charging cable
- 3 pairs of silicone earwing sets (S/M/L, M Pre-installed)
- 4 pairs of silicone eartip sets (XS/S/M/L, S Pre-installed)
- User manuals



Unlike its predecessor, the eartips of the MTW4 don't have sponge dampers inside.
The damper has been removed in favor of a 'silicone filter' structure made from the same material as the eartips.

It should improve treble performance and make it easier to keep the eartips hygienic - one of the more welcome changes for me personally.

The earwings help to keep the earphones in your ears.
The smallest ear wing does not have bulge, so people with smaller ears can still wear them without problem.



On the outside, things are pretty much the same as last gen.

Except for a slightly less dense mesh at the tip of the nozzle, which, along with the eartip without the sponge damper, should improve treble reproduction.

I was a little disappointed that there's still no 'wind deflector' mesh to cover the microphone hole. This is something that pretty much every wireless earbud is trying to implement, as it can greatly reduce wind noise.




Fortunately, there are some improvements inside the unit.

MTW4 is equipped with Qualcomm's latest 2nd gen Snapdragon Sound platform - the 'S5 Gen2QCC5181' chipset.

It supports not only the popular aptX Adaptive codec, but also the aptX Lossless codec, which can transmit 16bit/44.1kHz sound sources accurately and losslessly, bit by bit.

While it's exciting to be able to listen to lossless music without wires, it's very difficult to reliably transmit such a large data of lossless music without wires with current Bluetooth technology. I think most people who have used existing high-resolution codecs will agree.

As a subset of the aptX Adaptive codec, the aptX Lossless codec is only automatically activated when certain conditions are met. If you have a device that supports aptX Lossless and it doesn't seem to be activating, check to see if the following conditions are met.

- Your device must support aptX Adaptive V2.2 or higher (Snapdragon 8 Gen1 or higher, support may vary by device)
- WiFi must be switched off or using the 5GHz band. (2.4GHz overlaps with Bluetooth)
- The music source you want to play must be 16bit/44.1kHz or 16bit/48kHz. (48kHz sound sources are downsampled to 44.1kHz)
- Your wireless connection strength must meet a certain level.

The last requirement is that the connection quality must be above a certain level for the lossless codec to be activated.

Fortunately, MTW4 doesn't just support the lossless codec, but Sennheiser claims to have worked with Qualcomm to redesign the antenna and use the latest communication technology to maximise connection stability.



You can see the difference by comparing photos of the inside of the housing.

The placement and area of the antennas is crucial for good connection reliability.
Unlike its predecessor, which used a single antenna, the MTW4 has two antennas, giving it a considerably larger overall coverage area.

With the significant improvements to the physical antenna design, I definitely noticed a significant improvement in the connection stability that many people who used the previous gen pointed out.

I rarely experienced any dropouts, even in a crowded subway during my commute and in a large cafe with a lot of communication equipment.

My only complaint was that when I started to move away from my multipoint-connected device, I would experience dropouts, even if the main device playing the sound was still close by.

Considering that other products with the Qualcomm 'S5 Gen1QCC5171' chipset, which also supports aptX Lossless, have the same issue, I suspect this is a bug shared by devices with the latest Qualcomm chipsets.

I have sent feedback to Sennheiser about this problem and a new firmware update went online few hours ago. I haven't tested it yet to see if it's fixed, but hopefully the firmware update will fix it.



The quest to enjoy lossless music without wire doesn't stop there.

We mentioned earlier that Sennheiser have not only revamped communication design but also applied the latest technology for stable lossless music listening.

The 'latest technology' we are referring to is 'LE Audio' - the next generation Bluetooth audio standard.

LE Audio is based on Bluetooth LE, an ultra-low power communication technology that is completely different from the Bluetooth Classic we've been used to. This allows it to consume much less power and operate much more efficiently given the same bandwidth.

By "more efficient," we mean lower latency while maintaining the same sound quality, or even better sound quality while maintaining the same connection reliability.

When you connect MTW4 to a Snapdragon 8 Gen2 or newer device, the aptX Adaptive (aptX Lossless) codec will most likely operate on the next-generation standard - 'LE Audio' - rather than the existing 'Bluetooth Classic'.

I don't have the latest Android device to test this, but it will allow more stable connection performance when playing lossless music.



I've described LE Audio as a new technology for stable, lossless music listening, but it's hard to say that's all it is - there are so many exciting new features.

One of the most iconic features is 'AURACAST'.

To put it simply, the 'Auracast' technology included in 'LE Audio' is something that breaks the frame of 'one-to-one' communication with a clearly defined 'receiver' and 'sender' - like a 'phone call'.

The 'Auracast' enables 'one-to-many' communication via Bluetooth, just like listening to the radio.



In fact, those who first led the development of 'LE Audio' was hearing aid companies.

The 'Auracast' technology is expected to be a perfect replacement for 'telecoil' devices that have not been widely used due to high installation costs. You'll be able to experience the importance of 'telecoils' in helping hearing impaired people with hearing aids to better hear voices in noisy and crowded places after watching the video above.

This doesn't mean that 'Auracast' is a technology that can only be used in limited areas - there are already smart TVs on the market that can connect three or more Bluetooth earphones simultaneously through 'Auracast' technology, so it has a lot of potential to bring new experiences to everyone in the future.



I've probably already spilled too much alien language, so let's answer the question "so what does it sound like".

The Momentum True Wireless 4 has the same 7mm TrueResponse transducer.

This, coupled with the 'Acoustic Back Volume' construction, achieved Sennheiser signature sound in wireless earphones by naturally regulating the airflow behind the drivers without the need for manipulating the signal with DSP.

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Measured with IEC 60318-4 (711) while maintaining 94dB@500hz.
The sample used for the measurement does not represent the characteristics of the entire product.

Following Measurements are available at dchpgall.squig.link - a collective 711 measurement database by Korean audiophile community users.



This is a basic sound measurement with active noise cancellation enabled.

Note that, as with its predecessor, it was impossible to align the resonance peak to 8kHz. I inserted them a little deeper than usual to bring the peak down to 7kHz.

In many ways, the signature Sennheiser sound from the wired IE series is quite visible on this unit as well. I would describe it as a right-skewed, slightly V-shaped sound.

Compared to the in-ear target, they have a slightly drop at sub-bass and a more body in the bass range, especially in the mid-bass, giving them a slightly smoother and fuller bass.

They do a great job of reproducing the resonance and texture of instruments without sounding muffled, and compared to their predecessors, I think this is a positive change that better represents the TrueResponse driver's charm.

Compared to previous Sennheiser earphones, the emphasis in the midrange is more towards the highs, which makes the sound more natural. and the way in which the TrueResponse driver's excellent treble extension is handled by gradually pushing the highs down until to 6kHz, while simultaneously giving a slight dip at 8kHz, ensures that the sound is not overly shouty.

Despite this, there is still a generous amount of upper treble, making for a clear highs.



MTW4's dedicated app - 'Sennheiser Smart Control' includes a 5-band equalizer with two features.

The 'Bass Boost' feature works with the five-band equalizer and, based on the sound you set, it gently adds ~3dB of bass from 500Hz onwards. It's shown that they are adjusting the overall sound as if you were putting on a preamp to avoid clipping and other adverse effects.

For the 'Podcast' feature, the sound is locked to a bass-reduced sound to make the voice band more audible, and the ability to modulate the sound, including the 5-band EQ, is disabled.

Take a look at the measurements above to see how each feature works!


In addition to this, there are 7 EQ presets pre-generated by Sennheiser using 5-band equalizer.

Each of the seven genre-specific EQs - 'Rock', 'Pop', 'Dance', 'Hip-Hop', 'Classical', 'Film' and 'Jazz' - has a different sound, and you can see how they compare to the Harman in-ear targets in the measurement image above.



Additionally, to give you an idea of how each of the five bands present in the dedicated app equaliser affect the sound, I've taken measurements with 6dB increments of each.

I hope this helps you on your journey to finding your own sound.



+ ANC

I've noticed that the sound changes slightly depending on whether Active Noise Cancellation is enabled or not, but the change is subtle enough that most people won't notice it.

There seems to be some disagreement on how well the noise cancelling performs, but I personally think it does a good job of blocking out noise, just not quite up to par with some of the best performing ones. It doesn't reduce the noise to the point of complete silence, but the range of noise cancelling is quite wide, and I found that it does a good job of blocking noise in the mid-to-high range.

According to Sennheiser, the MTW4's noise cancelling strength automatically adjusts to the level of ambient noise, but there's no way to lock the noise cancelling strength to the maximum, so I suspect there may be variations in noise isolation performance depending on the situation or wearing conditions.

Unfortunately, as I mentioned earlier, there is still no wind deflector mesh in this new model, but the algorithm does a good job of cancelling out wind noise, so I didn't feel the need to use the 'anti-wind mode' through the app. Personally, I think the 'anti-wind' feature is only necessary if you're running or in a extremely windy conditions.

+ Transparency Mode

The transparency mode, which lets you hear your surroundings, does a good job - it doesn't make you feel like you're not wearing earbuds, but it balances out a fairly wide range of ambient sounds and feels quite natural.

You can adjust the volume of the ambient sound through the app, but I personally felt that the default of 70% was a bit low, and turning the volume up to 100% definitely made the ambient sound more natural. but it will amplify the white noise and make it even more susceptible to wind noise.

I really wish they had a wind shield on it. You hear a lot of wind noise when you're in transparent mode.

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So far, we've taken a look at Sennheiser's latest flagship wireless earbuds - the Momentum True Wireless 4 (MTW4).

While the Sennheiser signature sound achieved with the 7mm TrueResponse transducers and Acoustic Back Volume in the previous iteration has been praised by many consumers and critics alike, the MTW4 introduces next-generation wireless technology to push the boundaries of wireless audio even further.

While 'lossless audio without wires' is still some time away from becoming the norm, the pace of progress suggests it may be closer than we think.

Of course, the sound of the aptX Adaptive codec, which can transmit up to 24bit/96kHz, is already compelling enough, but the fact that the redesign was aimed at "wireless, reliable, lossless music listening" and that other fundamentals such as "connection stability" were also addressed during the redesign process, I think there are some changes to convince even those who are still far away from lossless music to try it.

As with the previous MTW Series, the MTW4 is definitely recommended for those who want to experience Sennheiser's signature sound wirelessly, but it's even more recommended for those who want a glimpse into the future of 'LE Audio' and other next-generation audio technologies at the forefront of wireless technology.