Wireless earbuds are often not the most exciting products to test. The product is actually almost fully developed and as a manufacturer you no longer belong if you have not also launched wireless earbuds. As a consumer you can no longer see the wood for the trees and it is often difficult for manufacturers to really distinguish themselves. However, Anker is doing something new this time with the Anker Soundcore Liberty 4. These wireless earbuds are combined with a heart rate sensor. Is it actually useful or is it just a gimmick? The new earplugs from Anker (also known from Eufy’s smart home products ) have a suggested retail price of 149 euros.

Earbuds have a lot to offer
Before we go into the heart rate sensor, let’s take a look at the earbuds themselves. What does this model have to offer? Well, quite a lot. The earphones are equipped with ACAA 3.0, an advanced acoustic system with two dynamic drivers supporting LDAC, a Bluetooth technology for high-resolution music. The Liberty 4 support 360 Spatial Audio for music and movie sound for spatial audio. The built-in gyroscope recognizes your head movements and ensures that the sound always surrounds you or comes from a certain direction. Via HeadID you can create your own personal sound profile and even measure your ear canal.
Adaptive Noise Canceling is also present. The ambient noise is continuously measured and the degree of noise canceling is automatically adjusted accordingly. You can operate the ears by squeezing the stems. A single charge lets you listen to music for nine hours and together with the charging case it is good for 28 hours of music. Charging can be done wirelessly and via USB-C. Finally, the heart rate, because your heart rate and stress level can be measured via the right earpiece. You can see this in the Soundcore app. You will also find an extensive equalizer for the music here. The Anker Soundcore Liberty 4 are very richly equipped earplugs and have a suggested retail price of 149 euros. You can choose from a white and a black variant. We will start with the white variant.

Comfortable and fantastic app
The Anker Soundcore Liberty 4 comes in a luxury box that you can open completely. The earphones have a stick design with a silicone cap on the end. You will also find other sizes in the box, so you will always be able to find something that fits comfortably in the ear. The charging case and a manual are also included. What is immediately noticeable about the earphones is that they really stay in the ears fantastically. Of course this is personal and also depends on the shape of your ears, but in all those years of testing wireless earphones, these are by far the most comfortable earphones for my ears. They are made of plastic, but are solidly built and otherwise look great. The charging case has a sliding lid. That seems a bit fragile, but has not caused any problems here.
We grab the Soundcore app (available for iOS and Android) and easily connect the Liberty 4 to the phone. The app is for the most part clear, but has a lot to offer. So much so that we sometimes lose the overview. You can test all kinds of things, such as the ambient sound, the ear canal or set HeadID for a personal sound profile. We have obediently gone through all the tests, but we do question the usefulness of some tests. The difference is sometimes difficult to hear.

You also have a fully working 8-band equalizer at your disposal. You choose from various presets or set this completely manually. The Adaptive Noise Canceling is a bit disappointing though. In theory, the noise canceling should adapt to the amount of ambient noise and should be more muffled if there is more noise around you. In practice, this difference is not really noticeable. The transparency mode works quite nicely, but voices sound really far away.
You can also operate the earphones on the sticks. Anker calls it ‘pinch control’, but beneath the surface are actually buttons that you can press. You can press once, twice or three times and perform a certain action. You can set this completely to your liking for both the left and right earpiece via the Soundcore app. Since this squeeze control actually just works with hidden buttons, the operation works fine. Very different from swiping and swiping with other brands. That never really works very well. We can be very satisfied with the battery. You have more than enough music with you to get through several days.
Heart rate sensor
A heart rate sensor in the earbuds. Is it a gimmick now? Are you going to use it? And does it work? A round of cycling and a lunch walk gave more clarity. I made a comparison with the heart rate sensor of the Garmin Forerunner 955, a smartwatch from Garmin that has a fairly accurate heart rate sensor. You can also just start a workout in the Soundcore app and that’s what we’re going to do. And afterwards it turned out in both cases that it corresponds quite accurately. The Liberty 4 sometimes deviates a bit, with a maximum of two heartbeats, compared to the Garmin Forerunner 955. That’s pretty neat.

The earplugs also measure stress via the HRV (Heart Rate Variability). This also seems to work quite nicely and corresponds to Garmin’s Forerunner 955. Incidentally, the Liberty 4 earphones do not only measure during a workout, but also while listening to music. The only question is, who is this suitable for? The fanatical athlete has a sports watch from Garmin, Polar, Coros or Suunto. They are often slightly more accurate in the measurements. The Liberty 4 provides fairly good insight into your heart rate and heart rate zones, but lacks all kinds of other tools for the avid athlete to really do something with it. For the other athletes, it’s fun to take a look at the heart rate measurements or to get just a little more insight into your workout, but it also offers too few functions and options to really base your workouts on. However, Anker has really put time and effort into the ‘Wellness section’ of the Soundcore app and that looks great. The heart rate and stress measurement is fun and ensures that these earbuds really offer something unique compared to the hundreds of other wireless earbuds on the market, but it’s not entirely clear to me who will actually use this. Fortunately, these earphones also have a lot to offer when it comes to music.

Time for music
Earbuds are generally inferior to good over-ear headphones, but Yamaha has already shown that wireless earbuds can also sound really good. We are dealing here with very richly equipped earplugs, so if the sound is also good, then we are really dealing with a winner here. Unfortunately, the earplugs do not quite live up to expectations. Let’s start with the good news. The Liberty 4 earphones have a good stereo reproduction with a wide soundstage. With other earphones this is often a problem and it sounds very narrow, or very far away. That is absolutely not the case here. The bass is well present without exaggerating and if you choose Spatial Audio, you also have various options for spatial audio. First of all, you can choose from music or film, but also from a self-chosen fixed point of view or that you are always surrounded by the sound. It works really well and it’s fun just trying out the different modes in the app and then walking around or moving your head. These aren’t bass monsters, but they don’t have to be. The bass sounds well balanced without overdoing it. You also hear plenty of detail, but the ears go a bit too far.

The problem is in the adjustment of the earpieces. They can sometimes sound a bit too shrill and that hurts the ears after a while. And that’s a shame, because that comes at the expense of comfort at a certain point. The ears then sound particularly shrill in the highs, as if the treble is not properly adjusted and is too aggressive. In fact, we could say that the earphones reproduce music too clearly. You really hear a lot of detail in the music, but they go too far in that. You can partially adjust this with the equalizer in the app, but you won’t be able to get rid of it completely. If the base is just not right, you can’t get rid of it completely by playing with all kinds of settings. You will not hear it with all types of music, but it ensures that it is not always pleasant to listen. It just doesn’t match. It is therefore a pity that the low and mids sound just fine, although we sometimes miss a bit of warmth. It all sounds a little too clinical, but not in a good way. It probably won’t even notice everyone, but for 149 euros we have to be a bit more critical than with wireless earphones of 50 euros. Incidentally, the Liberty earphones Soundcore are also known for the aggressive treble, which was also the case with version 3. Is this sound your thing? Then you will also enjoy the Liberty 4. For me, however, this sound is just not it. They are good earphones that unfortunately could have been adjusted just a bit better. It all sounds a little too clinical, but not in a good way. It probably won’t even notice everyone, but for 149 euros we have to be a bit more critical than with wireless earphones of 50 euros. Incidentally, the Liberty earphones Soundcore are also known for the aggressive treble, which was also the case with version 3. Is this sound your thing? Then you will also enjoy the Liberty 4. For me, however, this sound is just not it. They are good earphones that unfortunately could have been adjusted just a bit better. It all sounds a little too clinical, but not in a good way. It probably won’t even notice everyone, but for 149 euros we have to be a bit more critical than with wireless earphones of 50 euros. Incidentally, the Liberty earphones Soundcore are also known for the aggressive treble, which was also the case with version 3. Is this sound your thing? Then you will also enjoy the Liberty 4. For me, however, this sound is just not it. They are good earphones that unfortunately could have been adjusted just a bit better. Is this sound your thing? Then you will also enjoy the Liberty 4. For me, however, this sound is just not it. They are good earphones that unfortunately could have been adjusted just a bit better. Is this sound your thing? Then you will also enjoy the Liberty 4. For me, however, this sound is just not it. They are good earphones that unfortunately could have been adjusted just a bit better.

Conclusion
The Anker Soundcore Liberty 4 are richly equipped earplugs with a lot of functions. The Soundcore app gives you as a user many options to fully customize everything to your liking. For 149 euros you can of course also expect a lot and in terms of options these earphones live up to it. It is a pity that the sound just cannot keep up with the top models in this segment. Despite the wide sound image with excellent stereo reproduction and the adjustable equalizer, the sound with some music genres sounds too shrill and they are not fully adjusted. Since the sound profile is really well adjustable within the app, we hope that the manufacturer will be able to balance this better with a firmware update. It’s a pity that this base is actually not good, because the comfort of these earphones is really fantastic. They are really very comfortable in the ears. The heart rate sensor is a nice gimmick and works pretty well, but will you use it much? I do not think so.
Pros
- Very comfortable on the ears
- Lots of options
- Excellent Soundcore app
- Spatial Audio works well
- Wide sound reproduction
- Good battery life
Negatives
- Treble too aggressive
- ANC is a bit disappointing
- Heart rate sensor is a gimmick