Description
What the Liberty 4 Pro Is
The Soundcore Liberty 4 Pro sits at the top of Anker’s true wireless range and is built around two claims: an unusually elaborate noise cancelling sensor array, and a two-driver arrangement inside each earbud. It arrives with six sizes of ear tip, from XXS to XL, which is more than almost any competitor supplies and is a meaningful signal that Soundcore understands where cancellation performance actually comes from.
The product occupies the tier where flagship features from more expensive brands appear at a lower price, and the sensible way to judge it is against that context rather than against the absolute leaders. Buyers comparing options should look at the TOZO NC3 at a lower price point and at the wider earbud headphones category.
The Seven Sensor Cancellation System
Six sound sensors and one barometric pressure sensor is a lot of hardware for an earbud. The sound sensors sit inside and outside each bud, letting the system measure both the noise arriving at the shell and the noise that actually reaches the ear after the seal has done its work. That inner measurement is what allows a system to compensate for a poor fit rather than assuming a good one.
The barometric sensor is the more unusual inclusion. Ambient pressure changes alter how a sealed earbud behaves, which is why cancellation performance shifts during a flight takeoff or in a car with a window open. A system that measures pressure can adjust for it rather than producing the pressure sensation that many people find unpleasant. Soundcore states that the system adapts every 0.3 seconds, which is fast enough to track a changing environment rather than settling on an average.
Drivers and the Digital Crossover
Each bud contains a 10.5 mm driver handling bass and a separate titanium-coated tweeter for high frequencies, divided by a digital crossover rather than a passive analog one. Splitting the work between two drivers in a space this small is difficult, and the benefit is that neither driver has to compromise: the larger unit can be optimized for excursion and the tweeter for speed.
A digital crossover has a real advantage over a passive one here, since it can apply time alignment and phase correction that a passive network cannot, and it costs no space. Soundcore calls the overall architecture ACAA. The listing gives a frequency range of 20 Hz to 20,000 Hz, which as usual conveys nothing, and a sensitivity figure of 126 dB that is not credible as a sensitivity specification for an earbud.
The Case Touch Bar
The charging case carries a touch bar and a display, allowing noise cancellation levels to be adjusted with a swipe. This is worth thinking about rather than dismissing as a gimmick. Adjusting cancellation normally means unlocking a phone, opening an application and finding the right screen, which is enough friction that most people never do it and simply leave the setting where it was.
A physical control on an object already in the hand removes that friction entirely. The trade is that the case now has electronics, a screen and a battery drain of its own, and it becomes a more expensive item to lose or damage. The case measures roughly 64.6 by 61.7 by 29.6 millimetres, weighs 51 grams, and holds a 580 mAh cell.
Battery and Charging
Soundcore quotes up to 10 hours from the earbuds alone and up to 40 hours in total with the case, and describes charging as twice as fast as previous models thanks to a different battery chemistry, with 5 minutes giving 4 hours of playback. Ten hours from a bud containing two drivers and seven sensors is a strong figure, and the fast charge covers the situation where the buds were left out of the case overnight.
Charging time for the case is listed at 3 hours over USB-C. Calls are handled by six microphones with a noise reduction algorithm and a separate wind noise algorithm. As with all earbuds, that call processing improves the far end of the call rather than what the wearer hears; the cancellation system is what handles the wearer’s side. Buyers who want a longer single-charge runtime without a case should consider a neckband such as the Soundcore Life U2i from the same brand.
Highlights
- Seven sensors including a barometric one, which few competitors at any price include.
- Adaptive cancellation updating every 0.3 seconds per Soundcore.
- Two drivers per bud with a digital crossover between them.
- Six ear tip sizes from XXS to XL, which directly affects cancellation performance.
- Touch bar and display on the case for adjustment without a phone.
- 5 minute charge giving a stated 4 hours, with 40 hours total including the case.
Things To Consider
The most important gap in this listing is the water resistance rating. The specification block simply says “Waterproof” with no IP code anywhere, which is not a usable statement: IPX4 and IPX7 describe very different products, and a buyer planning to run in the rain has no way to know which applies. The sensitivity figure of 126 dB is also implausible, and the frequency response field holds a single number rather than a range. The listing additionally reports “Number of USB 2 Ports: 1”.
- No IP rating is published, only the word waterproof.
- The case is more expensive to replace given the screen and touch bar.
- No codec support is stated, which matters for anyone with a high resolution library.
- Bluetooth 5.3, current but not the newest available.
- The sensitivity specification is not credible as published.
- A 4.3 star average across roughly 1,368 ratings is solid rather than outstanding for a flagship.
Who Should Buy It and Who Should Skip It
The Liberty 4 Pro suits a frequent traveller or commuter who wants strong cancellation and is willing to spend below flagship prices to get most of the way there. The six ear tip sizes and the case-mounted control are the two features most likely to be appreciated after a month of ownership, and the two-driver arrangement gives the product a genuine technical argument rather than a marketing one.
Skip it if you need a published water resistance rating before buying, since the listing does not provide one. Skip it too if you already own capable cancelling earbuds, where the improvement will not justify the outlay, or if you prefer a design without a battery-powered case at all. Listeners who value sound quality above cancellation should compare a wired in-ear such as the Moondrop Space Travel alternative and the passive options nearby, and anyone who wants a full-size fit should look at the over-ear headphones category.
