EarFun K4

Headband Adjustment & Fit

According to the manufacturer, the EarFun K4 is suitable for children aged 3 and up, as well as for teens and adults. The adjustable headband indeed accommodates a wide range of head sizes. However, the over-ear cups appear quite large for toddlers and will likely fit better from primary school age onwards. The K4 is heavier and larger than the EarFun K2, weighing in at 214 grams.

As an over-ear model, the K4 doesn’t offer strong passive noise isolation, making it less effective in loud environments. On the flip side, it allows good airflow and avoids overheating. The fit is more relaxed than tight, which means minimal pressure even during extended wear. The foldable design is practical for transport and storage.

Battery Life of the EarFun K4

Despite its compact format, the EarFun K4 impresses with up to 78 hours of playback (with lighting off). A 10-minute fast charge via USB-C provides an additional seven hours of playtime. A full charge takes about 2 hours and 50 minutes.

The 3.5 mm audio input on the right earcup also allows wired listening – ideal for compatibility with devices like the Toniebox or tiptoi pen. A mini-jack cable is included alongside the USB-C to USB-A charging cable.

Controls

The EarFun K4 features a power slider and three physical buttons for controlling playback and volume. You can skip tracks, answer/end calls, and adjust volume. A fourth button toggles lighting modes.

The Bluetooth connection is notably stable. Outdoors, the range extends to about 30 metres with clear line of sight; indoors, the signal easily passes through multiple rooms and even between floors without dropouts.

How Good Is the Volume Limiter?

To protect sensitive young ears, the EarFun K4 offers a three-level volume limiter:

• 74 dB for quiet environments (recommended for younger children)
• 85 dB for everyday listening
• 94 dB for noisy settings like travel

Switching between levels is done by pressing the volume up and down buttons simultaneously, with voice confirmation from a child-like voice. However, there’s no external indication of the active level – so regular checks are advisable.

Important: The volume limiter only works in wireless mode. When using the audio cable, there’s no limiter – volume can reach up to 94 dB. Careful manual volume control is essential in passive mode.

Call Quality – Voice Transmission

Call quality is a weak point. Voices sound muffled and unclear, requiring focus from the listener. While the HD mic system does reduce wind noise, especially outdoors, the overall speech transmission lacks clarity. In noisy environments, the speaker’s voice is prioritised, which helps, but the quality remains average.

Glowing Stars

There are five LED lighting modes for the star design:

• Three static colours
• One colour-changing mode
• One blinking mode

The lighting is nicely executed – subtle rather than glaring, with a warm glow that enhances the headphone’s appeal without being distracting.

Sound Performance

The EarFun K4 uses 40 mm dynamic drivers to deliver a full, warm sound with a gentle tonal balance. The bass and mids are present and punchy, while the treble is more subdued – a child-friendly tuning, considering children’s heightened sensitivity to high frequencies.

Despite its warmth, the midrange remains clean and clear, which benefits voice reproduction. Dialogue sounds lively, easy to understand, and pleasantly warm. Even shrill characters or voices (like Pumuckl) don’t become annoying, as sibilance is rendered softly. Multi-character dialogue is clearly distinguished, which is remarkable for headphones in this price range.

Conclusion

The EarFun K4 offer excellent value for money. They shine with extremely long battery life, child-friendly sound tuning with good voice clarity, and well-designed lighting features. While the external indication of volume limiter settings could be improved and call quality is not the best, these headphones remain a great choice for kids and families.