Audio Technica’s ATHLS400iS inear headphones deliver terrific sound quality on the strength of an innovative quad Balance Armature (BA) Driver.

This is the top of the line of five sets of earphones in the Live Sound series.

The BA Driver is actually four drivers in one – two low-frequency drivers with a mid-frequency and a high-frequency driver – all within a single earpiece.

Designed to deliver each frequency to the ear with maximum clarity, their combined output is exceptionally detailed, dynamic and well balanced.

The driver housings of titanium and clear Tritan copolymer resin (for a nice, distinctive, seethrough touch) reduce unwanted resonance.

Acoustic sound pipes are enclosed within eartip posts that “guide” the music from drivers to ears with improved high-frequency response.

The eartip posts, angled for a comfortable, sound-isolating fit, come in four sizes – XS, S, M and L – so you can select to best fit.

The LS400iS boasts high sensitivity of 105dB, frequency response of 15 to 20,000Hz and 20 ohms’ impedance.

You get a detachable 1.2-metre cable with A2DC (Audio Designed Detachable Coaxial) connectors at the headphones for exceptional durability and audio performance.

The cable is equipped with an inline microphone and controller for handling phone calls as well as music and video playback on compatible devices. The flexible memory cable loops around the ears for a custom fit.

I tested the earphones with a Sony Xperia XZs phone and got great music reproduction with clarity, powerful bass and fine details. These things are fantastic for listening to rock music.

They’re also very comfortable to wear. The eartips completely sealed out external noise so I could enjoy my music without disturbances or distractions.

The inear remote can be used to answer a call or hang up as well as for controlling the music playback. While playing music, you press once to pause and again to resume. Press twice to skip to the next track and three times to return to the previous track.

RTB Technology sells the ATHLS400iS for Bt19,900.

KEY SPECS

– Frequency response: 15 to 20,000Hz

– Maximum input power: 3mW

– Sensitivity: 105dB/mW

– Impedance: 20 ohms

– Weight:  12 grams without cable

– Cable: Detachable 1.2m with A2DC connectors

– Connector: 3.5mm goldplated stereo miniplug, Lshaped

– Accessories included: Silicone eartips (XS/S/M/L), hard carrying case