In the S series, final has utilized two open-back dynamic drivers to enhance air throughput, allowing the S4000 to achieve a sense of airiness and extended musical detail. By arranging the drivers in a mirror image configuration, this design ensures that the drivers have consistent vibration points during operation, allowing their resonances to cancel each other out, resulting in improved stability and low distortion performance.

For the S4000, final has chosen its proprietary eight-strand silver-plated copper headphone cable, which effectively delivers smooth and clear mid-high frequencies. The soft cable material also helps prevent the stethoscope effect caused by friction between clothing and the headphone cable. Additionally, the S4000 feature matching colors on the 2Pin connectors and splitters, enhancing the cohesive look of the cable and headphones.

Benefiting from the properties of stainless steel, the S4000 delivers clear and bright mid-high frequency imaging. When playing pop, funk, or folk music, it enhances the representation of guitar and vocals.