The sE Electronics KLS 150 is a professional closed-back, over-ear headphone designed for studio recording, monitoring, mixing and live sound applications. Featuring custom 40 mm dynamic drivers, it delivers a wide frequency response of 12 Hz to 28 kHz for detailed audio reproduction across the frequency spectrum. Its innovative adjustable acoustic bass control allows users to tailor the low-frequency response to their listening preferences and monitoring requirements. The closed-back, dual-shell earcup design provides effective isolation, helping minimise external noise and headphone bleed during recording sessions. Built for professional reliability and comfort, the KLS 150 features memory-foam earpads, swivelling earcups, a detachable 3 m locking cable and a robust construction incorporating reinforced components and spring steel. With a 39-ohm impedance, it is suitable for use with a variety of studio and portable audio devices. Supplied with a 6.35 mm adapter, USB-C adapter, protective pouch and earcup-cover opening tool, the sE Electronics KLS 150 is a versatile monitoring solution for musicians, producers, engineers and audio professionals. Key features Adjustable bass response: Mechanical acoustic adjustment on the earcups; no batteries or DSP required. Isolation: Dual-shell earcup design helps reduce external noise and headphone bleed. Durability: Glass-fibre-reinforced components and corrosion-resistant spring steel. Monitoring flexibility: 90° swivelling earcups for one-ear monitoring. Replaceable cable: Locking connector helps prevent accidental disconnection.