Behringer SD251-CK PRO Professional In-Ear Monitor Headphones (Black)

With a 107 dB SPL sensitivity and 16-ohm impedance, the SD251-CK PRO delivers detailed, high-output sound from any source, while its single dynamic micro-driver reproduces a 20 Hz – 20 kHz frequency range with punchy bass and crisp highs. Built for the stage and the street, these in-ear monitors combine a detachable OFC cable, 25 dB passive isolation, and a low-profile over-ear design that stays put during energetic performances.

Overview

The Behringer SD251-CK PRO is a professional in-ear monitor system engineered for musicians, audio engineers, and discerning listeners who demand accuracy and durability. The earphones feature a single dynamic micro-driver that delivers a balanced, full-range sound signature, making them suitable for monitoring live mixes, tracking in the studio, or enjoying music on the go. The black, ergonomic low-profile housing sits discreetly in the ear, while the over-ear cable routing reduces microphonics and keeps the cable out of the way.

What stands out

• Detachable oxygen-free copper cable with standard 2-pin connectors for easy replacement or upgrade.
• Gold-plated 3.5 mm TRS jack plus a 6.3 mm adapter for compatibility with pro audio gear.
• Up to 25 dB of passive noise isolation to block stage volume and ambient noise.
• Includes six pairs of ear tips (silicone and foam in S/M/L) for a custom, secure fit.
• Zippered carry case protects the monitors during transport and storage.

Technical details

• Driver type: Single dynamic micro-driver
• Frequency response: 20 Hz – 20 kHz
• Impedance: 16 ohms
• Sensitivity: 107 dB SPL @ 1 kHz (1 mW)
• Cable: Detachable, oxygen-free copper (OFC), 1.6 m length
• IEM connector: 2-pin (0.78 mm standard)
• Audio connector: 3.5 mm TRS stereo jack, gold-plated
• Adapter included: 6.3 mm (1/4") TRS
• Noise isolation: Up to 25 dB (passive)
• Design: Over-ear cable routing, ergonomic low-profile
• Color: Black
• Included ear tips: Silicone (S/M/L), foam (S/M/L)
• Included case: Zippered carry case

Our verdict

The SD251-CK PRO punches well above its class, delivering pro-grade sound and build quality at a price that makes it accessible to any performer. The detachable cable and generous tip selection ensure a personalized fit, while the robust isolation lets you focus on the music. A smart investment for reliable in-ear monitoring.