Sennheiser HD 599 SE – Open-back Headphones for Home Use

The Sennheiser HD 599 SE is built around an open-back design. It was returned because the previous owner switched to a closed-back model. Checked, visible sign of use on the headband. That defines its character: you get a spacious, natural soundstage, but ambient noise remains audible. This is a headphone you connect to your stereo system or laptop, not for on the go. Weighing 250 grams and with large, removable ear cushions, it is designed for longer listening sessions. The 3-metre cable – detachable – gives you freedom of movement.

The open-back design is the core. Air can move freely, resulting in a less confined sound. The specifications support that: a frequency range of 6 Hz to 39,500 Hz. That is well beyond what the human ear can perceive, theoretically offering room for nuance. The bass is described as having 'deep contours'. But open-back also means: no isolation. Sound leaks out and ambient noise comes in. This headphone requires a quiet environment.

Under the hood

• Acoustic design: Open – for a spacious soundstage, no sound isolation.
• Frequency response: 6 Hz – 39,500 Hz – wider than the audible spectrum.
• Connectivity: 3.5 mm jack – wired, no Bluetooth.
• Cable length: 3 m – with detachable cable and 6.3 mm plug.
• Microphone: In the earcup – for speech, no external boom.
• Weight: 250 g – excluding cable.

Sennheiser prioritised wearing comfort for long periods. The headband is wide and padded. The ear cushions are large and soft, and they are removable – making maintenance easier. The whole thing is finished in black with a contemporary, not too flashy design. The earcups do not swivel and the headphone does not fold. This is a robust, fixed design for home use.

The HD 599 SE is designed to connect to home entertainment equipment. The included 6.3 mm plug is standard for amplifiers and receivers. For a laptop or phone, you use the adapter to 3.5 mm or the separate shorter cable. Note: many new smartphones no longer have a headphone jack. A separate adapter is then needed. Because it is not wireless and has no battery, you are always connected via the cable. That is a deliberate choice for audio purity, but it limits freedom of movement. The passive noise cancelling – actually just the damping of the ear cushions – is minimal due to the open design.

The packaging measures 318 x 154 x 96 mm and contains, besides the headphone, two cables and an adapter.