General Information
The HD 550 is a compelling ultra-light headphone for audiophiles that want neutral and uncolored sound for reference listening. With its naturally balanced tuning and engaging bass extension, it offers a transparent window into your music and games.
At the core of the HD 550 is a finely tuned 38mm dynamic driver engineered for precision. Its wide frequency range—6 Hz to 39.5 kHz—captures everything from deep, textured lows to sparkling highs with clarity and control. The open-back design goes a step further with angled transducers that pull the listener into its panoramic soundstage. A new voice coil and diaphragm design offer a sublime listening experience with some of the most lauded DNA from stablemates HD 560S and HD 505.
The HD 550 features a familiar and beloved chassis, optimized in 2025 for a more polite, reduced clamping force. At just 237 grams, it’s built for long, immersive sessions. The headband provides a secure yet gentle hold, lined with soft synthetic leather for added comfort. Plush velour ear cushions ensure breathability and a pleasant feel, inviting you to lose yourself in the music.
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The headphones use a single-sided detachable 1.8-meter / ~6 foot cable, terminating in a 3.5mm jack. It includes a 6.3mm screw-on adapter, offering versatility across different audio equipment. The left-sided cable entry minimizes tangling, and the detachable design allows for easy replacement or upgrading of the cable including balanced and in-line mic options.
Features:
- 38mm (diaphragm) dynamic transducers, aluminum voice coil
- Coupling: Over-ear (circumaural), velour pads
- Acoustic principle: Open-back (ventilated)
- Frequency response: 6 - 39,500 Hz
- Impedance: 150 Ω
- SPL: 106 dB (1 kHz / 1 Vrms)
- Total Harmonic Distortion: <0.2% @ 1 kHz, 90 dB
- Headband: Adjustable, synthetic padded leather
- Weight: 237g (without cable)
- Cable: 1.8m (~6ft) with 3.5mm (⅛-inch) stereo plug; includes 3.5mm to 6.3mm (¼-inch) screw-on adapter; single-sided entry
- Cinched storage pouch for low-profile storage and protection from dust
- Wired for balanced operation; balanced cable sold separately (part number 700403)
- Also compatible with in-line mic cable (cable sold separately, part number 572281)
Spare parts page (coming soon)
Official announcement
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A note about naming: Like many audio brands, we use an alphanumeric system for many of our products. After 80+ years in business, we have no doubt amassed an enormous catalog of product names....some of the rules we have established have been bent as the markets and products evolve. As of this writing (3/14/2025), we're simplifying the names so that it becomes a bit easier to classify our products. While not perfect (and not entirely retroactive) our next few releases are a great demonstration of the new naming methodology.
The first letters classify the headphone at the widest part of the funnel: "HD" stands for Headphone, Dynamic, as it always has. IE is an In-Ear (dynamic), HE is Headphone Electrostatic, etc. This remains unchanged.
The next number (in this instance, "5") places the headphone in a performance series: HD 500, 600, or 800..again, unchanged.
The numbers after that is where we are going to tighten things up.
x20 will be reserved for closed-back models (example: HD 820, HD 620S) x50 and x00 will lean towards neutral tuning (example: HD 800S) x60 will lean towards a warmer tuning (example: HD 660S2) xx5 will, in most cases, indicate a retailer limited release in your market (example: HD 505)Our back catalog is full of exceptions and nuances, so feel free to ask any questions if you have them.
