A/550
A New Chapter in The Sound of Koss
The Koss A/550 Open-Back Headphone represents the pinnacle of acoustic engineering and design.
A/550 is meticulously crafted from premium materials including stainless steel, aluminum, ultra-soft velour, and precision-stitched vegan leather. Designed and engineered in Milwaukee, WI, A/550 has been developed, refined, and tested to create a headphone that doesn’t just reproduce audio, but transports listeners directly into the heart of the performance.
From A/250 to A/550
Legendary Design. Legendary Sound.
The Koss Auditor line was a series of high-fidelity headphones released in the 1990s, designed to bridge the gap between professional studio monitoring and high-end home audio. The series was characterized by a focus on transparency, accurate imaging, and unique ear-cup design that deviated from the traditional circular or rectangular shapes of the time.
The A/250 is often cited as the "Holy Grail" of Koss dynamic headphones, and was wildly celebrated for its exceptionally balanced sound signature that delivered remarkable clarity, precision, and depth many listeners felt rivaled far more expensive headphones.
A/550 builds on the acoustic legacy of the A/250, delivering an open-back listening experience that reveals every nuance and detail in your favorite music that is unmatched in its class.
A Sonic Symphony
Hearing is Believing
The Koss A/550 Open-Back Headphone is the result of decades of dedication to sound innovation. Every detail has been considered to deliver unparalleled audio performance, durability, and comfort.
Listeners can expect an extraordinary experience where nuance, detail, and emotion are revealed exactly as the artist intended.
12-22,000 Hz
Ultra-Wide Frequency Response
At the core of the A/550 lies its Koss engineered 54 ohm Koss RLX44 dynamic driver system. Each driver integrates a multilayer polycarbonate diaphragm for exceptional rigidity and control, a precision-machined Neodymium magnet for superior efficiency and responsiveness, and an ultra-lightweight Copper-Clad Aluminum voice coil for rapid transient response.
All of this is housed within a reinforced 44 mm resin frame, carefully designed to reduce resonance and preserve sonic purity. The result is an open-back headphone capable of reproducing breathtaking, high-fidelity audio across a broad frequency range of 12 Hz to 22,000 Hz.
From the deepest, resonant lows to the most delicate highs, every note is rendered with astonishing clarity, balance, and depth. Subtle details emerge with lifelike realism, mids are warm and natural, and highs remain airy and precise without ever becoming harsh.
Light as Air. Strong as Steel.
Just 287 Grams
The brilliance of the A/550 doesn’t stop with its sound, because it looks every bit as impressive. Built from an uncompromising selection of premium materials, A/550 achieves a perfect balance of form and function.
Every material was chosen not only for its tactile quality, but also for its ability to enhance the listening experience through comfort, fit, and durability. Stainless steel provides enduring strength and resilience, while lightweight aluminum ensures structural integrity without unnecessary bulk.
Magnetizing Comfort
Designed for Extended Listening Sessions
Magnetically attached ear cushions wrapped in ultra-soft velour provide exceptional all-day comfort, gently conforming to the natural shape of your ears with its 'D-Profile' design. Precision-stitched vegan leather accents add a refined, timeless touch, blending durability with elegance in every detail.
Combined with an auto-adjusting head sling with a breathable fabric band, A/550 ensures a secure yet feather-light fit, promoting airflow and reducing pressure for hours of uninterrupted listening comfort.
Together, these elements create a headphone designed not only for superior sound, but also for effortless wear during the longest listening sessions.
#TheOriginal
60 Years of Sound Innovation
In 1958 John C. Koss changed the way we all listen to music when he invented the world's first SP/3 Stereophone, and for over 60 years, Koss has led the way in headphone design and innovation.
The Koss A/550 Open-Back Headphone continues this legacy and represents the pinnacle of acoustic engineering, delivering unmatched performance, comfort and design.
This is the next chapter in The Sound of Koss, this is A/550.
