{"product_id":"auribus-acoustics-sierra-aluminum-open-back-headphones","title":"Auribus Acoustics Sierra Aluminum Open Back Headphones","description":"\u003cp\u003e\u003cem\u003eNote: This product is made-to-order and ships within one week.\u003c\/em\u003e\u003c\/p\u003e\n\u003ch1\u003e\u003cstrong\u003eSierra Aluminum solid aluminum open-back headphones\u003c\/strong\u003e\u003c\/h1\u003e\n\u003cp\u003eThe Sierra Aluminum is an evolution of the Sierra Reference, built to mark five years of the Auribus project. It pairs a warmer, more controlled tuning with single-piece aluminum construction and a lightweight 400g frame. A 50mm dynamic driver, angled 3D baffle, and open acoustic design work together to deliver wide staging, natural timbre, and full-range extension.\u003c\/p\u003e\n\u003ch2\u003e\u003cstrong\u003eSolid aluminum construction with SLM finish\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eThe outer shell is formed using selective laser melting, a 3D metal printing process that produces a dense, durable aluminum structure. Each housing is hand ground and tumble polished, leaving a subtle raw texture unique to every unit. Beneath it sits a one-piece 3D printed enclosure that keeps resonance controlled while maintaining low weight for long listening sessions.\u003c\/p\u003e\n\u003ch2\u003e\u003cstrong\u003e3D baffle for spatial accuracy\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eThe internal geometry places the driver at an angle relative to the ear, helping sound arrive more naturally. An asymmetrical aperture shapes how air and sound move through the chamber, widening the perceived stage without losing positional accuracy. This design supports layered recordings, making placement and depth easier to follow.\u003c\/p\u003e\n\u003ch2\u003e\u003cstrong\u003e50mm dynamic driver with paper cone\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eThe Peerless paper cone driver emphasizes natural tone across the spectrum. Paper diaphragms are known for balanced stiffness and damping, which helps avoid harshness while preserving detail. Combined with the open acoustic structure, the result is a presentation that stays coherent from low bass through upper treble.\u003c\/p\u003e\n\u003ch2\u003e\u003cstrong\u003eLinear extension system for full-range response\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eAn updated version of the Linear Extension System manages airflow and damping to maintain consistent output across frequencies. The design supports extension from 20Hz to 20kHz, allowing both low-end weight and high-frequency detail to come through without abrupt roll-off. This is especially noticeable in recordings with wide dynamic range.\u003c\/p\u003e\n\u003ch2\u003e\u003cstrong\u003eAdjustable comfort for long sessions\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eThe frame allows adjustment of clamp force to suit different head shapes. At 0.88 lb (400g), the weight stays manageable for extended use. Dekoni hybrid leather and velour pads distribute pressure evenly while maintaining a stable seal. The floating headband design spreads load across the top of the head, reducing fatigue over time.\u003c\/p\u003e\n\u003ch2\u003e\u003cstrong\u003eAmplifier pairing for optimal performance\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eWith a 20-ohm impedance at 1kHz and moderate power demands, the Sierra Aluminum benefits from a dedicated amplifier. A unit capable of at least 280mW at 32 ohms with low output impedance helps maintain control over the driver and ensures consistent tonal balance at different listening levels.\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eProduct highlights\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eOpen-back over-ear headphone design\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003e50mm dynamic driver with paper cone diaphragm\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eSolid aluminum SLM-printed housings\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eAngled 3D baffle with asymmetrical aperture\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003e20Hz–20kHz frequency extension via Linear Extension System\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eAdjustable clamp force with floating headband\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eHybrid leather and velour ear pads by Dekoni\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eRecommended use with dedicated amplifier\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eSpecs\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eDriver type: 50mm dynamic driver\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eImpedance: 20 ohm at 1kHz\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eFrequency range: 20Hz–20kHz\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eWeight: 0.88 lb (400g) without cable\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eMaterials: aluminum, nylon, PETG\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eCable: 1.4 meter (4.6 ft) 3.5mm to 3.5mm cable\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eRecommended amplifier power: 280mW @ 32 ohm with \u0026lt;1 ohm output impedance\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eWhat’s included\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003ePadded carry case\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003e1.4 meter (4.6 ft) dual 3.5mm cable with 3.5mm or 4.4mm termination\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eDekoni Elite hybrid leather and velour ear pads\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eStereo wired headphones\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Auribus Acoustics","offers":[{"title":"Default Title","offer_id":47484254585068,"sku":"APS-1299-1","price":1600.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0225\/2721\/3642\/files\/apos-audio-auribus-acoustics-headphone-auribus-acoustics-sierra-aluminum-open-back-headphones-1231431874.jpg?v=1775683089","url":"https:\/\/apos.audio\/products\/auribus-acoustics-sierra-aluminum-open-back-headphones","provider":"Apos","version":"1.0","type":"link"}