The $349 HDJ-F9 adds AlphaTheta’s low-latency SonicLink wireless system to a lighter on-ear design, though most mixers still require a separate transmitter.
AlphaTheta has expanded its SonicLink line with the HDJ-F9, a professional on-ear wireless DJ headphone priced at $349. The model sits below the over-ear HDJ-F10 and is pitched as a more compact, lighter alternative for DJs who want cable-free monitoring without moving away from AlphaTheta’s low-latency wireless system. According to AlphaTheta, the headphones are designed to combine a minimalist look with event-friendly customisation through its HEADPHONES CONNECT app.
The core of the product is SonicLink, AlphaTheta’s proprietary 2.4GHz wireless link rather than standard Bluetooth. The company says the connection is intended for ultra-low-latency monitoring, with a claimed delay of 9 milliseconds, a figure that places it in the range required for beatmatching and scratching rather than casual listening. DJ TechTools noted that the HDJ-F9 weighs 285 grams, making it notably lighter than the HDJ-F10, and that the on-ear format uses the familiar DJ-style layout with swivel hangers for one-ear cueing and shoulder rest.
AlphaTheta has also added a more direct pairing method. The HDJ-F9 can connect by tapping the headphones against a compatible mixer, starting with the DJM-V5 after a firmware update. The DJM-V5, which launched as AlphaTheta’s first mixer with a built-in SonicLink transmitter, is currently the only device the company has officially named for this feature. For most users, however, the headphones will still require the separate HP-TX01 transmitter, which plugs into a mixer’s headphone output. That extra unit means the wireless setup costs more than the headset alone and adds another device that must be charged and carried to gigs.
Battery life is rated at seven hours with SonicLink and the status light enabled, or nine hours with the light switched off. If the battery runs down, the headphones can fall back to the included coiled locking cable. AlphaTheta does not list active noise cancelling on the HDJ-F9 specification sheet, unlike the HDJ-F10, and third-party coverage also highlights features such as Bluetooth for casual listening, app-controlled LED colour and brightness, and 40mm drivers tuned for clear, bass-forward monitoring in loud booths. The company says availability is set for late October, although at least one retailer has already listed the headphones as in stock.
Disclaimer: This content is intended for informational purposes only. Readers are advised to exercise their own judgement, conduct due diligence, or consult a qualified expert before acting on any information provided.
