AlphaTheta HDJ-F9 – Wireless On-Ear DJ Monitoring

The HDJ-F9 is a closed on-ear DJ headphone for working DJs who want to cue without a cable tying them to the mixer. SonicLink, AlphaTheta's low-latency wireless link, keeps the delay at around 9 ms, so beatmatching by ear still feels natural. At Soundium it sits as the lighter, more compact entry into the HDJ-F wireless family.

Key Features

• SonicLink wireless: About 9 ms latency and up to 15 m range for real-time cueing in the booth.
• Touch pairing: Touch the headphones to a DJM-V5 or the HP-TX01 transmitter to connect instantly.
• New 40 mm driver: PEEK-PU-PEEK composite diaphragm with a bass-reflex chamber for punchy, defined kicks.
• Strong isolation: Closed on-ear design that blocks booth noise, so you can monitor at lower volume.
• Built for one-ear cueing: Swivel hangers, a flexible silicone headband and a die-cast aluminium slider.
• Bluetooth 5.3 multipoint: Connects to two devices with Google Fast Pair and Windows Swift Pair for everyday listening.

Customer Benefits

Wireless DJ headphones are only useful if the timing holds up, and SonicLink is built for exactly that. You can step away from the decks, hand over between sets or move around a crowded booth while the cue signal stays tight. When the gig ends, switch to Bluetooth for up to 25 hours of listening, and if the battery runs out, plug in the included coiled cable and keep going. The bayonet locking connector stops the cable from pulling loose mid-set, and the HEADPHONES CONNECT app lets you adjust the status LED and find misplaced headphones.

Quick Specs

• Type: Closed, dynamic, on-ear
• Driver: 40 mm PEEK-PU-PEEK composite
• Frequency response: 5 – 30,000 Hz
• Impedance: 32 Ω
• Sensitivity: 106 dB
• Battery life: up to 9 h (SonicLink) / up to 25 h (Bluetooth), status LED off
• Charging: about 2.5 h via USB-C; a 30-minute charge gives about 2.5 h of SonicLink use
• Wireless: SonicLink (2.4 GHz, about 15 m); Bluetooth 5.3 (SBC, AAC, about 10 m)
• Weight: 285 g

In the Box

• AlphaTheta HDJ-F9 headphones
• 1.2 m coiled cable with L-shaped plug (about 3.0 m extended)
• 6.3 mm screw-on stereo adapter
• USB Type-C to Type-C charging cable (0.5 m)
• Carrying pouch
• Quick Start Guide

Ideal For

• Club and mobile DJs who want cable-free cueing
• DJM-V5 owners using SonicLink touch pairing
• DJs who want one pair for the booth and for daily listening

Compatibility

SonicLink works with the DJM-V5 (latest firmware) and other supported AlphaTheta units, or with any mixer through the HP-TX01 transmitter. It also works over Bluetooth or with the included 3.5 mm cable.

Pros and Cons

✅ Pros:

• Low-latency wireless cueing that stays in time
• Light 285 g on-ear build with strong isolation
• Works wired, over SonicLink or over Bluetooth

⚠️ Cons:

• Mixers without SonicLink need the HP-TX01 transmitter (sold separately)
• No active noise cancelling, unlike the HDJ-F10

If you want the freedom of wireless cueing without stepping up to a flagship over-ear, the HDJ-F9 is the practical pick in the HDJ-F range. Pair it with the HP-TX01 transmitter for any mixer, and find both at Soundium.