Bluetooth’s new HDT mode is nearly four times faster and opens the way to lossless audio

Lossless music over Bluetooth could soon stop depending on whether your phone and headphones happen to share the same codec. The Bluetooth Special Interest Group has adopted High Data Throughput (HDT), a new mode for Bluetooth LE, and says its first flagship job will be standardized lossless and high-resolution audio, expected in 2027.

The key number is 7.5 Mbps. That is the new top bit rate, nearly four times what the Bluetooth LE 2M PHY can carry today, and it comes from a new physical layer with sturdier modulation that packs more data into the same link. Moving data faster also lets the radio drop into low-power states sooner, so the SIG promises better battery efficiency alongside the speed.

Right now, hi-res wireless listening is a patchwork. The source and the headphones must support the same proprietary codec, such as Qualcomm’s aptX family or Sony’s LDAC, and iPhones support neither, What Hi-Fi? notes. The magazine counts at least 11 wireless codecs on the market, so a single option built into the standard would be a relief for buyers.

Audio is not the only target. The SIG says HDT will also carry multi-channel surround and spatial audio, and pitches it for smart glasses that hand off data for AI processing and smart home gadgets that install firmware updates with barely any downtime. Nordic Semiconductor’s Øyvind Strøm gave the most concrete example:

Imagine a smartwatch that syncs hours’ worth of sensor-rich training data to your phone in seconds.

Øyvind Strøm, executive vice president, Nordic Semiconductor

What the SIG has not explained yet is how quickly HDT will reach shops: buyers will need both a phone and headphones built for it, and the audio standard itself is not expected until 2027.

Reported by Bluetooth SIG, What Hi-Fi?. Compiled with AI tools.