Small and mighty: The Sennheiser BTD 700 can turn any device into an Auracaster
Sennheiser has released the BTD 700, another portable dongle that will turn computers and phones in Auracasters.
The tiny gadget is, Sennheiser says, a high-performance Bluetooth dongle that connects wireless headphones and earbuds. It uses aptX audio codecs and offers low-latency gaming possibilities, despite being less than an inch long and weighing 2.2g.
It comes with a single USB-C connection, and a type C to USB-A adapter so that it can be used in most computers, mobile phones and tablets.
Sennheiser says that while the BTD 700 is smaller than most flash drives, it packs a high-tech punch for streaming, gaming, and voice communications.
The use of aptX Lossless and aptX Adaptive codecs offers reliable, high-definition wireless audio with up to a 24-bit depth at 96 kHz.
And the company says that music lovers can explore their favourites on a deeper level using their aptX-enabled earbuds, headphones, and speakers by using the dongle to supercharge their digital audio source.
This includes headphones such as the Sennheiser MOMENTUM series, and select models from the ACCENTUM series are already equipped to support high-definition aptX codecs, with some in the range having Auracast built in.
Christian Ern, Sennheiser Senior Product Manager, says: “The BTD 700 makes high-performance wireless audio easy.
“This all-in-one unlocks sound quality that rivals wired connections – even adding cutting-edge Bluetooth functionality to PCs and mobile devices missing these newer audio features.”
Sennheiser promises plug and play with the BTD 700

Like the FlooGoo FMA120, the BTD 700 dongle uses Bluetooth 5.4, and can bypass the native audio output on practically any Android, iOS/iPad OS, Windows, and MacOS device as it becomes an Auracaster.
Once it is set up, operation is as easy as inserting a flash drive or USB stick into the machine that is outputting the audio. Users with an Auracast Assistant can then tune in to the Auracast signal.
Sennheiser says the BTD 700 can be used as a portable Auracast broadcaster for outdoor movie nights, help stream favourite albums with incredible fidelity, or make crystal-clear conference calls on a more comfortable pair of headphones, such as the MOMENTUM 4.
Sennheiser BTD 700 additional information

Sennheiser says that the BTD 700 has high-definition audio codecs up to 24-bit/96 kHz for Bluetooth sound without compromise. This, it says, is ideal for adding aptX-Adaptive and aptX Lossless streaming capability to music, movies, and games, even on devices lacking native aptX support
A dedicated Game Mode delivers audio latency as low as 30 milliseconds on supported headphones, keeping sound in sync with fast-paced visual action.
And Auracast support allows users to share audio to multiple Auracast-enabled audio devices, making it perfect for broadcasting entertainment and educational content.
Thanks to the Bluetooth LE Audio codecs, Sennheiser says it offers superior voice quality for reliably clearer calls and video chats compared to basic codecs.
The BTD 700 begins shipping June 3, 2025 from select retailers and sennheiser-hearing.com, with a retail price of £44.99 or €49.90.