These Bluetooth adapters enhance your audio experience by including Hi-Res aptX Lossless and LDAC capabilities, as well as various other functionalities.
Spotify boasts 268 million premium users. That’s 268 million extra reasons to be thrilled about the inclusion of lossless audio in their premium subscription. The only catch is that your smartphone or tablet is preventing you from fully enjoying that subscription.
For instance, the Google Pixel 10 series does not support one of the top Bluetooth codecs favored by audiophiles, aptX Adaptive Lossless. Moreover, if your headphones lack LDAC support—which Pixels do—you won’t be able to optimize your Pixel’s audio performance.
But don’t worry! New Bluetooth adapters from Sennheiser and Questyle aim to fill the void for phones, tablets, gaming consoles, and laptops or desktops that do not support optimal connectivity to the finest earbuds through the latest Bluetooth codecs.
I’m here to guide you on how to utilize these adapters to extract the utmost audio quality from your device of choice!
Today, we’re examining the Sennheiser BTD 700 and the Questyle QCC Dongle Pro Bluetooth transmitters, both launched in 2025. These Bluetooth adapters bypass the internal Bluetooth components of your device to deliver top-notch audio to your Bluetooth earbuds, headphones, or IEMs. That’s all there is to it. If you’re familiar with computer terminology, consider these transmitters as external “sound cards.”
I’ve been alternating between the two adapters for a few weeks, assessing them with phones, as well as a Surface Pro 11 and an iMac Pro. With a few quirks here and there, they generally fulfill the expectation of providing seamless plug-and-play functionality.
Included with each device is the transmitter, along with a USB-A to Type-C adapter, allowing compatibility with laptops, computers, or gaming devices lacking USB-C ports. Other than the manual, that’s all you get. I’ve connected both adapters to phones encased in cases without any fitting issues.
Each unit features a single status LED. For the BTD 700, snap a photo of the menu page displaying the LED status guide and save it in a folder in your gallery, as it does not come with a companion app for smartphones or tablets. Operating it is quite straightforward, as you merely press the button at the bottom of the adapter to switch modes/codecs.
The QCC Dongle Pro includes a mobile app, making it far simpler to determine which Bluetooth codec is currently in use. It also displays all of your paired Bluetooth devices.
The Android ecosystem varies significantly regarding Bluetooth compatibility for high-end hi-res wireless aptX codecs, LDAC, or LC3 with Auracast. The BTD 700 accommodates aptX Adaptive, aptX Lossless, SBC, and LC3 (with Auracast), while the QCC Dongle Pro also supports those codecs, minus LC3 but adds LDAC.
Audio quality from both adapters is outstanding. If you are using a device that doesn’t support outputting LDAC or AptX Lossless, you’re in for a delight! Naturally, you will also require a receiving device that conforms to those standards. Some of the finest noise-canceling earbuds, like the Noble Rex5, or the top-rated ANC headphones like Bowers & Wilkins’ superb Px7 S3, meet this requirement perfectly.
One of the advantages of these adapters is their range. During testing in a flat park, I could walk 225 feet away from a Bose SoundLink Plus before the Pixel 9 lost connection.
At home, with the adapter connected to a device in my living room, I was able to walk into the bathroom at the end of my apartment, where my Wi-Fi typically falters, and maintain a strong signal with no interruptions.
For desktop/laptop applications, I’ll hand the win to the BTD 700 for its robust Windows and macOS applications.
They allow you to use Sennheiser’s device with a computer as effortlessly as Questyle’s works with smartphones and tablets. The added advantage is that the BTD 700 accommodates Auracast, enabling you to initiate broadcast mode, designate a broadcast name, and even set a broadcast password if you wish to keep things private among the devices you’re transmitting to.
However, the adapters do have their peculiarities. The QCC Dongle Pro features only one LED color for the high-res codecs, preventing you from knowing if you’re streaming aptX Lossless or LDAC, for instance. You’ll need to refer to the app to find that out.
As the Sennheiser BTD 700 lacks a mobile app for pairing, you will have to set both the adapter and listening device to pairing mode.
