These days, Bluetooth technology is at the heart of nearly everything. It’s how the wireless controllers on your game system connect with the console itself. It’s how your phone instantly connects to the stereo in your car when you put the key in the ignition. It’s also how you enjoy wireless audio on everything from smartphones to speakers to soundbars, headphones and more with technology like aptX
Understanding the history of Bluetooth, along with its relationship to technologies like aptX, puts you in a better position to understand the unique benefits it brings to the table.
Though Bluetooth itself (at this point dubbed Bluetooth 1.0 or 1.0B) had been around for years, the first major version of the Bluetooth Core Specification that consumers would have interacted with was released in 2004. It fixed a lot of the problems inherent in those early Bluetooth devices – like the fact that the connections would sometimes make accessories inoperable – and fixed them. It also used a technology called EDR (or “Enhanced Data Rate”) to allow for transfer speeds of up to 2.1 Mbit/s.
The next major revision came in the form of Bluetooth 3.0, which was originally released to the world in April of 2009. Bluetooth 2.0 provided theoretical data transfer speeds of up to 24 Mbit/s, though not over the Bluetooth connection itself. With Bluetooth 3.0, the technology used the actual Bluetooth link to simply negotiate and establish a connection between two devices. The actual high rate data transfer was handled via a collocated 802.11 link, similar to the one that the wireless router in your home is probably using right now.
Next came Bluetooth 4.0, which made its debut in June of 2010. It included a few different ways of transferring data, like Classic Bluetooth and Bluetooth High Speed. Classic Bluetooth used legacy Bluetooth protocols to transfer data, meaning the same ones that had been in use for years prior. Bluetooth High Speed was actually based on current Wi-Fi standards and transferred data in largely the same way.
Bluetooth and aptX
Modern Bluetooth protocols are also used with a wide range of other complimentary technologies, with aptX being a notable example. The aptX audio codec is widely used in everything from consumer to automotive applications for real-time audio streaming. Although aptX was first developed back in the 1980s, it makes a perfect companion to Bluetooth for a number of reasons that music aficionados in particular can appreciate.
Provided that aptX is supported by both the source device (like a smartphone) and the paired accessory (like a speaker), this codec can be used to instantly transmit lossy stereo audio over a wireless connection in a higher quality way than the default SBC codec mandated by the Bluetooth standard. SBC, for example, supports bit rates of up to 198 kb/s for mono streams and 345 kb/s for stereo streams. On the other hand, the aptX HD codec supports streams of up to 576 kb/s. This means that not only is audio less compressed (and therefore better sounding), but data is also being moved between those devices much faster – thus reducing any lag at the exact same time.
So though Bluetooth itself naturally supports wireless audio streaming via SBC, only aptX offers less compression, higher bit rates and faster streams – creating a better, more natural listening experience at the exact same time. aptX takes Bluetooth audio streaming out of the realm of simple convenience and into something that even hardcore music fans can appreciate.