Can Bluetooth Be Used for Audio Streaming?

In this article, I will take a look at Bluetooth. In particular, I will focus on whether the truth is suitable for transferring audio from one location to another. Streaming audio via Bluetooth has not always been possible. In fact, Bluetooth as such was never originally designed as a medium for transporting large amounts of data such as audio data. Instead, Bluetooth was intended as protocol to connect peripherals with the computer.

In order to connect a printer to computer, for example, you can use a Bluetooth receiver which is attached to the use be port of the printer and then similarly a USB dongle which plugs into the USB port of your computer. Both dongles are going to communicate with one another by using the wireless protocol. However, the first revision of Bluetooth only supported the data rate of 1 Mb per second. If you take into account that during the transmission there will be additional data transmitted, the actual throughput is only half that. Also, the throughput depends a lot on the circumstances such as the amount of wireless interference which can degrade the data rate.

Naturally, audio by itself in uncompressed format cannot be transmitted via Bluetooth. After all, the data rate coming from a music CD is 1.4 Mb per second. That means that by using redundancy, you will need at least a channel that supports 2 Mb per second for transmitting uncompressed stereo audio.

wireless speakers with an iPod cradle

However, vendors have come up with audio compression standards that can shrink the data rate it has to be transmitted. In fact, the most modern standard which is called AAC can reduce stereo audio to as low as 64 kb per second. This data rate can easily be transmitted via Bluetooth. However, the mostly used format when streaming audio via Bluetooth is called SPC or sub-band coding. This format has been introduced almost a decade ago and allows for transmission of audio in a compressed format at the data rate of about 100 kb per second.

There are more modern streaming formats available nowadays. The latest standard support low latency audio transmission with minimum compression. As a result, since more modern Bluetooth standard support higher data rates, there will be less loss of audio quality. However, keep in mind that many people will stream music which has been compressed originally. Therefore, ideally you should stream the music in its native format without re-quoting the audio. Recording will cause distortion to some extent.