According to this article, many wireless headphone users experience low sound quality and a lack of high frequencies when using the standard Bluetooth SBC codec. To improve sound quality, it is recommended to use devices and headphones with aptX or LDAC codecs, although these tend to be more expensive due to licensing fees. However, the article suggests that the low quality of SBC is actually caused by artificial limitations set by Bluetooth stacks and headphones’ configuration, and these limitations can be bypassed through software modification alone. By modifying the Bluetooth stack, users can increase the bitrate and improve sound quality. The article also compares the sound quality of SBC to aptX and demonstrates that SBC can sometimes produce superior results with a high bitrate.
https://habr.com/en/articles/456476/