At first, with a charge of 30%, the sound deteriorated sharply, if it is a song, then the voice is practically not audible, only music and then of poor quality. I already wanted to return it, but I searched the Internet for a solution to the problem and it turned out that there were a lot of chips at the column with the buttons pressed in various combinations: you can reset, reconfigure. After a full restart of the column, the problem disappeared.