This is a Cambridge Soundworks Desktop Theater 5.1 DTT2200 as pictured. It's a good few years old now and was working fine but has lately developed a problem. Essentially the volume fluctuates without the volume control being touched. This happens on my daughter's PC as well as my own. Maybe it's a Win11 issue - I've had a look at various forums but nothing seems to solve the problem. The speakers I am currently using are working fine so I don't believe it's anything to do with my PC. Maybe it will work fine for you. It does require 5.1 sound output from your PC - green, orange and black sockets or the ability to remap other input/output sockets.

PC Speaker Set (Codsall WV8)