Problem with old Creative 2.1 and possibly looking for a replacement

Hello everyone, I'm new to this sub. I have an old Creative 2.1 set (I believe the model is I-Trigue 3300) and recently I am noticing a sound coming from the speakers, some kind of interference, like something is frying (just to explain the type of noise). It is very low but in a silent room I can notice it and it is annoying. The noise is present even if the audio cable is not connected (so it's not a PC problem) and even if the speakers are connected to another electric socket in another room far away from the PC (so it's not a problem of other cables interfering with the speakers).

Do I have to change speakers? Or is it something that all speakers have and I'm noticing it only now because I recently moved and my new apartment is more silent than the previous one?

In case I should buy new speakers can you suggest another 2.1 system? Possibly around 100 dollars.