I just recently bought and set up the Logitech Z623 2.1 Speakers a few days ago, and I've just noticed a low-key, constant crackling noise coming from specifically and only from the left speaker whenever the speakers are turned on. It isn't affected by volume on the speakers or computer as far as I can tell, and it seems to continue while playing sound, though it doesn't seem usually noticeable at that point. I don't think it's been doing this since I set it up, though.
I unplugged the speaker's input entirely, and the crackling continued whenever the speakers were on regardless, so I get the feeling it's not a software issue.
