Hello everyone,
I also have the Logitech Z623 speakers and found a solution for myself.
to start with something, I will tell you a little story about this.
I bought the Logitech Z623 speaker set (2 speakers and 1 Woofer) in november 2011. I was really happy with the speakers until about 1 year later they started to give some crackling in the following situation:
1. When I turn on the speaker it will give a "light" crack in the left speaker.
2 When the volume is over 40% with Bass on 50% the sound will start crackling in both speakers.
3. I have the Volume and Bass on 100% at the speakers and maintain the sound via the windows audio mixer (at 40%).
I tried everything and read about the issue on much forums around the world. I simply forgot to check the "Tone" balance which shows the Bass/Treble in the windows audio settings. I have put this at -12 dB and notice I can put the speakers on 100%. This was a great break for me because I was about to thrash these speakers because I had no warranty for it. I have no issues left and still checking which is the most appropriate setting for maximum performance and sound.
Now you guys are probably thinking I am not getting the maximum performance because I have put the dB for Bass/Treble to -12. Actually when I have the "Tone" levels to the middle with the speaker setup to 100%, this means I would have 150%... correct? So thats why I think we have the issue because after some time we blow our speakers... So yes we have to do it with that if you have no other help from Logitech with out of date warranty.
I hope this info will help you guys out. If you need any assistance I can help you with remote support. My education is actually in IT, so I know my way around
