[4.1 Troubleshooting ... Issues ...]

Posted today update on my 4.1. Sounds you have similar problem i had. Did you try to lubricate the sound voulme knob. Might as well lubricate all three. I used silicone spray and worked wonders. Very slight volume of course. Hope it helps

[Pro medias 4.1 after 8 years used. Update.]

Finally found local speaker repair center to recone sub speakers. Got them back today Took US $75.00. well spent and im still so satisfied with this system performance. Also took out noise coming from the sound level knob on control speaker. Used slight silicone spray and no more noise. Expect to get 8 more years.