I have a mobile headset setup which could be summed up like this:
phone→30cm cable→aluminum box→ 100cm cable → headset
The aluminum box is 50x50x20mm and contains one potentiometer and 2x 3.5mm female plugs to separate the mic and audio signals at will.
I want to place a ferrite bead to reduce EMI coming from the mobile phone.
It would be a lot more convenient for me to have the ferrite bead inside the aluminum box instead of outside...
Is there any reason important enough regarding sound quality or EMI removal to convince me not to place the ferrite bead inside the aluminum box (instead of outside- on the 30cm cable)?
Should the aluminum box be grounded in any case?