Review on Topnisus [Pack of 10] Clip-on Ferrite Core Ring Bead Cable Clip - Anti-Interference Filter for RFI EMI Noise Suppression, High-Frequency Optimization (5mm Inner Diameter) by Fernando Beck

These ferrite cores arrived on time as expected. And they work well enough to boot. Unfortunately for me they weren't enough to mitigate the signal noise I experienced with two different pairs of USB powered PC speakers. These are Revain Basics USB powered speakers and Dell AE215 USB powered speakers (no subwoofer). Both sets of speakers suffer from severe signal noise when powered by the host computer when connected to the 3.5mm jack. I added a strand of wire to the audio cable near the source and near the speakers themselves, and the signal noise was significantly reduced, but not eliminated. I then added a wire to each end of the USB power cable again and the signal noise was further reduced! Unfortunately, the signal noise of both pairs of speakers was so strong that even 4 ferrite cores could not completely eliminate the noise. .While these cores aren't necessarily made for this particular application, I'm keeping them for posterity because they work well, they just can't get over the really, really awful signal noise. Also, I'm not entirely sure what ferrite cores are actually for. So maybe I'm just a fool. Well, it was cheap and a good learning experience.