Network Speaker Cables & Ferrite Cores

Network speaker cables have been around for some time and companies like MIT and Transparent Audio utilize networks in the speaker cables that they offer. The network itself is usually a series coil and a series-RC network (Zobel) across the speaker connections that provide a low-pass filter for noise suppression. Transparent also offers a “Brick Network” which can be added to existing speaker cables.

A different approach is taken by LessLoss with their “Firewall for Speakers” which consists of custom-made ferrite cores that are installed between the speakers and the speaker cables. They’re quite pricey and a set of four, as required for a stereo pair, is $1656. Being a frugal audiophile, I decided to experiment with TDK ferrite cores (CAT2032-0930) that I had used in other applications. Total cost for four is $10, which certainly makes for a cheap experiment.

The TDK ferrite core is split so that it can be placed around the cable conductors and the latches lock it into place. I initially started with one ferrite core on the positive (+) lead to each speaker. Listening to recordings that I’m very familiar with, I found that the brightness of the Kef LS50 speakers in my “lively” listening room was noticeably reduced, which made for a more relaxed listening experience. At that point, I then added a ferrite core on the negative (-) lead to each speaker. The result was a further reduction of the brightness with an added sense of warmth and refinement. With awareness of the placebo effect, I repeated the experiment two days later and confirmed that the positive change brought by the ferrite cores was real and quite noticeable.

If you’re dissatisfied with the bright irritating sound of your system, the ferrite cores might be worth a try. As an added FYI, the TDK ferrite cores are available in various sizes (and strengths) that allow for fine tuning.

https://product.tdk.com/info/en/catalog/datasheets/clamp-filter_commercial_zcat_en.pdf