Low-voltage wiring

Due to bad planning and impulse purchases, I've got a bunch of devices (2 Keces linear power supplies, a PC/renderer, exaSound e12 DAC, Rega turntable power supply, USB Regen, UltraCap LPS-1, fiberoptic media converter, and Bluetooth receiver) connected by 5.5-mm barrel plugs and some cheap two-conductor wiring. Voltages range from 5 to 24. I've noticed that some equipment (like the Keces LPSs) comes with ferrite beads on coaxial cable, presumably to reduce RF output and/or magnetic field generation. Should all the wiring be like this? Is this type of wiring likely to interfere with interconnects or speaker wire? I don't really hear anything, but am always interested in incremental, low-cost improvements. 

Any thoughts would be appreciated, and if there's already a thread on this topic please point me to it.