In most homes even earth ground is contaminated by noise, and the sound of a system can be greatly improved by installing an additional earth ground as near as possible to the system. The sonic benefits are similar to installing the AC-neutral and neutral-earth ground capacitors.

This is a rather laborious tweak involving driving a long copper-tube ground stake in wet ground, bringing in a heavy grounding wire to the system outlet(s). Having a licensed electrician do this is recommended.

The sonic improvement is somewhat greater if the system-connected dedicated earth ground is isolated from the noisy house earth ground, but this is not recommended by electrical codes because of possible safety problems. If both an equipment fault causing significant ground currents and poor house earth ground connection occur there could be large voltages between the two.