Resistors with a very high resistance, such as those rated at 10,000 megaohms (10 G), are infrequently found directly within the primary audio signal path of car audio systems. Their application generally lies in areas where minimizing current leakage or providing a very high impedance path is crucial, often related to safety or diagnostic circuits. One example might be in isolating sensitive circuits or providing a discharge path for capacitors in high-voltage power supply sections within the amplifier, if present. This high resistance value ensures that any current flow is negligible, preventing unwanted noise or interference in the audio signal.
The importance of such high-value resistors stems from their ability to effectively block DC current while allowing for the dissipation of static charges. In automotive environments, where electrical noise and voltage spikes are common, these resistors can play a crucial role in protecting sensitive electronic components. The benefits include improved system stability, reduced risk of component damage from electrostatic discharge (ESD), and enhanced safety by preventing the buildup of dangerous voltage levels. Historically, high-value resistors were less common due to manufacturing limitations, but advancements in materials science and production techniques have made them more readily available and reliable.