A whining noise that changes with engine speed is typically caused by electrical interference, often referred to as alternator noise.
This issue is commonly related to installation factors such as poor grounding (earthing) of the amplifier, incorrect cable routing, or low-quality components. For example, RCA signal cables running too close to power cables can introduce unwanted noise into the system.
Ensuring a solid ground connection on clean, unpainted metal and properly separating signal and power wiring can often resolve the issue.
If the problem persists, we recommend having your system professionally inspected by your localFocal Australia authorised car audio dealer to identify and correct the source of interference.
