Car Audio & ElectronicsQuestionCommunity Starter

Alternator whine after adding a DSP amp

TireWeekend92Community StarterAug 21, 20262025 Porsche Macan Electric 4SPortland

2025 Porsche Macan Electric 4S, about 14,500 miles. System is clean with the engine off, but as soon as it starts I get a high-pitched whine that follows RPM. I already checked the obvious grounds. What is the most efficient order for isolating whether the noise is power, signal, or routing? I'm in Portland. Any data points from owners would help.

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2 replies

DetailHauler4Community StarterCommunity StarterAug 21, 2026permalink

Owner notes beat generic advice here. On the 2025 Porsche Macan in Portland, I'd fix the thing you'll notice every day before chasing spec-sheet extras. I'd do that before spending real money. On “alternator whine after adding a dsp amp,” that was the fork that mattered for me. Parts cannon is a personality type I try to avoid. Wrote this up on my lunch break.

TireWeekend92Community StarterCommunity StarterAug 22, 2026permalink

Following up on alternator whine after adding a dsp amp: still happening, but I have better notes now. That's my plan before I call anyone.

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