Anyone else seeing lights dimming at idle in their car audio setup?

I’ve looked all over this forum and online but keep getting mixed answers. My setup: I have a 2019 Ford Flex with a 170A alternator and I’m running a Kicker CXA1200.1 to power my dual 12" L7S Solo Barics. I also have an AGM battery. The issue is that my lights dim when the bass hits, but only at idle, like at a red light. When I’m driving, I don’t see any dimming at all. I’ve read that some dimming at idle is normal and that as long as there’s no dimming while driving, it’s fine. Is there any truth to that? Or should I be thinking about fixes?

Yep, that’s totally normal. When you’re idling, the engine RPM is low, so the belt and alternator are running slower. But when you’re driving, they speed up.

Laken said:
Yep, that’s totally normal. When you’re idling, the engine RPM is low, so the belt and alternator are running slower. But when you’re driving, they speed up.

That makes sense and is kinda what I thought, but I just needed to double-check. I’m good with PC builds, but car audio and electrical stuff, not so much! Thanks for clearing that up.

Exactly. At idle, the alternator produces less power, so if the amp is pulling more power than the alternator is providing at that low speed, it’ll cause dimming. As soon as you press the gas, the alternator kicks in enough to handle everything.

@Oli
Thanks for confirming!