Impedence is the combination of resistance (ordinary resistance to current) and reactance which is resistance specific to alternating current which comes from the capacitors and coils in the equipment. Even a squiggly circuit trace can create reactance. So, impedence is resistance.
Whatch this short for a clear explanation:
https://youtube.com/shorts/tanon58nW1o
From what I've read, and from talking to a guy who own a music studio near me, impedance mismatch is a real thing in audio equipment. At best, it'll lower the sound level causing you to have to crank up the volume, which just puts more strain on your equipment. Worse, it can cause crackling from waveform peaking. At the very worst, it can damage equipment.
Brushing it off just because the guy doesn't know the wavelength of audio signals is a dick move. No wonder he stopped talking to you. I bet you, yourself, know a lot of things, a lot of true things, that you can't explain to the utmost detail.
"You say quarks are combined with the strong force to make protons, huh? Well, what's the binding force between an up and down quark? Oh, you don't know? Curious."
End of story. That settles it. Case closed. No exceptions. That's final. Consider it settled. It's non-negotiable. End of discussion. That's the final word. Nothing more to add. Enough said.