Archimago's Musings: MEASUREMENTS / MUSINGS: Headphone impedance, sensitivity, efficiency, and amplifier output impedance. (And a quick thought on Darko's "All You Need Is...")
What Does Ohm & Impedance Mean In Earphones/headphones?
The effect of impedance on headphones - digitec
Effect of output impedance on headphone with a flat impedance-freq curve | Audio Science Review (ASR) Forum
How Impedance Affects Sound Quality In Headphones
Here's what you need to know about headphone specifications - CNET
NwAvGuy: Headphone Impedance Explained
Headphone Impedance Explained [2023 Guide] - Earbuds Zone
Headphone Impedance - Delivering the Right Sound | Addicted To Audio
How does an amplifier's output impedance affect the sound of headphones? - Quora
Advice new headphones - Gearspace.com
Headphone Impedance Demystified: Do I Need a Headphone Amp? - Headphonesty
Headphone Impedance Demystified: Do I Need a Headphone Amp? - Headphonesty
Understanding Impedance and Why it Matters!
DO OHMS/IMPEDANCE MATTER IN EARPHONES AND HEADPHONES? - 1MORE
What is Headphone Impedance? [Definitive Guide] - Home Studio Basics