Recommended Headphone Impedance Range
Recommended headphone impedance is the load range an amplifier is specified or recommended to drive.
It describes the headphones connected to the output, not the amplifier’s own output impedance. A minimum-only value sets a lower load limit rather than a complete range.
Recommended Headphone Impedance Range — Headphone Amp
This range provides one part of headphone matching. A headphone inside it may still need more or less output depending on sensitivity, so the range is not a promise of the same available level with every model.
Compare the headphone’s nominal impedance with the recommended range, then examine power at a relevant load and any output-specific conditions. Keep the amplifier’s source impedance separate. A power rating measured into one load should not be interpreted as the full supported range, and a wide range alone does not establish low noise with sensitive headphones.