Impedance
Impedance is how much a speaker resists current, measured in ohms. Lower impedance demands more current from the amplifier.
8 ohms is the easy load most modern AVRs are designed for. 4 ohms is common with high-end speakers but only some AVRs are rated to drive it continuously. When in doubt, check the AVR's minimum impedance spec.
Related topics
- Speaker SensitivitySensitivity is measured in dB SPL at 1 watt from 1 meter. Every +3 dB of sensitivity is roughly like doubling your amplifier power.
- AVR vs External AmplifierAn AVR is the brain: it decodes formats, processes audio, and powers speakers. An external amp only adds power — never channels or processing.
- Understanding Speaker TypesBookshelf, tower, in-wall, in-ceiling, on-wall, and satellite speakers each solve a different placement problem.