Impedance
Definition
Impedance is the AC load the amplifier sees. “8 Ω nominal” still dips; a 6 Ω bookshelf can look like 4 Ω in the bass. AVR wattage is usually specified two-channel into 8 Ω; 6 Ω numbers are higher current, not free headroom. Match the receiver’s 6 Ω or 8 Ω rating to the speaker’s nominal load, then check the minimum impedance in the manufacturer PDF.
Calculators that use this
Amplification & power
Amplifier Power Match (SPL) Calculator
From speaker sensitivity, distance and target SPL, get required watts and whether a receiver can supply them with headroom.
Amplification & power
Speaker Wire Gauge (AWG) Distance Calculator
Pick a minimum AWG so round-trip copper stays under 5% of the speaker impedance on your cable run.
Amplification & power
Ohm’s Law AV Rack Load Calculator
Convert rack watts and wall voltage into amps and check the 80% continuous-load breaker rule.
See every term in the home-theater glossary or browse all calculators.