Here is a summary of how nominal impedance affects the power output of a speaker:
- Nominal impedance is the rated or advertised impedance of the speaker, usually 4, 6, or 8 ohms. It is an approximate average value.
- Actual impedance varies across the frequency range due to the speaker’s reactive components. The minimum impedance determines the maximum current draw.
- Speakers are rated for power handling based on the nominal impedance. But the amplifier sees the actual minimum impedance.
- If the minimum impedance dips below the amplifier’s rating, it could overload the amp or cause distortion.
- Lower nominal impedance allows more current flow through the voice coil, enabling higher power handling. But the amp must be capable of driving lower impedances.
- Higher nominal impedance speakers are generally more efficient as less power is lost as heat in the voice coil.
- Proper impedance matching between rated nominal impedance and amplifier rating is important for getting the rated power handling from the speaker without issues.
- Nominal impedance affects power output indirectly by enabling a certain power handling rating. But the actual impedance determines how much power the speaker draws from the amp.
In summary, nominal impedance sets a power handling guideline but actual minimum impedance determines how much power is delivered to the speaker. Matching ratings prevents amplifier clipping or damage.
Citations:
[1] https://geoffthegreygeek.com/understanding-speaker-impedance/
[2] https://www.jensentone.com/speaker-impedance-power-handling-and-wiring
[3] https://en.wikipedia.org/wiki/Nominal_impedance
[4] https://www.aperionaudio.com/blog/the-truth-about-speaker-impedance
[5] https://mynewmicrophone.com/the-complete-guide-to-speaker-impedance-2%CF%89-4%CF%89-8%CF%89-more/
[6] https://www.hifireport.com/speaker-impedance/