Here are a few key points on the minimum power output of an amplifier when connecting a 4-ohm speaker:
- The minimum power the amplifier can deliver depends on its rated power at 4 ohms. This is usually lower than the 8 ohm rating.
- For example, if an amp is rated for 100W at 8 ohms, the minimum at 4 ohms may be around 50-60W.
- The formula for minimum power into 4 ohms is:
Minimum Power at 4 ohms = (Rated Power at 4 ohms) / (Number of Channels)
- So a 2-channel amp rated at 100W per channel at 4 ohms can deliver a minimum of 50W total into a 4 ohm load.
- The actual minimum may be a bit lower than the rating due to real-world factors like impedance dips.
- Operating an amplifier near minimum power reduces headroom and increases distortion. More power is better.
- Driving speakers to maximum volumes near an amp’s minimum power can risk damage from clipping.
- Check manufacturer specs for the 4-ohm minimum power rating before connecting a 4-ohm speaker.
In summary, the minimum power depends on the amp’s 4-ohm rating divided by channels. Stay safely above the minimum to allow headroom and avoid distortion issues.
Citations:
[1] https://geoffthegreygeek.com/speaker-impedance-changes-amplifier-power/
[2] https://audiokarma.org/forums/index.php
[3] https://electronics.stackexchange.com/questions/198528/how-do-i-set-up-speakers-in-series-and-or-parallel-for-a-minimum-4-ohm-load-on-t
[4] https://www.crownaudio.com/how-much-amplifier-power
[5] https://www.thegearpage.net/board/index.php
[6] https://en.community.sonos.com/components-and-architectural-228996/amp-is-ok-with-4-ohms-impedance-speakers-6860914