Maybe this is not easily answered but my question is this: If my amp is rated at 80 wpc into 6 ohms, is it more desirable to buy speakers rated at 4 0hms or 8 ohms? Thanks in advance for any responses. John
Hi John,
Several aspects need to be considered. Will use tube amps as an example since you use power output at 6 ohms, an unusual spec.
1) Distortion specs are probably given with a 6 ohm resistive load.
2) As you know speaker impedance varies across the audioband. An 8 ohm speaker can easily dip below 6 ohms at some frequency(ies) and rise well above 8 ohms, and a 4 ohm speaker can easily dip below 3 ohms and rise well above 4 ohms.
3) I will say "usually" as the load "resistance" increases, power output decreases. Harmonic and IM distortion also decreases. In general driving an "8 ohm" speaker should cause less harmonic and IM distorton than using a "4 ohm" speaker.
4) The damping factor will change. The damping factor will be higher using the 8 ohm speaker than using the 4 ohm speaker. Around bass resonance, this is a probably true as well, but I will not say "always, 100%".
5) Soundwise, you will just have to audition with both and see which you like better.
Cheers.