Thank God for John Atkinson. From my long experience in reading Stereophile technical reports it's very rare that some part of a speaker's impedance curve isn't below 4 ohms. And vanishingly rare at 6 ohms. Accordingly most valve amps should almost always be set to their 4 ohm tap. If they have one. Atkinson nearly always recommends this. Flea power examples should really only be run into 'full' range horns with sensitivity in the high 90s and above.
Finding (calculating?) speaker and amp impedance
I'm starting to understand why speakers with high efficiency and perhaps more importantly a flat impedance curve work well with tube amps.
If not published by the vendor/manufacturer, is there a way to determine the impedance curve from the specs that are provided?
Also, I have a pair of Magnepans that need high current amplification.
Is there a way to determine the current of an amplifier from vendor/manufacturer provided specs?
Thanks everyone!