Speaker amplifier impedance matching

[AudioNewbie]

If I encounter a speaker with a manufacturer-rated nominal impedance of 6 ohms and an integrated amplifier rated for 8 ohms (no 4 ohms rating available), can they be paired effectively, or is there a mismatch? I found it puzzling when a highly regarded audiophile, with a channel boasting close to 250K subscribers, recommended this combination, as the impedance ratings seem to be incongruent.

 

[staticV3]

The Amplifier may or may not be super happy driving a load that may or may not have been tested during development, but there will not be an impedance mismatch.

That's because impedance matching is just not a thing in analog audio. The term you're searching for is impedance bridging, meaning output impedance « load impedance.

 

[ZolaIII]

It doesn't matter that much what is the rated speakers impedance. It maters what is their minimum impedance and where it is so how hard it will be to drive.
So you have 8 Ohms rated speakers that deep down in bass to 3 Ohms and 6 Ohms rated one's that don't go under 5. Low impedance tolerant amplifier will be able to drive it (butcher tested with such loads and designed to be able to do it of course) but let's be honest such speakers don't do any favours neither to their self (voice coils) or amplifier and will run hotter and last less. As manufacturers rarely specify minimal impedance and where it is (and in line with phase) that is one more reason to check their independent measurements if such exist.