Speaker Impedance and Receiver

For speaker set-up in my Yamaha receiver it marks :

4 ohms or higher for each speaker if set A or B is used and
8 ohms or higher for each speaker if sets A and B are used

Currently I am using 2 sets of front speaker A and B at the
same time. With A and B, I am connecting to 2 pairs of 8 ohm speakers.
However, in speaker specifications it indicates minimum ohm = 4.3
If it's the case when speaker impedance goes to minimum (4.3) will
it fry or toast (burn) the receiver ? Thanks

Andy

Receiver : Yamaha RXV-420
Speaker : BW DM-303

those extra 2 cnannels(B) are just a parralled set off the others(A). They sometimes call it daisychain.........

Your amplifier should not have a problem with the variations in impedance of your speakers if this 4.3 Ohm is a minimum impedance of an 8 ohm rated speaker.

On the other hand, sound quality will definitely be comprimised, when your volume and musical reproduction frequencies cause the speaker to reach its minimum impedance if both speakers are connected (amp will probably clip at a lower volume level than if you had only one set connected).

This comment does not mean you can abuse the speakers and amp.

If you plan on keeping both speakers on for a few hours at maximum volume, or are having a party, where any fool can crank the volume to max without warning, use only one set of speakers and risk blowing a speaker before injuring your amp. (you should hear a lot of clipping before you cause damage to your speakers or amp)

When using A + B speakers in this scenario your receiver will see an impedence as low as 2 ohms. I would NOT run both A + B speakers at the same time with this system. Your receiver will overheat and shutdown with anything but the lowest volumes.