I apparently fried my Yamaha R-S201 receiver by attaching 4 Bose 151 4ohm speakers to the system; 2 on the A side and 2 on the B side. My question is if I buy another receiver that requires minimum 8ohm can I attach all four speakers to either A or B to gain needed ohms; 2 speakers on left and 2 speakers on right? Did not know the ohms made a difference
You wired the two speakers per channel in parallel (all the wires going back to the receiver). To get 8 ohms with 4 ohm speakers you have to wire them in series. That would be red receiver to red speaker 1. Black speaker 1 to red speaker 2. Black speaker 2 back to receiver black.
Though technically you can wire two 4 ohm speakers to produce 8 ohm load to the speaker it is not a recommended configuration as each speaker sees the other speaker in its signal path and sound quality lowers.