Axiom Home Page Forums General Discussion Technical Questions Help! Receiver Impedance Setting - 6ohm or 8ohm ?

Have just connected all speakers to my Yamaha 1400 receiver. Yamaha manual states that if you are using 6ohm spkrs to chg the impedance level from 8 to 6 before powering on. I have M60's and VP150 which are rated at 8 ohms but my QS8's are rated for 6 ohms - which setting do I choose ? Any information would be appreciated. Thank you ... Paul

Paul, despite the suggestion in the manual, leave the setting at 8 ohms(even if you were using 4 ohm speakers)unless in the highly unlikely circumstance that the receiver would keep shutting off. The 6 ohm setting limits the amount of voltage available at the rails in the power supply section of the receiver and therefore also limits the maximum power available. The form of Ohm's law relevant to this is I=E/R, i.e current in amps equals voltage in volts divided by speaker resistance in ohms. A lower impedance speaker therefore would allow more current flow(possibly causing overheating)at the same voltage, so the lower impedance switch or setting cuts down the voltage. Don't worry about it, the 1400 can handle 6 ohms at the 8 ohm setting with no problem.

JohnK .... Thank you very much for the information and for taking the time to reply so quickly .... greatly appreciated ... I will leave the setting at 8 ohms on the Yamaha 1400 ...

I kinda figured it would work fine leaving the amp in 8ohm mode. Just curious if anyone has any issues in doing so. Like overheating etc since technically you'd be out of spec of the amplifier (drawing more current than normal when at high volumes).