How Do I Change Change From 8ohms To 6 Ohms On My Receiver Manually?

"The issue is heat buildup. The switch is there to help the receiver pass UL or CSA heat safety tests when driving lower impedence loads. When in the 8 ohm position, the receiver outputs it's highest potential wattage. The 4 ohm position lowers the output section's power supply voltage, thus lowering the overall possible heat buildup/wattage. (Measurements I've seen range from around 20 to 40 percent less power at the 4 ohm setting than what's available at the 8 ohm setting.)

You want to consider heat related problems (when using lower impedence speakers in the 8 ohm position) versus the higher risk of amplifier clipping (when running the receiver at high volumes when in the 4 ohm position.) Too much heat can mess up your receiver and clipping can eat tweeters.

Bottom line...

It kinda comes down to ventilation. If your receiver gets a good, constant breath of fresh air, then you're probably fine with the 8 ohm setting. (BTW, don't stack ANY components on top of your receiver. Even slightly blocking the top can cause heat buildup.) But if your receiver gets very warm and you can't really improve the ventilation, then you might want to consider the 4 ohm setting."

The short answer is try the 8 ohm setting. Just check the top to the receiver to see if it is getting too hot. A lot will depend on your listening preferences. If you don't go for Rolling Stones Live levels then you may not have the slightest problem even with some 4 ohm speakers. However, if you really like it loud and are driving surrounds also the current transformers of your receiver probably won't keep up as well. A 6 ohm load is probably in the range for most receivers. But again, keep an eye on the heat at first. It is OK if it gets warm but not hot.