4 / 8 ohm switch

[2tone]

Talking about a Pioneer M90 amp here..

4/8 ohm volt rail switch

I see that it changes the rail voltages. I understand the basics of what the switch does... question comes then when ...

If I am running 6.3 ohm speakers what is the best setting and also taking into consideration 25 feet of 10awg wire to the speakers? Will the long wire make a difference? I don't run the amp at any crazy level but the EQ is tweeked and also I have SUPER BASS on the preamp that packs a wallup if you will...
I run latop base type 5v usb fans on top of the amps to keep the airflow in check...

I don't here any major difference, since the amp stats 2ohm loads? Not sure if that means it can handle them... I find if I drive 2 pairs of 6.3 ohm speakers in parallel she does sound much better on the 4 ohm setting... less clipping of the tweeter protection circuit on the DSS9's, which I guess would mean the amp is distorting the high frequencies more?

Set me straight.

 

[Jon_Logan]

Use the "4 ohm" setting.

You only need to worry about the "8 ohm" setting if you are running into clipping very easily with the "4 ohm" setting.

The difference in rail voltage should not be so much that you notice a change in maximum (clean) output capability.

Meanwhile, at the "4 ohm" setting, the output devices will run cooler and be working in conditions that will make them more reliable.

 

[NEMOaudio]

In simple terms it reads:
"Use speakers with 4 ohm or more" on 4 ohm setting.
So it is not recommended to use a 6.3 ohm speaker with the
"8 ohm or more setting"