8ohm or 4ohm?

[adrrad]

I just want to let you know that I do not know very much about speakers and amplifiers. I got a Harman Kardon PM640Vxi, 4x45Watt + 1 pair of JVC SP-74BK loudspeakers rated 225Watt at 8ohm + 1 pair of speakers Infinity Reference 50 rated 150Watt at 6ohm. The HK is high voltage/high current integrated amp and has 4ohm and 8ohm capability as well. The idea is that I have a 4ohm/8ohm capable amp and 2 pairs of speakers: one is 8ohm and other 6ohm. My question is what output impedance to choose for amp? Is sound quality better for 4ohm or 8ohm? (The thing I noticed is that when amp is on 8 ohm the light for high voltage and the light for high current are both on. When the amp is on 4 ohm mode, the light for high voltage is off and the light for high current is on. Is sound quality better in 8ohm or 4ohm?).

Thank you in advance!

Adrian

[richie00boy]

In a perfect world the 8 ohm load is easier on the amp. In the real world the 4 ohm speakers will have completely different response to the 8 ohm speakers so you can no longer simply say one impedance or the other is better.

[adrrad]

Thanks Richie. Is there really no difference? Considering the amp and speakers I got, in your opinion, which is better for me to use: 4 or 8 ohm?

Adrian

[richie00boy]

Just try both and see which you like the sound of, forget about the ohms of them

[Stormrider]

The switch on the back of the amp that selects 4 or 8 ohm loads changes the rail voltages for the amp section. 4 ohm loads are harder on an amp so you have to use a lower power supply voltage to keep the output devices within their safe operating area.

Use the 4 ohm selection.

[adrrad]

Thanks for advices!