Speaker Impedance Selector???

[Antoneo]

I have just bought a Yamaha RX630 and have hooked it up to my Paradigms. From the website, I have gathered that the Paradigm Studio 60s, CC, and atoms are all "compatible with 8 ohms". Right... I have usually seen manufacturers directly state 8 ohms or 6 ohms but I am not too happy with the "compatible" part. Well I have been in a hurry to listen to them and managed to connect all of the speakers without looking at the impedance selector. The system works, albeit dissapointed because the sound didn't have the wow! effect on me.

From the manual (I should have read this before), "Switch in LEFT position: If you use one set of main speakers, the impedance of each speaker must be 4 ohms or higher. If you use two sets of main speakers, the impedance of each speaker must be 8 ohms or higher. Center and Rears must be 6 ohms or higher."
"Switch in RIGHT position: If you use one set of main speakers, the impedance of each speaker must be 8 ohms or higher. If you use two sets of main speakers, the impedance of each speaker must be 16 ohms or higher. Center and Rears must be 8 ohms or higher."

BTW, I have only have one set of speakers as the mains. I have had the switch in the LEFT position for a day now and have listened to probably 6 hours of music so far. Have I done any damage to the speakers or amplifier? What switch position do you guys recommend?
Is there any effect on the music by the position of the switch? I do not understand the point of the switch if it says if "use this position if greater than 4" and then "use this position if greater than 8".. ::
Sorry if this seems stupid... I'm a newbie at this stuff and still learning.

 

[mithrandir2001]

Well, speakers shouldn't have a sticker that says "compatible with 8 ohms". That's what the amp should have, not the loudspeakers. The loudspeakers will say that they ARE 8 ohm (which is a false statement because impedance is not linear across frequency) and sometimes also a minimum impedance rating. The lower the impedance, the tougher a speaker is to drive. Yahama, Onkyo, Denon, HK class receivers can handle 6 ohm speakers fine. In fact, my Onkyo receiver drives a pair of speakers that have a minimum impedance of 3.8 ohms and it doesn't seem to have any problems.

Leave the switch in the left position. If your receiver can't handle the load, its protection circuitry will shut it off so it's hard to damage it. Your speakers should be fine. They will be damaged if the receiver clips (i.e. it can't deliver the current needed for a musical peak, so it just chops off the top of the wave and your speaker voice coil takes a beating) but you'll hear this. Paradigms are easy-driving speakers...your Yahama will drive them fine.

 

[Antoneo]

What exactly does the impedance selector do? I understand that lower impedances means more current is needed (I=V/R) but if the speakers themselves are ~8 ohms then isn't the "switch" useless?

 

[Viperoni]

I think the switch controls some sort of compression/limiter circuitry, so the amp doesnt heat up as much.
Not really sure, though, I needed to set it to the lower impedance mode for my friend speakers (off brand 6.5inch woofers + piezo tweet), but not mine. Oh well.