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What does switching back of amp from 8 to 4 ohms do?

I have three speakers including a center and the left and right are connected to 4 ohm jacks on the back of the 600 W mono blocks i have.
I have a Multi channel amp that has 250 W and only have the center connected to it. The switch on the back of this app can toggle between four and eight Ohms.

If I change the switch on the back of the multi channel amp from 8 to 4 Ohms how will things be impacted?

Will volume levels be reduced? Impact to sound quality? Good idea?

I use 4 ohms for the main speakers as I was told it would be better since I have more than enough power to drive them. Not sure what difference it makes

Thought changing the center speaker to 4 might be good to be consistent with the left and right speakers

jumia
gregdude
222 posts
 

@russ69 you said all the above answers are wrong but don't say how, I'm curious if you want to back that up.

clearthinker's avatar
clearthinker
1,582 posts
 

@gregdude 

You're right Greg.  Russ's answer is pretty much the same as most of the others.

Very few speakers have traces that don't go below 6 ohms.  Ergo very few speakers should be connected to the 8 ohm tap.  Mainly only 'full-range' horns and that kind of rarely used stuff.

Also consider the phase angle.  Bad combinations of phase angle and low ohms at particular low frequencies mandate the 4 ohm tap.  Read John Atkinson's tests in Stereophile.

jumia OP
528 posts
 

Another situation where lots of brilliance has mixed in with lots of confusion. 
 

Maybe a different approach here is in order, maybe trying to understand the mechanical wiring differences Beyond the four and eight ohm taps. Clearly there are wiring differences within the speaker cabinet relating to four and eight ohms. What are these differences which seem to have operational merit.

 

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