Speaker Ohm Ratings - Need Help

[MyKill Myers]

Onkyo TX-SR705
Polk Audio CS1 Center (Rated 8 Ohms)
Polk Audio Monitor 50 Fronts (Rated 8 Ohms)
(4) Samsung Surrounds (Rated 4 Ohms)

I upgraded my Samsung HT-AS720ST in the last 12 to 18 months with the Onkyo and Polk equipment noted above but kept (4) of the Samsung speakers bundled in the HTIB to save $$$ in moving to 7.1 HD Audio

My questions/concerns are with the mix/match I've got going on in ohm ratings. I plan on upgrading my surrounds to the PA FXi A4 (Rated 8 Ohms) but for now in my receiver setup settings, I only have the option to set the speakers at 4 ohms or 6 ohms, not 8 ohms and I believe I have the setting set at 4 ohms.

Can someone give me or direct me to a quick speaker ohm rating 101 and let me know if setting the receiver speaker setting menu at 4 ohms is the right thing to do? Am I hurting my better PA 8 ohm speakers on my front stage? If I had (4) 8 ohm surrounds in place, would an 8 ohm setting magically appear in the Onkyo receiver for me to switch it to?

Thanks for any help in advance.

[ijokr]

check the stickies in the speakers section

[MyKill Myers]

I read Big Daddy's sticky and if I understood it correctly, I do need to leave my receiver setting at 4 ohms. Appears that when I upgrade the surrounds to the FXi A4's, I'll want to change the setting in my receiver to 6 ohms since all 7 of my speakers will be rated at 8 ohms. This should help ease some strain I've been putting on my receiver this past year-year and a half by running the 8 ohm front stage with 4 ohm surrounds.

That's two articles from Big Daddy in the last 3 days that have really helped me. (DIY Sub Riser = >)

Thanks for your help.

[Big Daddy]

In general, when you set the receiver to 6 ohm, it can handle 8 ohm speakers with no problem. The low impedance speakers are always a problem for receivers. External amplifiers can handle 2 ohm, 4 ohm, 6 ohm, and 8 ohm speakers with ease. Most receivers can handle 8 ohm and 6 ohm only.