Re: What a great site!
The equation for parallel resistances (and impedances) is thus:
1/R1 + 1/R2 = X, 1/X = Rtotal
I'm no math whiz so forgive if the formula isn't expressed correctly. But for the two impedances you mentioned, 4 & 2:
For more than two parallel resistances, just keep repeating the 1/X + string for each and then divide 1 by the total.
Owner, Audio Anarchy, LLC
2915 Youree Drive, Shreveport, LA
Get your CT Sounds, Execution Audio and other high quality car audio gear from me.... cause I really need the money. :-)