ohms

Hello I think i have a decent grasp on OHMs, and there application, but then again maybe not... I've got 2 4ohm MTX 225RMS SVC 10"s that i've already made a box for and mounted, and am currently looking for an amp. Now i've always set my speakers up parellel...but alas, all set-ups i've made the amp fit the set-up (meaning that if i had 2speakers, i had a 2channel amp, 4speakers, 4channels so all speakers had there own channel. But i'm now looking at a wiring chart that came with the speakers, ans this is what i'm lookinh at. I see that with a 1channel amp, a SVC 4ohm speaker ran paralel has a 4ohm load, and 2 4ohm speakers has 2ohm load, 4 4ohm speakers has a 1ohm load. But, with same 1channel amp 1 6ohm DVC speaker parellel has 3ohm load, while same the speaker ran in a series has a 12ohm load. Why is that? Also, 1channel amp 6ohm speaker with coils AND speakers ran parallel, 2DVC have a 1.5 load, while same 2 6ohm speakers with coils wired in series and speakers parallel, they present 6ohm load. I guess i've never run into this problem before cause i never really looked at it that way, and i've only made 1 dual voice coil set-up. Can someone give me some better insight on OHM impedence? What happens if OHM drops below recommended usage? Also what kinda amp do you recommend for my speakers? Thanks in advance Look twice, think thrice, 1 splice/ 1 slice!

This is a phrase i came up with and something i will now live by.