[Dforcet]

I know that the sub and the amp have to match but what is the difference in the two different subs and which is better

[wickedimp]

Electrical impedance (ohms) should match on your products.

[Stratmando]

Impedance needs to match.(or limits of amp)
If you had 2 2 ohm speakers in series, you could hook to 4 ohm amp.
Or 2 4 ohm speakers in parallel and you could hook up to 2 ohm output.
You can do a Series/Parallel and use 4 8 ohm speakers and amp will only see 8 ohms.

[rondom1]

Less ohms is better but as said everything has to match and handle each other. I for example have a CV 10.2 (2 ohm) instead of the 10.4 blah

[Stratmando]

I would find equipment and amp that I like, and buy speakers to match Impedance,
Or find speakers that I like, an find amp to match.
I know it doesn't answer your question. I have heard good 2's and good 8's?