Sound system: Basic Vs Premium

[Land_Shark]

Hi,

Got a quick question...
The basic sound system (idrive included) in the Z4 has only 6 speakers (FT left/right, RR left/right/ and 2 small FT subwoofers) No amps, correct?
The premium comes in 2 options, amps 350W or 650W with 14 speakers (FT left/right, FT left/right tweeters, middle speaker behind the idrive screen, RR left/right behind the seats, RR left/right sides close to the doors, FT left/right subwoofers, 1 RR large subwoofer, 2 subwoofers under the seats???

And... In the basic sound system, can you have more speakers but not have the amps?? If I am not mistaken, I have on my Z 9 speakers (FT left/right, RR left/right/ and 2 small FT subwoofers, middle speaker behind the idrive, FT left/right tweeters and no amps. I am mistaken, correct?
PS: within the idrive setup, I have 7 band equalizer... Is this still for the basic sound system?

I am looking into upgrading, but before I start opening every speaker/mounting cover.. Thought I ask first on this very helpful forum..
Thanks!