Just to share my experience with E89s speakers. Having owned one with Basic, and the last two with Premium, they all rattle and distort notes at reasonably higher volumes (my benchmark for measuring this was listening to Intro by The XX -- excellent at accentuating those demanding notes.) With my 2nd E89 with Premium Audio, I went to a reputable auto audio store in the city and was told that I pretty much had to upgrade the amp as well as the speakers to stop experiencing the rattling and distortion at higher volumes. He was surprised, however, to find that E89s came with a 3 way component speakers btw.... he thought it was an overkill for such a tiny cabin (he shared than even the Ferrari 458 he worked on earlier had a 2 way front component system, although I believe that's irrelevant since the notes come from the engine if that's your vehicle
Adding an 8 channel JBL amp as well as upgrading the front 3 way components (6 speakers in total) plus installation yielded a whopping $2700. I also had him add sound deadening which was very effective at reducing outside noise. After the speakers break-in period of 48 hours of playtime, fidelity improved a bit, but, more importantly, rattling and distortion disappeared completely at higher volumes.