Like many others, I did not want to drop the $600 for the Bavsound Stage One upgrade. So I scoured eBay for Logic 7 OEM fit speakers that might work. I ended up with a set of used Logic 7 speakers from an E90 for 250 bucks. The midrange speakers and the door tweeters were an exact fit. All the connectors were factory, so no cutting of wires was required.
i replaced the mid's all around and the front door tweeters without any mods. The Bavsound YouTube video has step by step instructions on how to replace speakers all around:
The front dash and rear deck tweeters required removing the old tweeters from the mounts and gluing the new tweeters in. They are an exact fit into the mounts so no issues. I bought the following on eBay:
3 Deck/Dashmount Mids and 3 Deck/Dashmount Tweeters
2 Door Mids and 2 Door Tweeter
The sound difference is amazing. Lot more depth and bass punch and the speakers can handle much more volume without losing clarity. As my dad always said "Good speakers can make an average amp sound really good." Boy was he right.
All in all about a four hour job, with the doors taking 2 hours of that.