[akuan99]

I've finished replacing door speakers on my 228i and wanted to provide some information since there is very little information.
My plan is to replace all speakers (except center speaker) and HiFi amp with JL XD600 amp that I've removed from my old 128i.
The hardest part of this installation is removing door handle trim.
It is very hard to remove without breaking cheap plastic tab or leaving scars on the aluminum trim.
I must say that plastic used in current BMW cars is very cheap.
I even broke one speaker connector and connector latch for power window switch connector.
I used Morel Maximo speakers due to high efficiency and good bass response.
I purchased speaker adapters for F30.
The F30 base door speakers are same as F22 HiFi speakers.

Changing speakers only improved upper bass and midrange clarity significantly.
However the HiFi amp has strong equalization that affects upper midrange/low high and bass area so the resulting sound was a bit boomy and bright and edgy.
I set tone control to -4 clicks on treble and -1 on bass which helped a lot.
There was still a hint of midrange glare/edginess so I've decided to temporary disable center speaker by covering the speaker grill.
The sound imaging moved from just top steering wheel to lower left side.
I adjusted the balance control to boost the right side which moved imaging to just below center of steering wheel.
The sound quality at this point was really good, very wide with a nice clear and sweet midrange.
High was still a little edgy but it was likely due to heavy equalization boost from HiFi amp.
Maximum sound output was also reduced when eliminating center channel and adjusting balance control about 4-5 clicks to the right.
Next week I will replace Hi-Fi amp which will take care of sound high frequency edginess/glare and maximum output.

Here are some pictures of door speaker install. The rear speaker install is easy.