I was so tired of stock audio system in Bmw. Bmw should have better speaker in his cars.
I already replaced headunit with 2 din unit. Now it was time to upgrade door speakers.
I bought cheap renegade rx 42 4 inch, 10 cm speakers.They costed me 20 eur.
http://www.onlinecarstereo.com/CarAudio/assets/ImageGen/Medium/Renegade_RX42.jpg
You can check more specs here: http://www.carid.com/renegade/4-2-way-coaxial-120w-speakers-mpn-rx42.html#applications
I was a bit gredy so I wanted to install the strongest speakers. That made my install a little bit difficult. Problem is mounting depth, because it is aprox 52 mm and stock is 48 mm. So I had to remove plastic magnet cover.
Door panel is relatively easy to remove. You remove trim and under it you will find torx screw, one is located under the airbag sign and one under arm rest.
https://farm1.staticflickr.com/570/22946808480_50bf30732d_c.jpg
You don’t need to remove trim from door, you can just simply put it on a chair or box. Please be carefull with airbag. If you want to completlly remove the trim, disconnect the battery first.
https://farm1.staticflickr.com/578/23242641565_5ec1394a79_z.jpg
https://farm2.staticflickr.com/1525/24794807802_e8fa9c9ce9_c.jpg
https://farm6.staticflickr.com/5785/22848486667_a6c6aa026a_c.jpg
As you will see bmw speaker has only 3 screws. Another stupid thing from german engineering, they just want more money! But don’t worry, just screw top 2 screws and use big washer on third and speaker won’t go anywhere.
https://farm6.staticflickr.com/5639/22614187554_8f8e793a75_c.jpg
https://farm2.staticflickr.com/1719/24285874053_ffac63fd59_z.jpg
https://farm2.staticflickr.com/1605/24912756345_2535918927_c.jpg
Cut original connector aprox 2 cm from connector so you can solder back it, if you would like to install your old speakers back in the car.
I noticed much better sound quality and better frequency range. It would be much better if I would install amplifier or I will also replace headunits power cable with new cable.