Hi, if you want to listen to quality sound, then you need to buy all new speakers.
I recommend buying a set of amplifier + speakers from harman kardon. Clear sound, speakers at maximum volume does not roar, or buy top hi-fi. You also need to have a quality stereo, to process and produce good sound. I helped my friend install my car radio in X5 and he also bought speakers from harman kardon, the whole kit cost him $2000 at a discount. I found a car radio for a BMW X5 series E70 / X6 series E71 (2011-2013)
https://smarty-trend.com/bmw-x5-x6-s...head-unit.html like this. It is not cheap, but also not so expensive to buy the original which is installed from the manufacturer.