Bmw Z4 Sdrive23i Speaker Upgrade/replacement Options

[Metasyntactic]

Hello All,

One of my speakers has popped after an accident (not my
fault!) and id like to replace it.

However, speaking to my local BMW, they don’t stock
replacement speakers let alone upgrades for my model.

Back in TT days, I upgraded the sound system to the Bose
Opera –something or other. It was amazing!

I'm looking to do the same with this one. I'm not
technical in the slightest, so don’t know what you’d refer to the speakers
behind the seats as (the two big main ones).

But id like them to be something meaty/tasty that can
carry the base.

Not sure if ill need/want to upgrade the door card

speakers – but can anyone give any recommendation for;

a) The speaker that I should install (style, size, brand,

spec, price)

b) What I should be looking to pay a local specialist to

install the two behind-the-seat speakers

c) If theres a genuine/recommended BMW upgrade/brand

style speaker.

d) [Optional] a recommended fitter/installer/supplier in
the Northamptonshire area.

Many thanks in advance everyone!