Hi Wayne, This is a bit of info I contributed on xdrivers, the speakers are probably readily available from your Supercheap stores.

" I did mine front and rear and the windscreen tweeters. The speakers need to be 160mm, which is NOT 6.5 inches. I used these,(Pioneer 6" Component Speakers TS-G1605C) which came with separate tweeters which I fitted one set in windscreen enclosures. (From Supercheap Auto) My X5 has no DSP, just a speaker in each door plus tweeters mentioned above. The factory tweeter is larger, I just packed some foam to raise the replacement. To be honest, I can't hear a mind blowing improvement, but it was worth the effort. The existing speakers are held in with some sticky double sided tape and pressed into the tubular enclosure, with some force and a large screwdriver as encouragement, they simply push out. I cut the wiring of the existing speakers then soldered short lengths from the new speakers to the plug mounted on the tubular enclosure. Pays to mark the polarity of the original as the plastic enclosures are not stamped + or -. I used a silicon based sealant to fix my speakers back into the tubular enclosure. Simple job, I got away with not removing door trim completely, just levered out the bottom to gain enough space to work. Tweeters are not fixed, just floating behind grill. The grill prises upwards from the cabin side, then flip upwards and out. "

Hope it is of some use if you decide to replace your speaker.

__________________
Neil

2016 X5 3.0D
2009 X3 3.0D
2005 X5 3.0 Diesel Sport (sold)
2007 320i (sold)