https://forums.quattroworld.com/a8/threads/7344.phtml

suggest the front woofers are only 4" but can take 5.25" with a bit of a trim.

surprisingly small if true

which would seem to backed up by this

https://www.audiworld.com/forums/a4-...-bose-2888688/

Yeah 4" is about right. They're pretty small but the ported enclosure makes a big difference. I left the Bose door speakers in place and upgraded everything else.

thanks Mk, if you've changed the rest could you confirm the sizes?

Well the front tweeters are exactly the same size as the dome on the Kenwood T-202 - probably about 40mm.

I don't know about the rear deck - those are now tuned ports for the two Infinity 12s using the boot as a 500 litre ported enclosure :D

I do have a full complement of speakers kicking about. Its just a case of remembering to measure them all :rolleyes:

10cm in the doors, but I'll personally be fitting 13cm in original enclosures. Deck is 6".

13cm in the original ported enclosures or direct on to the door card? I did think about printing an adapter to allow a larger speaker to be mounted to the door card, but thus far I haven't exceeded the capabilities of the original ported Bose units when backed up by a decent amp and subs.

That's the idea. Speakers I'm getting "should" fit inside the enclosure but time will tell.

13cm speakers in original enclosure +++

Nicely done :) Tested them yet?

Have you sealed the back so they use the ported enclosure or are they running 'free air'?