QuAuTiA4

does someone know what size speakers are in the front door of a bose a4 with a b5 body? i am gettting different speakers and need to know what size to order. thanks

matt13

but it was/is made by MB Quart. Many people have made their own adapters out of plywood or MDF.

MacSub

Yes, 4" components with 1" tweeter. The tweeter just slots in as long as it isn't bigger than 1".The mids will need an adapter as Matt says, regardless of size, as the Audi fitting uses a bizarre 3 point fixing that stands proud of the speaker aperture.
Just be wary of the depth restriction, which is about 60mm, so 5.25" speakers need to be slim models as the adapter eats up about 10mm.
If you're sticking with the Bose amp, then this s expecting 2ohm speakers all round, and most aftermarket units are 4 ohm. This shouldn't cause a problem but you'll find you'll get less volume from the front with 4 ohm units, which means driving them harder, so at loud volume could stress the Bose amp over time.