rawky

What are the sizes for all of the speakers and subwoofers in a 1991 S4?

atb

Tweets in the doors and rear quarters I think are 1.5".
The mids in the doors and the hatch are 4's.
The bass speakers in the rear quarters I believe are 6's..

No subs in the 928.

dr bob

The rear quarter speakers are a bit bigger than a standard 6", and sit in a molded shell contoured to the B-pillar shape. It takes a bit of work with the saw and the Dremel to cut out the old support structure and glue in a new speaker. It would be very optimistic to describe this speaker as anything better than a low midrange. There is no appreciable bass available because the speaker sits in a non-existent 'enclosure'. So think about havinge tweeters in the doors and the rear quarters, 4" high-mids in the doors and rear quarters, and a couple 6" mids in the B-pillar.

If you want the really low musical rumble, get an RMB and leave the radio off.