I am not totally positive but I think both the Matrix 801 and 802 series 2 both had the IPOC circuitry..From what I can remember the biggest improvement ( in stock form ) in the Series 3 came from the removal of the IPOC circuit..I think they removed the IPOC in the Anniversary Edition which was in between the Series 2 and 3....
B&W also may have made a change in the bass drivers in the Series 3 802.. Check with B&W for the IPOC info to find out for sure.......You may also find out that most Matrix 801 and 802 owners thought the B&W bass alignment filter was garbage..I tried it once and removed it and found they sounded much better without the B&W filter..( my taste anyways ) ....
B&W also may have made a change in the bass drivers in the Series 3 802.. Check with B&W for the IPOC info to find out for sure.......You may also find out that most Matrix 801 and 802 owners thought the B&W bass alignment filter was garbage..I tried it once and removed it and found they sounded much better without the B&W filter..( my taste anyways ) ....