B2 Audio BM402C Owner's Manual page 6

Installation
7. The below illustration shows the comparison of factory speaker(left) and
B2 audio upgrade 4" speaker, B2 audio mid-range speaker uses a cast
aluminum chassis, powerful yet tiny neodymium magnet.
8. Replace the original mid-range speaker with B2 audio mid-range speaker,
using the original bolts. Once the speaker mounting is done, reconnect
the speaker wire and the provided crossover network&inline crossover.
Then you have to fix the crossover network to the door panel (by using
the double adhesive tape which is already attached on the crossover
network or cable ties)
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