Compaq 247320-003 - Deskpro 4000 - 5166 Model 2500/CDS Reference Manual page 105

To install an optional speaker in the expansion board cage,
complete the following steps:
1. Remove the expansion board cage from the computer
chassis.
2. Slide the speaker under the metal tabs on the expansion
board cage.
3. Secure the speaker by inserting the screw in the top screw
hole, as indicated in the illustration below.
4. Connect the speaker wires to the riser board, as indicated in
the illustration below.