You need to wire them in Parallel (i.e. 1s3p pack).

Two unprotect will be wired to the JBL BMS board. I solder the black wire to the B+ and the red wire to the B-.

To keep the next replacement easier, I only connect the battery by twisting the color coded wires together and wrapping them with electrical tape.

One unprotected cell will be in the original battery compartment inside the cell holder (as shown) connect to one side of the BMS board.

Two cells will be inside the speaker compartment behind the Bass Radiator. The unprotected one (right hand side radiator) will connect directly to the BMS board.

The protected one (after I open and rearrange the PCB of the battery for a better fit into the speaker compartment) will connect parallel to the protected one from other side of the bass radiator.