Gigabyte.ga-m57sli-s4 no speaker

Hi everyone.
I am restoring a gigabyte.ga-m57sli-s4 board in a thermaltake_armor.lcs_ve2000 case.
connect (for testing) 2 sata and ide hard drives and install debian on ide, perfect.
now the problem ,, I have no audio.
If I connect headphones to the jack (it has 2), it can be heard through them.
The funny thing is that the board has beeps, when I start without ram or keyboard for example, and the system also makes beeps.
I have a manual for the board and connect the speak + and speak- cables, I think that in their place, but I cannot find any loudspeakers in the case or on the board, not even those black cylindrical ones that usually go on the plate.
do I need to put a speaker on it?