The volume on the amplifier is at maximum and the volume from the speakers is still too low. What could the problem be?
If there are a large number of speakers in the system, the amplifier may not have enough output to provide adequate power to each speaker. In this case, additional amplifiers or a more powerful amplifier may be required. The speaker wiring should also be checked to ensure that there are no wires touching (at amplifier outputs, speaker selector, or volume controls).