A modular, acoustic amplification apparatus, comprising: - a first module, including a first casing and an acoustic amplifier positioned inside the first casing, wherein the first casing has the shape of a parallelepiped having a first base and a first height, wherein the first base has a first long side and a first short side; - a second module including a second casing and a power supply or an accumulator positioned inside the second casing, wherein the second casing has the shape of a parallelepiped having a second base and a second height, wherein the second base has a second long side and a second short side; - a fastening enclosure, wherein the first casing and the second casing include respective fastening portions which can be placed at a position where they are aligned with each other to allow connecting the first module to the second module, wherein the length of the second long side of the second casing is equal to the length of the first short side of the first casing, and wherein the first module and the second module include respective electrical connectors (14a, 14b, 14c, 14d, 24a), configured to allow electrically connecting the first module and the second module to each other, wherein at least one electrical connector (14a, 14b, 14c, 14d) of the first module is located along the first short side and an electrical connector of the second module is located along the second long side, and wherein the dimensions of the first module and of the second module are selected to allow the first module and the second module to be installed in standard size racks, when assembled with the fastening enclosure. - a first module, including a first casing and an acoustic amplifier positioned inside the first casing, wherein the first casing has the shape of a parallelepiped having a first base and a first height, wherein the first base has a first long side and a first short side; - a second module including a second casing and a power supply or an accumulator positioned inside the second casing, wherein the second casing has the shape of a parallelepiped having a second base and a second height, wherein the second base has a second long side and a second short side; - a fastening enclosure, wherein the first casing and the second casing include respective fastening portions which can be placed at a position where they are aligned with each other to allow connecting the first module to the second module, wherein the length of the second long side of the second casing is equal to the length of the first short side of the first casing, and wherein the first module and the second module include respective electrical connectors (14a, 14b, 14c, 14d, 24a), configured to allow electrically connecting the first module and the second module to each other, wherein at least one electrical connector (14a, 14b, 14c, 14d) of the first module is located along the first short side and an electrical connector of the second module is located along the second long side, and wherein the dimensions of the first module and of the second module are selected to allow the first module and the second module to be installed in standard size racks, when assembled with the fastening enclosure.