A speaker, comprising: a casing comprising an opening end (1 10a) at an upper end thereof and an upper rim at the upper end, said casing defining an axial direction; a speaker unit disposed in the casing, a predetermined distance in the axial direction being formed between a top surface of the speaker unit and the upper rim of the casing; and a sound guiding assembly comprising a reflecting surface facing the speaker unit, wherein the speaker unit is adapted to transmit a sound wave to the reflecting surface in the axial direction, and the reflecting surface is inclined toward the axial direction and adapted to reflect the sound wave such that the sound wave is transmitted in a second direction different to the axial direction; wherein the casing comprises at least one first connecting portion (1 10c) provided at the opening end, and the sound guiding assembly comprises at least one second connecting portion; wherein the sound guiding assembly comprises a frame and a sound guiding assembly body, the at least one second connecting portion is connected to the frame, the frame limits the sound guiding assembly body within the casing, and each second connecting portion structurally interferes with a corresponding first connecting portion such that the sound guiding assembly is detachably assembled to the opening end of the casing while being fully accommodated inside the casing; wherein the at least one second connecting portion comprises at least one engaging slot, and the at least one first connecting portion comprises at least one engaging block adapted to move into the at least one engaging slot with rotation of the frame relative to the casing. a casing comprising an opening end (1 10a) at an upper end thereof and an upper rim at the upper end, said casing defining an axial direction; a speaker unit disposed in the casing, a predetermined distance in the axial direction being formed between a top surface of the speaker unit and the upper rim of the casing; and a sound guiding assembly comprising a reflecting surface facing the speaker unit, wherein the speaker unit is adapted to transmit a sound wave to the reflecting surface in the axial direction, and the reflecting surface is inclined toward the axial direction and adapted to reflect the sound wave such that the sound wave is transmitted in a second direction different to the axial direction; wherein the casing comprises at least one first connecting portion (1 10c) provided at the opening end, and the sound guiding assembly comprises at least one second connecting portion; wherein the sound guiding assembly comprises a frame and a sound guiding assembly body, the at least one second connecting portion is connected to the frame, the frame limits the sound guiding assembly body within the casing, and each second connecting portion structurally interferes with a corresponding first connecting portion such that the sound guiding assembly is detachably assembled to the opening end of the casing while being fully accommodated inside the casing; wherein the at least one second connecting portion comprises at least one engaging slot, and the at least one first connecting portion comprises at least one engaging block adapted to move into the at least one engaging slot with rotation of the frame relative to the casing.