A portable isolation cabinet includes a body with a sidewall, a floor, and a positioning device. The sidewall is located on an edge of the floor. The positioning device is disposed on an interior face of the sidewall for removably securing a combination amplifier. The lid is pivotally connected to the body along one of its edges lid and an edge of the sidewall. The insulation is located on the interior face of the sidewall and is operable to absorb, and prevent reflection of, sound. The body and the lid are operable to close and thereby form an enclosed interior space. A focuser reflects sound emanating from the amplifier and directs it to a microphone.