Abstract: A portable instrument amplification system includes a cabinet having a top cabinet member, a bottom cabinet member, and a plurality of side cabinet members. The portable instrument amplification system also includes at least one sealed chamber having a front chamber member, a side chamber member, a rear chamber member, at least one speaker driver, at least one side passive radiator, and at least one cabinet bracing secured in at least one corner of the sealed chamber. The cabinet bracing includes a cabinet bracing body, and at least one stiffener attached to the cabinet bracing body. The portable instrument amplification system also includes at least one front-facing port having a rear port member vertically attached between the side chamber member and a second side cabinet member behind the at least one side passive radiator, and a bass phase plug vertically disposed facing the at least one side passive radiator.