Table 2: Three models of AAC technology I, II, and III.

AAC technology
I model
AAC technology
II model
AAC technology
III model

(1) Usage of apparatus Mobile reflective plate apparatus Tunable perforated plate apparatusBoth mobile reflective plate and tunable plate apparatuses

(2) Mainly controllable acoustic impedance part of linerReactance part of acoustic impedance of linerResistance part of acoustic impedance of linerBoth reactance and resistance parts of acoustic impedance of liner