An assembly for treating subcutaneous tissues using acoustic waves in the range of low acoustic pressure ultrasound waves is disclosed. The assembly comprises an acoustic wave generator and transducer for the generation and transmission of unfocused acoustic waves, a source of microbubble solution and solution injection members for percutaneously injecting the solution at a treatment area between 1 mm and 5 mm below the dermis. The assembly is useful for treatment of subcutaneous abnormalities including cellulite, lipomas and tumors.