Abstract: The invention relates to a method for producing mass absorber systems, sound insulations having a great thermostable, noise-reducing effect, especially for the engine compartment of motor vehicles. Disclosed is a method for the direct backfoaming of absorber systems, the absorber of which comprises a foam layer (2) or fleece layer (4) with a one-sided or double-sided covering layer (3). Said method is characterized by the fact that the mass side of an absorber having a very low density is provided with a foam-impermeable covering layer (3), the absorber is placed in the foaming tool, and a certain pressure is generated in the absorber via the side located opposite the mass inside the closed foaming tool before the foaming process is triggered.