The measuring box was supplied with a very high sound pressure level reduction of Dw= 51 dB and a low-reflection inner lining – suitable for acoustic measurements at a lower measuring frequency of 250 Hz. The G+H SONEX®K panel system and the G+H SONEX®WF flat absorbers were used here. Due to confined space conditions at changing locations (transport via lifts, through doors, etc.), the measurement box had to be designed in two parts, while at the same time offering the possibility of simple assembly into a functioning compact unit. Hydraulic aggregates are measured in the measuring box. For this purpose, it was necessary to integrate 20 hydraulic connections of different diameters in the walls and to make the inner trough of the box watertight. The final acoustic measurements took place in the new laboratories of the Acoustic Competence Centre in Maxdorf.