At the behest of the Trox company, the Fraunhofer Institut für Bauphysik (IBP; “Fraunhofer Construction Engineering Institute”) has conducted laboratory tests of the sound absorption properties of 1000 mm and 1500 mm MKA200 acoustic splitter attenuators. The results of the tests not only confirm the accuracy of the data in the Trox catalogue: they also show that for the 500 Hz frequency range, the sound absorption values are higher than those indicated in the catalogue. This came in the wake of publication of the results of tests of Trox acoustic splitter attenuators on the news Web site of RAL Gütegemeinschaft Schalldämpfer e.V., which had previously sent a set of MKA200 acoustic splitter attenuators to IBP for testing. The sound absorption values measured were up to 10 decibels lower (250 Hz) than those indicated in our catalogue. Understandably, publication of these results caused consternation among our customers. However, extensive tests performed in the Trox laboratory have demonstrated that the values measured by RAL-Gütegemeinschaft e.V resulted from the fact that the splitter modules were incorrectly mounted in the test stand (owing to the disposition of the Lambda plates). In March 2002, we asked RAL-Gütegemeinschaft Schalldämpfer e.V. to publish the correct data on their Web site as soon as possible. The values recorded by IBP (which were 500 Hz better than our own) will be included in future Trox catalogues and product selection programs. Verification by IBP of our published technical data will strengthen our customers’ faith in our technology and will enable architects to plan and realize room air conditioning systems secure in the knowledge that our data is reliable.