I have enjoyed the privilege of working with the wonderful Freiraum agency since 2007. During this time, they have not only positioned themselves as one of the first German providers of acoustic solutions, but also as the best (I may be a tiny bit biased, but the feedback from clients speaks for itself).
This link leads to the Freiraum Akustik website (in German). There you will not only find beautiful art that improve room acoustics, but also first-class and competent advice. All my photos are available as acoustic pictures, even if they are not currently on the Freiraum website.