Complex sentence: Poelzig put a great deal of thought into the acoustics of the rooms: the chairs in the large broadcasting room were specially designed so that seats had the same sound-absorbing qualities whether they were occupied or not.
Split into simpler sentences: Poelzig put a great deal of thought into the acoustics of the rooms. The chairs in the large broadcasting room were specially designed so that seats had the same sound-absorbing qualities whether they were occupied or not.