Attack transients of free reed organ pipes
Jonas Braasch, Christian Ahrens · The Journal of the Acoustical Society of America · 1999
Free reed pipes in organs have fallen out of favor, because they were reputated to have a sluggish attack transient. To test this theory, the starting transients of the ‘‘Klarinette 8 ft’’ pipes were measured on the new Klais organ in the Auditorium Maximum, Bochum. Further measurements to determine the role of the wind pressure were done on the wind chest of the Klais workshop in Bonn. The transients of the free reed pipes were compared to those of bound reed pipes and diapason pipes (measured on the same organ). As the results show, the attack transient of the free reed pipes was indeed slower than that of bound reed pipes, but on the same order of that of diapason pipes. However, in contrast to the free reed pipes, diapason pipes have a noticeable broadband noise preceding the sound. In addition, there is a delay between the onset of the first-order harmonic and the onset of the higher-order harmonic in the starting transient of the free reed pipe. This effect is not usually found in the transient of diapason pipes.