The new sound reinforcement system was projected and installed by Adamson Europe’s Jochen Sommer, in cooperation with Dr.-Ing. Oliver Pabst and Dipl.-Ing. Kai Simanowski. It will be used as the primary sound projection source with an aircraft passenger cabin model. This experimental speaker rig will be used for studying the effects of noise emissions of the controversial propfan engines inside of the cabin, and the effectiveness of active noise cancelling measures. The B-118 subs are utilized to re-create a specific acoustic signature of the engine at realistic sound pressure levels.
A compact, powerful low frequency loudspeaker with a frequency range of 40- 400 Hz, with extended high pass characteristics was needed. Furthermore, the speaker had to be cost effective, as a greater number of units was needed in order to achieve increased flexibility in respect to pattern control through physical placement of each cabinet, and individual processing.
A decision was made for direct radiating single 18" cabinets from Adamson. The B118 is a classic Adamson design, employing a single AW18 driver, which has the as the World’s first 18" woven Kevlar diaphragm driver. With its extremely high stiffness to mass ratio, Kevlar virtually eliminates the effects of cone fatigue while providing enhanced long term reliability. Today the AW18 continues to be used in a variety of Adamson speakers, including as the LF extension in the very powerful Y18 cabinet, as well as in the SpekTrix Sub enclosure. The 16 units of B-118 subs are powered by two Lab.gruppen C48:4 amplifiers and controlled by a single Xilica XA-2040 processor.
After the jumpstart of their new engine, the members of Prof. Sachau’s department expressed a great deal of satisfaction. "The ADAMSON speakers met our specifications and demands in terms of output, reliability, and acoustic focusing. Further positive effects of the controlled low frequency radiation are greater energy efficiency, and reduced spill towards neighboring test rigs. Flexibility and control of this system offers new possibilities for our acoustic research projects." Dipl.-Ing. Kai Simanoswki concluded.