Large vehicles, such as sport utility vehicles (SUVs) and minivans, exhibit body boom phenomena during multiple source excitation events including rough road/impact and power-train induced events. The main cause of the boom is the low-frequency acoustic/vibroacoustic standing waves (modes) of the cabin cavity being excited via the high acoustic transfer functions at multiple paths, due […]
Read MoreAn active boom noise control solution which can be viewed as a low-frequency ‘active tuned acoustic damper’ is developed to add acoustic damping to the low-frequency standing waves inside the cabin of a large SUV to quiet its tonal persistent boom noise. The existing stock 8 inch subwoofer as well as one of the existing […]
Read MoreProblem: Most rooms/cabins have dimensions that favor standing waves (resonant modes) which are in the range of vibration frequencies of the propulsion engines, gensets, or other machinery on board watercraft. undesirable and unfortunate coupling of the room acoustic modes with the machinery vibration frequencies results in boom/rumble in the room. such low-frequency noise, which is […]
Read MoreThe use of a tuned damper or a dynamic absorber in time-varying systems can only be effective if they are adjustable (semi-active) and continuously returned to the current resonant frequency of the system. Such dampers require a tuning algorithm that can automatically adjust the adjustable parameter of the tuned damper/absorber, e.g., the stiffness of the […]
Read MoreIn many noise control applications, the offending noise occurs only in a narrow range of frequencies or even at a single frequency. Noise generated by industrial machines/equipment mostly falls in this category. For such situations, it is possible to design a sound absorption system that is “tuned” to those target frequencies. One of the most […]
Read MoreDEICON’s patented, feedback-controlled, electronic acoustic absorber is highly effective in reducing the boominess of sound at frequencies corresponding to offending (coloring) standing waves of an enclosed space. The controller which can be realized by a tunable, analog circuit or a high-speed micro-controller can be tuned to one or multiple low frequencies either to dampen the […]
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