Friday, September 30, 5:00 pm — 6:30 pm (Rm 409B)
Joshua D. Reiss, Queen Mary University of London - London, UK
P17-1 Measuring Frequency and Amplitude Modulation Effects in Cross-Modulation Distortion from Audio Amplifiers—Ronald Quan, Ron Quan Designs - Cupertino, CA, USA
In the SMPTE IM (Intermodulation) distortion test using 60 Hz and 7000 Hz signals, it is normally assumed that the IM distortion products form amplitude modulation (AM) sidebands, which are commonly measured with an envelope AM detector. However, with other IM test signals the output of the AM detector is minimized or close to zero, while instead producing FM (Frequency Modulation) distortion. This paper investigates testing for phase and frequency modulation from cross-modulation and intermodulation distortions in audio amplifiers. The cross modulation test signal includes a 3 kHz tone and a high frequency amplitude modulation signal. Alternatively the test signal may include the 3 kHz signal and two high frequency tones. Amplifiers with feedback are tested.
Convention Paper 9654 (Purchase now)
P17-2 Finite Element Simulation of Ring Radiators with Acoustic Filter—Lakshmikanth Tipparaju, Samsung Research America - Valencia, CA, USA; Allan Devantier, Samsung Research America - Valencia, CA, USA; Andri Bezzola, Samsung Research America - Valencia, CA USA
Ring radiator loudspeakers consist of a phase plug in front of the diaphragm and are typically used to create omnidirectional sound. Potential resonances between the diaphragm and the phase plug create a design challenge and put additional requirements on the equalizer to obtain a flat amplitude response. We present a finite element model to predict and mitigate the undesirable peaks and dips in the amplitude response of ring radiator loudspeakers. Simulations show that a properly designed acoustic filter can minimize resonant behavior between diaphragm and phase plug. A maximum peak attenuation of 12 dB was obtained using this method. We observe good correlation between simulations and experimental results.
Convention Paper 9655 (Purchase now)
P17-3 Android Based Mobile Application for Home Audio—Visual Localization to Benefit Alzheimer Patients—“Remember It”—Raul Rincón Flórez, Universidad de San Buenaventura - Bogota, Cundinamarca, Colombia; Christopher Vottela Pérez; Esteban Polania Gutierrez; Luis Felipe Rios Zamudio
This article targets the development of a Mobile application to benefit people affected by Alzheimer's Disease implementing visual resources like RGB Leds, using Arduino as a medium between Android and these. On the other hand, the implementation of the program “App inventor,” the Arduino algorithm programming and the circuit mapping.
Convention Paper 9656 (Purchase now)