A novel design of two-way multimedia loudspeaker
A multimedia loudspeaker usually stands on a desk, so the reflected sound from the desk interferes with the direct sound from the loudspeaker. Reflected sound from the desk must be taken into consideration in the designing process in order to obtain the flattest possible resultant frequency response in the listening position. This paper introduces a novel design of a two-way multimedia loudspeaker, which gives flat frequency response at broad range of distances from the listener.
Loudspeaker fault detection using Artificial Neural Network
Traditionally, loudspeaker's quality control has been done manually and inspection of loudspeaker faults is time consuming and causes error in the quality evaluation. In order to reduce the time consumption and errors in the quality evaluation, in this research work, a simple loudspeaker diagnosing system is developed based on the harmonic distortion. The faulty and normal loudspeakers are tested using the sound emanated from the loudspeaker in the frequency range between 20 Hz and 20,000 Hz. A fast Fourier transform (FFT) is applied on the recorded signal to transform from time domain to frequency domain and the frequency spectrum is obtained. From the frequency spectrum, first six frequency band and it corresponds the total energy are computed and chosen for further analysis. The total energy of the each frequency band signal are obtained and used as features for training the neural network. A simple neural network model is developed for the automatic detection of loudspeaker faults. From the result it is observed that the proposed method is able to classify the faults with an accuracy level of 84%.
A slowly rotating coil system for AC field measurements of Fermilab Booster correctors
A method for measurement of rapidly changing magnetic fields has been developed and applied to the testing of new room temperature corrector packages designed for the Fermilab Booster Synchrotron. The method is based on fast digitization of a slowly rotating tangential coil probe, with analysis combining the measured coil voltages across a set of successive magnet current cycles. This paper presents results on the field quality measured for the normal and skew dipole, quadrupole, and sextupole elements in several of these corrector packages.