Abstract: A system and method for providing microphonic isolation on a transmission line. The transmission line has a first part and a second part. The first part of transmission line carries a data signal and a microphonic signal. The microphonic signal has frequencies that include those in a range of substantially 20 Hz to substantially 20 kHz. The system includes an isolation apparatus. The isolation apparatus has an input in electrical communication with a first part of the transmission line, an output in electrical communication with the second part of the transmission line, and a filter in electrical communication with the input and the output. The filter is arranged to substantially remove the microphonic signal received at the input from first part of transmission line and pass the data signal to the output.

Abstract: A low-powered loud speaker is provided with one or more echo generators composed of an insulation tube, a first magnetic permeability element, a second magnetic permeability element, and an induction coil wound around the insulation tube. The first and the second magnetic permeability elements are engaged with the insulation tube such that the first magnetic permeability element is suspended, and that the second magnetic permeability element is induced to generate a magnetic attraction at such time when a sound frequency current passes the echo generator. The echo generator is thus capable of vibration twice the sound frequency, so as to simulate the echo effects.

Abstract: The audio process is a signal path having a plurality of filters connected or including distortion means. The prime example of this phenomenon surrounds inductances such as found in magnetic tape recorders, spring reverberators, and transformers. The inductors require a pre-emphasis filter to produce a constant current. Secondarily there are the complementary filters associated with the average spectrum of audio which are used to maximize the signal to noise ratio. Ideally the net response of the filters is flat, however, roll-offs at the audio extremes are quite common.The audio process distortion emulates the distortion of the active devices between the filters such as vacuum tube and magnet non-linearities. Since the distortion devices follow filters, the spectra of distortion is different than the frequency response.

Abstract: A method of determining the physical location of undesired resonance zones induced by acoustic feedback in a spring reverberation unit and damping the vibration of these resonance zones. The improved spring reverberation unit with damping material located at the resonance points of the unit produces a reverberated audio signal which is substantially free from the screeching and howling caused by acoustic feedback.

Abstract: A reverberation apparatus includes a signal input terminal to be supplied with an input signal, an operational amplifier having an inverted input terminal, a non-inverted input terminal, and an output terminal. The inverted input terminal is connected to the signal input terminal through an input impedance circuit. The non-inverted input terminal is connected to a reference point, and the output terminal is connected to the reference point through an inductance circuit as a load and a first impedance circuit. A second impedance circuit is connected between the inverted input terminal of the operational amplifier and the connection point between the inductance circuit and the first impedance circuit. In this circuit, the inductance circuit functions as a drive circuit of the reverberation apparatus.