Abstract: Methods and apparatus are disclosed that achieve sub-harmonic signal processing, stereo-width expansion, sub-woofer signal processing, and tube distortion emulation to achieve various desirable acoustic effects when used to modify an input signal containing, for example, music content.

Abstract: Methods and apparatus may provide for one or more of: receiving an input signal containing frequencies from among a first range; filtering the input signal to produce a first intermediate signal containing frequencies from among a second range; producing a sub-harmonic signal from the first intermediate signal containing frequencies from among a third range, the third range of frequencies being about one octave below the second range of frequencies; canceling energy at at least some frequencies from among a fourth range of frequencies from a left channel signal of the input signal to produce at least a portion of a left channel output signal; and canceling energy at at least some frequencies from among a fifth range of frequencies from a right channel signal of the input signal to produce at least a portion of a right channel output signal.

Abstract: Methods and apparatus are disclosed that achieve sub-harmonic signal processing, stereo-width expansion, sub-woofer signal processing, and tube distortion emulation to achieve various desirable acoustic effects when used to modify an input signal containing, for example, music content.

Abstract: A sub-harmonic generator includes: an input filter operable to receive an input signal containing frequencies from among a first range and to produce a first intermediate signal containing frequencies from among a second range; a signal divider circuit operable to receive the first intermediate signal and to produce a square wave signal containing square wave signal components at fundamental frequencies from among a third range, the third range of frequencies being about one octave below the second range of frequencies; a wave-shaping circuit operable to receive the square wave signal and to produce a second intermediate signal containing sinusoidal signal components from among frequencies corresponding to the respective fundamental frequencies of the square wave signal components; an RMS detector operable to produce an RMS signal corresponding to an instantaneous amplitude of the first intermediate signal; and a voltage controlled amplifier operable to amplify the second intermediate signal by an amount prop

Abstract: Methods and apparatus are disclosed that achieve sub-harmonic signal processing, stereo-width expansion, sub-woofer signal processing, and tube distortion emulation to achieve various desirable acoustic effects when used to modify an input signal containing, for example, music content.

Abstract: An apparatus and method for modeling an acoustic sound in an electric stringed musical instrument is provided. A preferred embodiment, among others, includes a bridge sensor configured to sensing string vibrations at the bridge of the instrument so that a bridge signal is generated in accordance with the vibrating strings. A body sensor, which may be positioned at different points on or within the body of the instrument, senses the resonance of the string vibrations. The body sensor generates a body resonance signal in accordance with the sensed resonance. An amplification circuit amplifies the body resonance signal when the amplitude of bridge signal exceeds a first predetermined level. In addition, a second amplification circuit amplifies the bridge signal. A summing circuit adds the amplified body resonance signal with the amplified bridge signal to produce an output signal that, when replicated in sound, models the sound of an acoustic instrument.