Abstract: A new approach has been developed to combine mid-range and high frequency sound into the throat of a horn designed for sound reinforcement. An acoustic low pass filter element is interposed between the lower frequency passage and the higher frequency passage, so that a smooth combination of the two frequency bands is achieved at the entrance to the horn bell. Thus, each frequency band has nearly identical dispersion, and the two sources have equal delay.

Abstract: A new approach has been developed to combine mid-range and high frequency sound into the throat of a horn designed for sound reinforcement. An acoustic low pass filter element is interposed between the lower frequency passage and the higher frequency passage, so that a smooth combination of the two frequency bands is achieved at the entrance to the horn bell. Thus, each frequency band has nearly identical dispersion, and the two sources have equal delay.

Abstract: Circuitry is provided for simulating and emulating the sounds of a loudspeaker driven by a classic rock and roll guitar amplifier in the form of an electrical signal which, when input to a recording console or used to drive high fidelity headphones or a high quality monitor amplifier and monitor loudspeaker, accurately reproduces such sounds. The circuitry is incorporated at the output of a classic tube-type rock and roll guitar amplifier, and consists of three basic modules: a load impedance module (FIG. 3) designed to offer to the tube amplifier output a load impedance as a function of frequency (FIG. 1) which is modeled after and nearly identical (in both real and imaginary components) to the impedance of a classic rock and roll guitar speaker; a highpass filter circuit (24) which emulates the low frequency resonance and rolloff characteristics (FIG.

Abstract: The present invention relates to acoustic filters for use in combination with a multiple transducer system which includes a low frequency transducer subsystem and a high frequency transducer subsystem each mounted with respect to an axis directed towards the listening environment so as to function acoustically as though having coaxial acoustic centers. Preferably, the acoustic filter is constructed from one or more acoustical elements such as small tubes, narrow slits, perforated baffles, enclosed cavities, and the like combined so as to provide an acoustical impedance which is relatively low for the frequencies produced by the low frequency transducer but which is relatively high for the frequencies associated with the high frequency transducer.

Abstract: The present invention is an acoustic filter for use in combination with a coaxial loudspeaker system which includes a low frequency loudspeaker and a high frequency speaker which is axially aligned with the low frequency loudspeaker. The acoustic filter includes a pair of parallel, perforated sheets which are separated from each other a suitable distance and which are joined together at their peripheries in any appropriate manner so that they enclose an airspace therebetween in order to form a single section filter. The acoustic filter is disposed between the low frequency loudspeaker and the high frequency loudspeaker so the acoustic filter inhibits the high frequency sounds of the high frequency loudspeaker from interacting with the internal sidewall of the conically shaped diaphragm of the low frequency loudspeaker.