Abstract: Complimentary series crossover circuits to reduce phase distortion in loudspeaker groups, typically pairs, are described. In the fundamental embodiment, each loudspeaker possesses two drivers, a woofer and a tweeter. The “effective third-order” crossover on the right-hand loudspeaker remains “symmetric,” but the “effective third-order” crossover on the left-hand loudspeaker is rendered “asymmetric,” as described. Other embodiments apply this principle to higher crossover orders and greater numbers of drivers. This technology is applied to the series filter in 2.5-way, 3.5-way, etc. loudspeakers using otherwise conventional series/parallel crossovers. This technology can be combined with other circuits like a Zobel, typically used for impedance correction. Some configurations of “phase-unified” loudspeakers require that a Zobel is applied to all drivers except the tweeter. Accordingly a rule combining effective crossover order and handedness is established.

Abstract: Complimentary crossovers that reduce phase distortion in loudspeaker systems, typically pairs, are described. In the fundamental embodiment, each loudspeaker possesses two drivers, a woofer and a tweeter. The “effective third-order” crossover on the right-hand loudspeaker remains “symmetric,” but the “effective third-order” crossover on the left-hand loudspeaker is rendered “asymmetric,” as described. Other embodiments apply this principle to other crossover orders and/or greater numbers of drivers. This technology can be combined with other circuits like a Zobel, typically used for impedance correction. Some configurations of “phase-unified” loudspeakers require that a Zobel is applied to all drivers except the tweeter. Accordingly a rule combining effective crossover order and handedness is established.

Abstract: Complimentary crossovers that reduce phase distortion in loudspeaker systems, typically pairs, are described. In the fundamental embodiment, each loudspeaker possesses two drivers, a woofer and a tweeter. The “effective third-order” crossover on the right-hand loudspeaker remains “symmetric,” but the “effective third-order” crossover on the left-hand loudspeaker is rendered “asymmetric,” as described. Other embodiments apply this principle to higher crossover orders and greater numbers of drivers. This technology can be combined with other circuits like a Zobel, typically used for impedance correction. Some configurations of “phase-unified” loudspeakers require that a Zobel is applied to all drivers except the tweeter. Accordingly a rule combining effective crossover order and handedness is established.

Abstract: A compact high acoustic power loudspeaker system includes an enclosure in which at least one low frequency speaker device and a bass-reflex port are provided. The bass-reflex port is mounted on the enclosure in a semiflexible manner such that the port can vibrate to provide additional bass reinforcement as compared to prior art loudspeakers. The bass-reflex port broadens the frequency response of the port and is less subject to “one-note bass” as compared to prior art ported systems.

Abstract: A multichannel imaging spectrometer for low speed, low altitude airborne geological, geophysical and environmental surveys, particularly adapted to provide detector limited noise threshold. An optical scanner employs a rotating polygon allowing reduced scan optics with increased data acquisition efficiency. Scan speeds from 5 to 50 scan/sec with up to 2048 pixels per scan are available. Multiple spectrometers integrally registered allow channelization of the received signal to optimize noise performance in the range from ultraviolet through infrared. Output data is in a form for recording and real time display. All channels are acquired simultaneously resulting in perfect band-to-band registration with continuous spectral curves for each pixel.