Abstract: The present invention provides improved paving vehicles for following a supply truck for use in paving asphalt roadways. The paving vehicles of the present invention need not be transported on a trailer, and are capable of traveling at low or relatively high speeds on their own. This is accomplished through the use of novel chassis and propulsion systems having two rear axles, with each axle coupled directly to its own hydraulic motor, such that each of the two hydraulic motors provides power to one axle. Embodiments of the invention also include reciprocating conveyor apparatus and methods, such that the conveyor apparatus may be moved to a lowered position to receive the gravity discharge of materials from a hopper and supply truck during a paving operation, and moved to a raised position in order to provide a wide margin of ground clearance when driving the paving vehicle, or loading or unloading the paving vehicle from a trailer.

Abstract: The present invention provides improved paving vehicles for following a supply truck for use in paving asphalt roadways. The paving vehicles of the present invention need not be transported on a trailer, and are capable of traveling at low or relatively high speeds on their own. This is accomplished through the use of novel chassis and propulsion systems having two rear axles, with each axle coupled directly to its own hydraulic motor, such that each of the two hydraulic motors provides power to one axle. Embodiments of the invention also include reciprocating conveyor apparatus and methods, such that the conveyor apparatus may be moved to a lowered position to receive the gravity discharge of materials from a hopper and supply truck during a paving operation, and moved to a raised position in order to provide a wide margin of ground clearance when driving the paving vehicle, or loading or unloading the paving vehicle from a trailer.

Abstract: A phase plugs or acoustic lens improves the directional audio performance of a loudspeaker. Application of the improved directional audio performance to a sound system in a listening area may improve the performance of the audio system. Configuration of the acoustic lens or phase plug may include both symmetrical and asymmetrical features to provide an improved frequency response and directivity. The improved loudspeaker may provide improved an improved listing location, for example, in a vehicle.

Abstract: A phase plugs or acoustic lens improves the directional audio performance of a loudspeaker. Application of the improved directional audio performance to a sound system in a listening area may improve the performance of the audio system. Configuration of the acoustic lens or phase plug may include both symmetrical and asymmetrical features to provide an improved frequency response and directivity. The improved loudspeaker may provide improved an improved listing location, for example, in a vehicle.

Abstract: A phase plugs or acoustic lens improves the directional audio performance of a loudspeaker. Application of the improved directional audio performance to a sound system in a listening area may improve the performance of the audio system. Configuration of the acoustic lens or phase plug may include both symmetrical and asymmetrical features to provide an improved frequency response and directivity. The improved loudspeaker may provide improved an improved listing location, for example, in a vehicle.

Abstract: A phase plugs or acoustic lens improves the directional audio performance of a loudspeaker. Application of the improved directional audio performance to a sound system in a listening area may improve the performance of the audio system. Configuration of the acoustic lens or phase plug may include both symmetrical and asymmetrical features to provide an improved frequency response and directivity. The improved loudspeaker may provide improved an improved listing location, for example, in a vehicle.

Abstract: A phase plugs or acoustic lens improves the directional audio performance of a loudspeaker. Application of the improved directional audio performance to a sound system in a listening area may improve the performance of the audio system. Configuration of the acoustic lens or phase plug may include both symmetrical and asymmetrical features to provide an improved frequency response and directivity. The improved loudspeaker may provide improved an improved listing location, for example, in a vehicle.

Abstract: A phase plugs or acoustic lens improves the directional audio performance of a loudspeaker. Application of the improved directional audio performance to a sound system in a listening area may improve the performance of the audio system. Configuration of the acoustic lens or phase plug may include both symmetrical and asymmetrical features to provide an improved frequency response and directivity. The improved loudspeaker may provide improved an improved listing location, for example, in a vehicle.