Abstract: The system allows for distribution of 70 Volt high-voltage audio underground in direct burial cable or conduit. From the converter box the audio wires will be coming out of the earth at a safe 8 ohms (minimized shock risk). Typically the size (power output) of the amplifier alone limits how many 70 V converter boxes can have daisy chained together.

Abstract: A multiple speaker array for audio systems. The array comprises multiple range 30 to 40 ohm speakers connected in parallel. The number of speakers are selected to maintain the load on the system amplifier within an acceptable range, usually 1 to 8 ohms. The array may also include a low range speaker such as an 8 ohm sub-woofer. The speaker array “kit” may be used indoors or outdoors and allows the user to distribute an array of speakers and sub woofer over an area to achieve balanced coverage using conventional amplifiers.

Abstract: A multiple speaker array for audio systems. The array comprises multiple range 30 to 40 ohm speakers connected in parallel. The number of speakers are selected to maintain the load on the system amplifier within an acceptable range, usually 1 to 8 ohms. The array may also include a low range speaker such as an 8 ohm sub-woofer. The speaker array “kit” may be used indoors or outdoors and allows the user to distribute an array of speakers and sub woofer over an area to achieve balanced coverage using conventional amplifiers.

Abstract: A sub woofer for in-ground installation and a method of installation. The sub woofer has a cylindrical enclosure or housing having a driver, electronics and a band pass filter. The driver cone is coaxial with the axis of the cylindrical housing. A port tube assembly having a tuned port tube and a resilient elbow interface is attached to an end wall of the housing in an eccentric position with the port tube projecting vertically and terminating at a canopy. The installation requires placing the enclosure in an excavation and positioning the housing and port assembly so a predetermined above ground spacing exists between the upper end of the above ground port tube and grade.

Abstract: An audio frequency distribution and adjusting circuit includes a variable resistor network having a first variable resistance and a second variable resistance coupled in series between a first resistor network terminal and a second resistor network terminal. The variable resistor network also includes a wiper contact with the first variable resistance and the second variable resistance for adjusting the total resistance between the resistive network terminals. The variable resistor network terminals are coupled in parallel with a low-pass filter, which is coupled to a low-frequency driver. The resistor network wiper contact is electrically coupled to the input of the high-pass filter, which is coupled to a high-frequency driver.

Abstract: A speaker apparatus comprises an enclosure including a front panel and having a sealed compartment and a ported compartment. A first driver is mounted in the front panel and within the sealed compartment. An internal passive radiator is mounted in the enclosure. A radial port is formed in the enclosure front panel and is disposed at a position facing the internal passive radiator. The speaker apparatus also includes a second driver mounted in the front panel and within the sealed compartment. The internal passive radiator is mounted between the first and the second drivers.