Tri-Amping - A technique commonly used in large-scale sound amplification for concerts, Tri-amping is the practice of connecting three audio amplifiers to a loudspeaker unit: one to power the bass driver (woofer), one to power the mid-range and the third to power the treble driver (tweeter).

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The Think Outside Boomtube H2O1 will have specs on par with the Virgin Boomtube EX, including 40 watts of power, MaxBass bass-boosting circuitry, and an integrated subwoofer.

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The dock features reinforced bass through a passive radiator and high power amplification for powerful full digital sound.

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The front of controller features bass, treble and volume knobs, a power toggle, LED indicator and a 3.5mm auxiliary jack, while the back features a secondary 3.5mm jack, a powered USB port (allowing for the hookup of Bluetooth-enabling dongles, for example) and a toaster slot for the current and previous generation of AirPort Express routers.

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It features an analog power switch and controls for volume, bass and treble.

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Calling itself Peter Bjorn and John, the trio began experimenting with its format: Keyboardist Yttling switched to bass, while the band as a whole refined its catchy power-pop sound.

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In practical terms, a power purchase agreement differs little from a lease, according to Jonathan Bass, a SolarCity spokesman.

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