Advent Corporation

Around 1968, Kloss quit KLH to develop a low-cost projection television, but had trouble financing the leading-edge research and development that was still required. To earn some money, he decided to build a high-performance low-cost dual driver speaker system with 10-inch (25 cm) woofer called simply The Advent Loudspeaker (later given the retronym the Larger Advent, after introduction of The Smaller Advent Loudspeaker). It rivaled the sound of the then top-line AR Model 3a (which used three drivers and a 12-inch (30 cm) woofer), but only cost about half as much.

Advent produced a number of different versions of the 2-way Advent, including the Advent Loudspeaker, the Smaller Advent Loudspeaker, the "New" Advent Loudspeaker, Advent/2, Advent/3, 4000 series, and 5000 series, to name a few. They were usually offered in both wood veneer and vinyl-covered "utility" cabinet versions, which other than appearance were acoustically identical.

The popularity of the Advent Loudspeaker overshadowed any other Advent products, even the eventually released first video projector for home, Advent VideoBeam 1000.

Kloss then resumed work on increasing the fidelity of cassette tapes, a format that had originally been developed to be used only for voice dictation. The original Advent 200 model, launched in 1970, had exhibited mechanical problems and was quickly replaced by Advent 201 in 1971, incorporating Dolby B noise reduction (for both recording and playback), along with chromium dioxide tape in the first popular high fidelity cassette deck. Advent 201 was a "game changer":Stereo Review had found that it can successfully compete against more expensive reel-to-reel decks. Commercially it was not as successful as the loudspeakers were, but was manufactured for few years.