Heathkit US-3

Documentation on the Heathkit US-3 is thin. What survives comes almost entirely from a single period notice. High Fidelity (February 1960, p.95) described it as a utility-grade coaxial speaker kit with a 12-inch woofer and a 3-inch tweeter, and a built-in crossover network set at 2,000 cycles. Frequency response was given as 50 to 15,000 cycles. The speaker was rated to handle a full 15 watts. The kit included instructions for building a recommended bass-reflex enclosure, and it could be adapted for other cabinet designs if the builder preferred.

The US-3 seems to have been a straightforward, no-frills project - aimed at the hobbyist who wanted a capable speaker without paying for a prebuilt cabinet. The same issues of High Fidelity that carry the US-3 mention also heavily advertise Heathkit's AS-2 speaker system (a licensed design with preassembled cabinets). That suggests the US-3 sat in a more budget-oriented, build-it-yourself niche alongside that flagship model. No catalog pages, kit manuals, or production dates for the US-3 have surfaced in the archival record. The brief review notice is essentially all that is known.

Type: coaxial speaker kit (12″ woofer + 3″ tweeter)
Crossover: 2,000 Hz
Frequency response: 50–15,000 Hz
Power handling: 15 watts
Enclosure: bass-reflex (building instructions included)