It used standard 8 track tapes, but run at high speed for higher fidelity. The two ohm idea was a way to get around the rise in impedance near speaker resonance, which reduces the power output considerably. The design used two cabinets; one open back, with four 8-Ohm 12's, wired in parallel to produce a nominal 2 Ohm load (in an open back cabinet).
The second cabinet was a ported box, with two 8-Ohm 12's, wired for 4 Ohms. When run in parallel, the two boxes produced a constant 1.8 Ohm load to the amp, regardless of frequency. As one box impedance started to rise, it was shunted by the other box to hold the impedance steady.
It was actually a rather ingenious solution at the time.