The Jubilee's frequency response (fig.1) was better than that of the older Decca designs. The omnipresent bass wiggles were now confined to a gentle rise toward 20Hz. Likewise, the 250Hz region was uniformly flat. There was just the gentlest of downward tilts, 0.5–0.75dB, from 100Hz to 5kHz. While the range above 5kHz was mildly perturbed (+1dB, –3.5dB), matters roughly balanced out over the final octave. Significant high-frequency resonances were held off until 24kHz.
Fig.1 London Jubilee, outer-band frequency response and channel separation…