Eton, ER-4 – based on the Heil Air Motion transformer.
This is one of the best sounding ribbons we’ve heard. Another benefit is the low crossover point capability.
Imp – 4 ohm
SPL – 88dB
Fs – 490Hz
Flange 110 x 110mm
Cut-out 90 x 90mm
Di-pole or requires a sealed chamber on back