Calibre 914 is based on its predecessors, Calibres 910 and 911, but with significant improvements. It beats at a modern 28,800 A/h rather than 19,800 A/h as in the previous models. It is upgraded with 18 jewels, one more than before.
But the most significant improvement is the use of a nicer-sounding gong for the alarm function. One benefit of ringing a gong rather than the case back is that, for the first time, a Jaeger-LeCoultre Memovox can have a transparent sapphire case back, allowing the movement to be viewed.