Between 100-300 I think the advantage is placement near a wall, particularly for nearfield type monitors.
A cardioid is surely a foolproof solution to this placement problem, yet a rather expensive one. Particularly in a nearfield environment without room modes dominating, the frequency band 100-300Hz is rather easy to deal with using a DSP correction.
Aside from dipoles I'm not aware of any compact solutions for directivity control from 100-200hz.
A line source would do this job, but could hardly be called ´compact´, if effective all the way down to 100Hz. The question is why you need such directivity control? This is the frequency band in which directivity errors are least likely to become audible, hence easily equalizable, if there is no sudden step in directivity towards a neighboring band.
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