They've got two of those excellent small KLH drivers per cabinet - the same ones used as the midrange in the Model Five and Twelve speakers and the Model Twenty-One radio. And believe it or not they are ported - probably the only KLH speakers from that era that are. They were also available in a super thin wall hung version as the Model Fourteen (no "b" suffix) which you can see here
. I'm not 100% sure but I think your version of the Fourteen came with one of the phono systems (like the Eleven-W) and could also be purchased separately.