What is :DIN i.e.Low-Frequency Extension 43 Hz

I have seen some speakers rated i.e:

Low-Frequency Extension* 43 Hz (DIN)

What does DIN stand for?


Its a European standard.I can't remember +-how many db.Somebody else may have better info.LINK>>>[http://en.wikipedia.org/wiki/Deutsches_Institut_f%C3%BCr_Normung]
by Hifitime
Deutsches Institut für Normung (German Institute for Standardization)

Audio is covered by DIN 45500.