hi, in that situation you would probably be ok, but keyboard generated instruments can produce some low notes ... a double bass's lowest note is in the same frequency range for example...though in the case of strings, it is not very often you would be down that low, and they lack the dynamic "punch" of particularly the kick drum, which has a very sharp transient peak and it is very repetitive ...BUT the first release units did have a habit of burning out their coils (commonly referred to as blowing up),or the other thing was that the cone extended so far on the particular woofer that jbl used, that the coil wires broke i am not sure of the numbers as it was hearsay amongst audio techs i dealt with, but significant enough for it to be a topic of conversation, much the same as the power supplies causing damage on behringer gear being used in australia...
bthmedicine, this is only a "heads up" as a)it happened to me and b) audio techs confirmed it was a problem with some, not all!!
dennis
PS i think JBL changed the woofer in later models..mine were the first release, which was about 1998-99 somewhere around then...