If it's a well designed combo, it has a built in high pass filter matched with the speaker's range right before the power amp to avoid this danger. Of course, I wouldn't count on every manufacturer to do this and with separate amp and cabs, there's no way for the amp manufacturer to know what the cabinet used will actually handleYeah. What you said! My point being that my lowest note (low B) is at the frequency of 31hz, if memory serves. That's what my cab cab (safely, I know it's not a hard cut off) produce according to its specs. So I don't want to damage that, regardless if I can hear it.