I was looking at a manufacturers web site and noticed that one version of their spec had frequency response of 50Hz-20kHz. Their PDF data sheet for the same produce said the frequency response was 70Hz-18kHz. That felt like a real difference, so I emailed them. They got back to me and said the wider measurement was done with a +/- 6db tolerance while the tighter measurement was done with a +/- 3db tolerance. He explained that response tapers off at the ends and this was normal. Yet most people, including this manufacturer, don't seem to typically disclose the tolerance for the test. Is that because they all do it at +/- X db and this case is a fluke or do they all pick a tolerance that suits their specs well? Thanks...Millard PS: Maybe I've been doing this wrong all along -- if the cab is "rated" to 46Hz, I've been EQing away any signal below that level, not wanting to pump a bunch of low-end into a cab that, by admission, isn't interested.