A quote from Alan's article.
A simple claim of frequency response that cites two frequency extremes unqualified by a dB specification (e.g., frequency response: 34 Hz - 22 kHz) is meaningless and useless. It may mean that although the speaker responds at 34 Hz--the cone moves a bit, perhaps--nothing will be audible because the speaker's response at 34 Hz is at -30 dB and inaudible! On the other hand,
if Axiom states that the M80’s frequency response is 34 Hz - 22 kHz +/-3 dB, this indicates that every tone that emerges from the M80 will be within 3 dB of any other over that entire frequency range. Alans article
