A theoretical ideal for audio components, especially speakers, representing a frequency response that does not deviate from a flat line over the audible frequency spectrum when fed a flat-line test signal. peaker designers attempt to create a flat response in their products using many different methods. Anytime a speaker deviates from the supplied signal, it is distorting the input signal and recreating a sound that is not exactly true to the original. flat response is indeed ideal, but is impossible in real world listening due to not only the speaker itself but also its interactions with the room and various surfaces within the room. A speaker can often be moved and adjusted to achieve a flatter frequency response within a given room, and an equalizer can be used to further flatten the response if necessary (although equalization is typically a last-resort effort to correct a fairly severe response problem which cannot be corrected with other means). enerally, a speaker (or any other audio component for that matter, but speakers in particular) is said to have a flat frequency response within a certain range. For instance, a speaker may be said to have a flat response from 50 Hz to 18,000 Hz within plus or minus 2 dB (decibels). This simply states that the speaker is within 2 decibels of a flat response within the frequency range of 50 Hz to 18,000 Hz (it can be 2 decibels too loud or too soft at any frequency in the given range). All speakers will fluctuate above and below the ideal flat response. Speakers staying within two or three decibels of a flat response are thought of as being very linear and very nearly flat in their response. Furthermore, most speakers will drop in response in the lower frequency extremes and upper frequency extremes, however, these areas are outside the most critical midrange frequencies to which human hearing is most attuned.