I have to agree with Mdhoover and some others who are arguing against the "greater frequency reposnse is necessarily better" viewpoint.
Quality reproduction in the 80 to to 12Khz range is more desirable than a speaker that is "flat" from 20 to 20 Khz but suffers from significantly more harmonic and IMD distortion.
Furthermore, an SPL meter and a test CD will give practically everyone who owns a speaker with a flat reponse from 20 to 20 KHZ a surprise....as most rooms have between 10 and 20 DB response fluctuations (peak to trough) below 80 HZ. This is unavoidable and is caused by standing waves....room treatments can help some but fundamentally some fairly big bumps will remain unless they are equalized out, and then, even equalized, the reverberation problem remains and any EQ'd flat response is limited to a small sweet spot.
A further problem of a speaker with flat extended LF response (no roll off) is that LF frequencies radiate in ALL directions...therefore they reflect off the rear wall and will boost by +6db at some frequencies and will cancel out a quarter wavelength from the wall (producing more frequency response bumps in addition to room modes)
Which all goes to show that flat frequency response down to 20 Hz may not necessarly be a good thing in a speaker.
Quality reproduction in the 80 to to 12Khz range is more desirable than a speaker that is "flat" from 20 to 20 Khz but suffers from significantly more harmonic and IMD distortion.
Furthermore, an SPL meter and a test CD will give practically everyone who owns a speaker with a flat reponse from 20 to 20 KHZ a surprise....as most rooms have between 10 and 20 DB response fluctuations (peak to trough) below 80 HZ. This is unavoidable and is caused by standing waves....room treatments can help some but fundamentally some fairly big bumps will remain unless they are equalized out, and then, even equalized, the reverberation problem remains and any EQ'd flat response is limited to a small sweet spot.
A further problem of a speaker with flat extended LF response (no roll off) is that LF frequencies radiate in ALL directions...therefore they reflect off the rear wall and will boost by +6db at some frequencies and will cancel out a quarter wavelength from the wall (producing more frequency response bumps in addition to room modes)
Which all goes to show that flat frequency response down to 20 Hz may not necessarly be a good thing in a speaker.