Some companies stick to the standard +/- 3dB deviation for frequency response, while others will list bass extensions as numbers -6dB or even -10dB. Is this just a way to make their specifications look better? How many dB, can you still see the bass feedback that can be used?

Subquestion - for a classical rock and folk listener, is there even a point in getting into the 20Hz range? The lowest bass note of a bass guitar is 31Hz and the lowest key of the piano is 27.5Hz. Looking at the instrument frequency chart, you get almost everything at 60Hz or higher. Amazingly and enlightened when I looked at one of those charts and realized how many instruments actually dropped below 60Hz