if you refer to techno vinyl cuts...yes

but for commercial recordings you will come across 60hz roll off quite a bit.

i was comparing rock to techno.

with techno its all good. give it heaps in all frequencies right down to 20Hz.

its just what i have noticed from being in the rock world initially then progressing to techno - i noticed a big difference. maybe i am old??
but i've worked with a lot of rock soundies and rock PA. Sub doesn't come into the equation. Even bass guitar amps roll off early and rock kick drums don't work at that region either.

the commercial narrow freq band comes from having to comply with some ancient concept that most recievers are only good for this range (which they still typically are).

the article does mention the freq range as you mentioned in quote. it is a good article. but many techno producers i come across still think that the frequency response from a set of Behringer "Truth" monitors (or similar) is enough - they technically offer this response but not in the same way as a sub network system. (some even only reference off head-phones!!??).

just commenting on my experience. and adding some more :)