 The NS @-@ 10 does not have a perfectly flat frequency response . The sound of the NS @-@ 10 is slightly heavy in the midrange , and like other sealed @-@ box speakers of similar size its bass extension is limited . It has a + 5 <unk> boost in the midrange at around 2 kHz , and the bottom end starts rolling off at 200 Hz . The midrange response is so open that it exposes the frequencies that are the most problematic and worst @-@ sounding to the human ear . 
