We’ve seen the response curves with the bass settings maxed out, and since all of these speaker systems have a bass (or subwoofer) level control, let’s examine the ranges that the user can play with:
Some of these systems have more bass level control than others. There may be situations where strong low-frequency sounds might be disruptive, so the more control the better.
Now let’s consider the Rockus 3D|2.1 in music and 3D modes:
The yellow and orange lines represent the minimum and maximum bass settings in music mode, and the green and purple lines represent the maximum and minimum bass settings in 3D mode. There’s not a great deal of variance here.
Finally, since the Rockus 3D|2.1 is the only system with both analog and optical inputs, let’s see if there’s much difference between them. The following graph doesn’t show a frequency response, but it shows the difference in responses between the optical and analog inputs. A perfectly flat line would mean there’s no difference at all:
There’s a slight difference here in the sub-bass range below our hearing capability, but nothing too disconcerting, and probably not anything someone could notice. The fact is that the optical input is most useful when the PC’s sound hardware is sub-par, but most codecs that support optical output also offer decent high-definition audio in the first place.