is a DCR?
DCR is short for Double Chamber Reflex. It is a little
known variation of a Bass Reflex. Unlike
a conventional Bass Reflex, where a single port determines
the lowest bass, a DCR has two ports, one for the
lower bass and the other for the upper bass.
manner in which this is accomplished is by way of
2 internal chambers. In the larger chamber where the
woofer is located, the main port fires outwards for
the lower bass. Simultaneously, an internal port fires
into a smaller chamber below. A third port in this
secondary chamber then fires outwards for the upper
is this added complexity that separates the bass performance
of a DCR from a Bass Reflex. With the assist of a
secondary chamber, a DCR is much more articulate in
the upper bass. It is equivalent to boosting the upper
bass with an equalizer. Instead of doing it electronically,
a DCR does it acoustically.
the Near Field Response on the right, the outputs
of the 2 ports are clearly defined. The green plot
centered at 45Hz, is the output of the lower bass.
The violet plot, with a slight peak at 80Hz, is of
the upper bass. Note how well it bridges the gap between
the lower bass and the roll off of the woofer (red