The Bass Ranger EQ Module is a graphic equalizer for the bass range
with passive coil filters in eight bands. It employs bell filters, each with
individually optimized bandwidths, boost and cut values.
The concept of the Ranger EQs for the RackPack modular system is
characterized by two decisive features that separate them from tradi-
tional designs. First there is the basic idea of specialized modules for
typical instrument or vocal ranges. This follows a consistently musi-
cal approach, but also the design of each filter is based upon musical
demands alone—center frequency selection is not governed by techni-
cal ISO rules, but relies on our own experiences and the preferences of
In contrast to statical graphic EQs with always the same center fre-
quencies in repeating octave distances, the Ranger EQ modules are
much better suited to work with specific instruments and their pecu-
liarities—and only different frequency ranges do allow to effectively
separate instruments in a mix.
The second characterizing feature follows the idea of a modular design
and affects both the filter technology and the user interface. Why did
we chose a graphic EQ design? For a fully parametric EQ with all neces-
sary controls there would be space for one band on the module front.
Our graphic EQ offers eight bands—a bandwidth control is less impor-
tant, and different EQ modules can be combined to configure a large
and, if needed, complex EQ system.
But a traditional graphic EQ with an active filter design did not seem to
match our idea of a holistically musical approach. We decided for a rare
technical solution: the combination of passive filters with a graphical
user interface. Based upon individually specified, custom-made coils,
these filter designs convince with outstanding musical qualities.
Finally, the general advantage of modular systems becomes clearly
obvious when planning individual systems: A vocal recording channel
with RackPack modules can be configured in very specific ways, while
a complex EQ system may have a completely different focus.