User Manual
Radial Engineering Ltd. J48 Stereo™ User Guide
7
USING THE HIGH-PASS FILTER
USING THE POLARITY REVERSE SWITCH
A very handy feature that is built into the J48 Stereo is the high-pass lter. When activated,
it gently rolls off low frequencies below 80Hz and helps eliminate resonance and feed-
back. This handy feature is particularly effective at cleaning up the low registers, making
it easier to mix.
The other benet with eliminating bass is that you actually increase the available dynam-
ics. Low frequencies and their huge waves require more power than their high frequency
counterparts. Reducing low frequency content in the music program results in more avail-
able headroom and less distortion.
The RIGHT channel on the J48 Stereo is equipped with a polarity reverse switch that
toggles pin-2 and pin-3 on the XLR. This handy feature can be used in several ways:
1. Stereo Imaging
In some instances, particularly when recording – changing the relative phase between
the left and right channels can produce very pleasing results. Similarly, when using two
sources such as combining a magnetic pickup with a piezo on an acoustic guitar, chang-
ing the relative phase between them can sometimes produce a more natural sound.
2. Eliminating Feedback
Resonant feedback on a live stage is often produced when sound sources such as the
PA and stage amp combine to create a hot-spot at certain frequencies. This can cause
an acoustic instrument to vibrate, resulting in low frequency feedback. This can often be
minimized by reversing the polarity at the XLR, electronically moving the problem out of
the way, without having to resort to excessive (tone altering) equalization.
3. Adapting to non-AES standards
When interfacing with older vintage audio equipment, the polarity may be reversed where-
by pin-3 may be hot. Depressing the polarity switch lets you match the phase if needed.
As this switch is recessed, use a
small screwdriver to activate.