Operating instructions

19THE OUTLAW’S GUIDE TO THE SMS-1
anywhere between 15Hz and 199Hz, but the recommended maximum
setting in the user’s manual is 35Hz. The slope of the subsonic lter can
be set to 6, 12, 18, 24, 30, 36, 42, or 48 dB/octave, just like the low pass
crossover’s slope. As with the low pass crossover, a higher slope will cause
a more rapid drop-o at the crossover frequency. Unlike the low pass
crossover, the subsonic lter cannot be disabled, so if you have a sub that
can go really deep you should probably set the subsonic lter to 15Hz and
keep the slope fairly shallow.
Phase and Polarity are some interesting cousins of one another. You may
have previously seen a phase control on your subwoofer. Typically this is a
toggle switch oering the choices of 0° and 180°, although in some cases
it is a knob oering adjustment between 0° and 180°. You have also seen
a form of phase control on every speaker you have ever connected: the
positive and negative speaker terminals. If you connect those terminals
correctly (positive at amp to positive at speaker), then the speaker is con-
nected in phase (the 0° setting). If you connect the terminals backward,
you get 180° out of phase. Why would you want or need the ability to hook
your subwoofer up “backward” (the 180° phase setting)? That gets into
part of the big picture issue that led you to purchase an SMS-1 in the rst
place: speaker placement in your room and interaction with your room.
A subwoofer is sharing its signal with other speakers (most often the left
and right channels, but to a degree the center and surrounds as well), but
it is usually not located symmetrically with those speakers and is playing
back low frequencies that have very long wavelengths. Adjusting the
phase of the subwoofer can help it match up with those speakers in spite
of its separate placement. In general, subwoofer phase switches are set
by playing a test tone and using the switch position that gives the loudest
output. While limiting you to two choices makes that process simpler than
having a bunch of choices between 0° and 180°, it may not give you the
best results. After all, your subwoofer may work best in your room with a
phase setting of 110°. That’s where these Phase and Polarity settings come
into the picture. Polarity is actually going to do exactly the same thing
as the 0°/180° switch on most subwoofers. It will switch the polarity from
positive to negative, simulating a complete 180° change in phase. The
Phase setting allows you to tweak the subwoofer phase in 15° increments
between 0° and 180°. Between those two, you can set your phase to any of
two dozen positions. These are settings that can take a lot of tweaking, and
can even be used to try to smooth out the curve on the System Response
screen before you start working through all the equalizer channels. If you
want to nd the best setting for your Phase and Polarity, you may want to
toggle between the System Setting and System Response screens as you
make adjustments to the Phase. When making changes to these settings,
you can use the “TEST” button on the remote to quickly jump to the System
Response screen and see how those changes aect the curve. The goal
is to achieve the attest response in the area centered on your crossover
point, where the subwoofer and mains blend together. The ideal phase
setting will give the smoothest curve in this area. Pay particular attention to
dips in the response curve in this area, as it may be easier to adjust such dips
with Phase and Polarity than with equalization.
The next one looks easy enough, right? It’s Volume – one we’ve all seen
before. In this case, the Setup setting behaves a little dierently than
elsewhere in the System Settings screen. Changing the Setup volume will