SV Subwoofers
Page 10
from the sub. But don’t despair if you don’t hear much difference, especially if running a
single subwoofer. Bass “cancellation” will vary by room shape, volume, and the bass fre-
quency. No one setting is likely to be perfect. One technique to optimize phase is to find a
nice “bassy” loop (such as the menu of the “Godzilla” movie DVD or favorite music disk)
and measure the loop’s SPL response at various bass peaks. As the loop runs, have an
assistant adjust phase in small steps while you measure. When you see the most response
on a given bass passage, typically that’s the setting with the least cancellation (for the
frequencies of the demo loop). Listen for depth, smoothness, and integration with the
mains too.
Line In/Out. Use either of the sub’s “Line In” jacks to connect the subwoofer to the out-
put jack of your receiver/processor. Feeding just one input is enough. If you are using a
conventional amp and/or a stereo setup you can use the “Line Out” jacks to send sound
(filtered of deep bass information) back to your system amp. A simple RCA to RCA cable
is all you need for either type configuration.
Auto On. Your Powered Box allows itself to be in an “Auto-On” mode… or “On” all the
time. With the former setting (the switch in the “Auto” position) your subwoofer will
“sense” that a DVD or CD etc. has begun and switch its audio circuits on immediately (the
“hard” power switch mentioned below must be on, naturally). A few minutes after a your
listening, the Auto-On light will turn Red, switching parts of the sub back off. When run-
ning (and sensing a signal) the Auto-On LED will be green. Sometimes, with very low
listening levels, your subwoofer might not get enough of a bass signal from your surround
sound processor to “trip” the Auto-On circuit. Should you ever find this to be the case you
may leave this switch to “On”, or turn up the receiver’s subwoofer level control some (be
sure to recalibrate channels levels with your meter afterwards).
Crossover enable switch. If you allow your DD/DTS surround-sound receiver or proces-
sor to manage bass frequencies (again, highly recommended), this switch should be set to
“Disabled”, eliminating the effects of the “Crossover Frequency” knob and allowing your
sub to reproduce just what it’s fed from the receiver. If you use the sub in a two channel
(stereo only) configuration, then “Enable” the crossover and adjust the knob to best blend
the sub into the output of your speakers.
High level inputs/outputs. Not commonly used today, but binding posts are there in case
you don’t have low-level inputs/outputs on your receiver/processor. Typically utilized
only if you are not using a DD/DTS compatible system.
Power. This heavy-duty two-position switch next to the power cord will completely cut
the power to your sub amp. Flip this switch to off before you ever move the sub or change
inputs or outputs.
A/C connection. Plug your sub into a dedicated A/C outlet. “Convenience” outlets of
typical receivers often don’t provide the needed current. Do not use these.
Fuse. User replaceable, contact your dealer if you have trouble finding one. The fuse can
be accessed by a small door immediately next to the power cord fitting
(where you should also find a spare fuse for your use).