User Manual

Do not place a taller/larger or heavier speaker system than the DM
™
115 on this pole, or it may be unsafe due to the
potential to tip over.
The DM Sub must be placed on firm and level ground, in order for the pole mounted speaker to be safe from tipping.
When installing or de-installing the speaker on the pole, it is a good practice to have a helper, if possible. It can be hard
to "thread the needle" and mate the pole cup to the Subwoofer pole while holding the speaker system at arm’s length.
When using the DM Sub and pole outdoors, never attach banners or flags to the pole or the pole mounted speaker
system, as strong winds may cause the speaker to blow over. If there is a possibility of strong windy conditions, then
it may be prudent to consider removing the speaker from the pole to prevent the DM Sub and pole mounted speaker
system from being blown over.
CONNECTING AC POWER TO THE DM SUB
The DM Sub comes with a 6-foot IEC connection AC power cord. If you are using an extension cord or power strip
with this powered speaker, make sure it is of good quality and of a sufficient current capacity to maintain safety and
maximize the power output capability of the DM Sub. For maximum undistorted output, do not connect any other
device to the same extension cord that the DM Sub is connected to. Do not exceed the rated current capacity of the
extension cord with the sum total of all units connected to it.
When first plugging in the DM Sub AC cord, make sure the power switch is in the Off position, and then turn it On
only after connecting the power cord. Built-in muting will engage when the proper sequence of steps is taken.
SPECIAL NOTE FOR PERMANENT INSTALLATION
When installing the DM Sub, AC power runs will be used and a certified electrician should be consulted to be sure
that all AC wiring complies with local codes and regulations. It is also advisable to use a cable clip properly affixed to
the cabinet to provide strain relief to the IEC power cord connected to the amplifier module at (2) so the power cord
cannot be pulled out or vibrate loose.
CONNECTING A SIGNAL TO THE DM SUB
There are a variety of ways to input a signal into the DM Sub.
The input (4) provides a balanced line-level input, allowing the use of a 1/4" TRS (ring-tip-sleeve) type phone plug
or a male XLR plug. Of course, an unbalanced 1/4" phone plug can be used as well, but it will not have the benefit of
the balanced connection's rejection of outside interference, such as hum and RFI.
Do not connect cables to the jacks while the unit is ON and the Level knob is turned up! While a standard
single-ended 1/4" phone plug-equipped cable will work well and the balanced input circuitry will provide some
interference rejection, a balanced cable using either the balanced TRS 1/4" phone plug or the XLR plug will provide
superior interference rejection and performance.
Sometimes, with difficult interference problems, it will be helpful to lift the shield ground ( Pin #1 of an XLR) of a
balanced cable at the DM Sub end. This can be done quite easily, by activating the Ground Lift switch (10) built
into the DM Sub. Check any input changes carefully, always turning the Level control down before plugging and
unplugging cables or lifting the ground.
Use of high quality, premium cables is recommended for the DM Sub, as these usually have better shielding and
materials and will provide greater long-term reliability. The best option is a shielded balanced cable no longer than
necessary to reach the DM Sub. It is usually a good idea to leave some slack at the input to the DM Sub and also to
tape the cables down or run them under a cable guard, to avoid anyone tripping over them or pulling the DM Sub
over when it is holding a speaker on top of its pole.
LEVEL CONTROL ADJUSTMENT
The DM Sub is equipped with a Level control (6) on the input to facilitate use in many different applications. With the
Level control adjusted fully clockwise, gain is at maximum and the input sensitivity is 0.24 V RMS for full-rated output.
It is recommended that the DM Sub Level control be set close to 12 o'clock position, or 0 dB preamp gain. At this
setting, the input sensitivity is approximately 2.4 volts RMS for full-rated output. The DM Sub will now more closely
match a typical power amp input.
If the mixing board indicates clipping of its output signals, then all of the DM Sub power capability is not being
utilized cleanly. Clipping the signal before it gets to the DM Sub is not optimal. Reduce the mixer output level and
turn up the Level control on the DM Sub.