Manual
www.velodyne.com
Digital Drive Series User’s Manual - 41
ABOUT ROOM EQUALIZATION
This section gives some background on room equalization. As a sub plays in a room, the reections of the
sound waves o the walls create “standing waves,” that is, places in the room where certain frequencies are
louder and others are diminished. In addition to standing waves, every room will also have locations where
cancellations of the sound waves are like black holes that no amount of attenuation can ll. Thus as a general
rule it is better to “cut down” a peak of response rather than to “boost up” a valley (i.e. possible black hole) of
response.
In general, you are looking for a frequency response that is +/– 3 dB at all frequencies (it is highly doubtful
that your ear can tell a response that is any better than this). The response will always roll o at the low end
(according to the settings of the subsonic lter), and there should be no dip or peak at the crossover frequency
with the satellites. While the goal is perfectly at response, this may not be possible in the higher frequencies
of the subwoofer’s response due to peaks or valleys introduced by the satellites.
PROTECTION CIRCUITRY
Your new subwoofer is equipped with special protection circuitry to provide maximum performance with greatest
reliability.
The unit is protected against:
1. Overdriving the speaker or amplier.
2. Overheating the amplier.
3. Excessive drop in power line voltage.
The rst type of protection circuitry that prevents overdriving of the speaker or amplier operates constantly
without being audible under most situations. In some extreme situations (sustained high output levels such as
pro sound usage), the unit may shut down momentarily. This indicates operation of the thermal or under voltage
protection circuitry. If this should happen, you should reduce the volume setting or shut the unit o until normal
operating conditions return. You may also want to plug the unit into a dierent wall outlet, as dropping power
line voltage will be most noticeable under strenuous conditions.
CARE OF YOUR DIGITAL DRIVE SUBWOOFER
Do not use any harsh detergents or chemicals to clean the cabinet. Abrasives, detergents, or cleaning solutions
may damage the nish on the cabinet. We recommend using a damp cloth to clean the cabinet. During normal
conditions, your new subwoofer may be left on continuously without any problems. The unit is equipped with
a signal-sensing turn on/o that will automatically turn on the unit when a signal is present at the inputs and
turn o the unit after several minutes when there is no longer any signal at the inputs. If you plan to leave the
subwoofer unused for an extended period of time, we recommend that you unplug the unit.