Volume Control Adjustment

Use of high-quality premium cables is recommended for the QW 118P. These cables typically have better shielding and materials and will provide greater long-term reliability. It is also a good idea to leave some slack at each end of the cable connection and tape the cables down or run them under a cable guard to avoid accidents.

The QW 118P is equipped with a Master System Level volume control (6). When the Master System Level volume control adjusted fully clockwise, gain is at maximum and the input sensitivity is 0.375 V RMS for full- rated output. When this control is set halfway up, gain is unity and 1.5 VRMS will drive the system to full power output. When driving the QW 118P from a mixer, it may be advantageous to reduce the input sensitivity by turning the volume control to the halfway point. At this setting, the QW 118P will more closely match a typical power amp input.

The amplifiers in the QW 118P are equipped with DDT™. This unit also includes an LED (11) that illuminates when DDT is activated. This LED is located next to the Master System level. The DDT circuit will automatically reduce the channel gain to a level just slightly into clipping, guarding the speakers against the damaging high power continuous square waves that may be produced. Situations that may activate the DDT circuit include uncontrolled feedback, oscillations, improper equipment settings or malfunction upstream from the amplifier.

Always turn on any peripheral units before turning on the QW 118P. Also, make sure the Master System level is completely down (fully counterclockwise) before turning the unit ON.

Adjusting the kosmos® Processing Level

The amount of kosmos processing is controlled by the Master System Level knob. In order to achieve more sub- harmonic processing, turn the Master System Level (6) up, and the Level/Quake knob (7a) down.

When using the QW 118P with a passive, full-range speaker system, the relationship between the Master System Level and the Quake/Sub Level will determine the balance between the overall subwoofer output and the high frequencies that are sent to the left and right speaker outputs (9). The amount of kosmos processing that occurs will not be able to be controlled independently. It can, however, be bypassed using the Bypass switch (7c).

When using the QW 118P with a powered, full-range speaker system from the line-level high pass outputs (8), the powered full-range speaker system will usually have their own volume control. This will allow the high frequency level to be set independently. However, the kosmos Xpanse control (7b) for adjusting the stereo spread can only be adjusted at the QW 118P subwoofer.

High Pass Outputs

These are low impedance, filtered outputs provided to send the high frequencies to a powered speaker or a conventional power amp and speaker system. The output level is set by the Master System level control on the QW 118P.

The nominal polarity of these outputs is pin 2 positive and can be run directly into most full-range, powered speaker systems.

If you experience hum or related ground loop problems, it might help to lift the shield ground on the balanced XLR cable at the QW 118P end. This can be accomplished via the convenient ground lift switch (10b) located underneath the high pass output jack group. Check any input changes carefully. Always turning the Volume control down before plugging and unplugging cables or switching ground lift switches.

Left and Right Outputs

These outputs will supply a full-range, 8 Ohm minimum speaker system with a high-passed amplifier signal when using the QW 118P as a three-piece system. The Xpanse control (7b) will expand the stereo sound stage and add high frequency processing to these outputs.