User manual VELODYNE DD-18PLUS QUICK GUIDE

[. . . ] Please observe the following instructions to insure safe and proper system operation. Note: Do not leave unit in direct sunlight or use in high humidity environments!!!To prevent fire or shock hazard, do not expose this equipment to rain or moisture. To avoid electrical shock, do not open speaker enclosure or amp chassis cover. [. . . ] True subwoofers operate at extremely low frequencies which are primarily omni-directional. Additionally, this lack of signal may also cause the subwoofer to produce less output than it is capable of. . www. velodyne. com Impact Series User's Manual 2 To alleviate this condition, we recommend the following steps: 1) If using line level jacks, BOTH THE LEFT AND RIGHT INPUT CAN BE USED ­ never use just the left or just the right input. If the subwoofer's signal comes from the LFE channel of your receiver, use a "Y" splitter to connect to both the left and right inputs. If using line * level connections from a preamp or signal processor, use both Left and Right inputs from your preprocessor or preamp and connect them to the Left and Right inputs on your subwoofer. (See figure 2a on page 7. ) * This dual male-to-female "Y" splitter can be found at your local electronics store. 2) If using a receiver with LFE out, be sure the LFE channel is sending adequate signal to the subwoofer. We recommend setting the subwoofer's level to the 9 o'clock position (the 1/4 volume setting) and then adjust the LFE channel on your receiver or processor to achieve the desired bass output. See your receiver or processor's owner's manual for more information. (See figure 2b on page 8. ) The SPEAKER LEVEL jacks connect directly to the speaker outputs of any amplifier, integrated amplifier, or receiver. Your amplifier section will notice no additional loading effects when you use these inputs due to their very high impedance. If using the SPEAKER LEVEL inputs, you DO want to connect both channels, since different bass information might be present in each channel going to your main speakers. Important!!! Do not use both LINE LEVEL and SPEAKER LEVEL connections simultaneously!More detail of these connections can be found below: (1) (2) LINE INPUT jacks - Connect these jacks to the LINE OUT jacks of the amplifier. SPEAKER LEVEL OUTPUT terminals - The speaker-level signal to the front speakers is output from these terminals. SPEAKER LEVEL INPUT terminals - Connect these input terminals to the speaker output terminals of your amplifier or receiver. PHASE switch - Select the switch position at which you hear a louder mid-bass sound. Impact Series User's Manual (3) . (4) www. velodyne. com 5 (5) VOLUME LEVEL knob - Use this knob to adjust the output level of the subwoofer. LOW-PASS CROSSOVER - Use this knob to select the high-frequency range at which you wish to cut-off the signal to the subwoofer. POWER INDICATOR - Red: Unit is in standby mode. (automatically turns to STANDBY mode if no signal for eight minutes) (6) (7) C ro s s ov e rs Receiver/Processor Subwoofer Outputs The Velodyne subwoofer is designed to operate using the full range audio signal for input when using the built-in crossover. Many home theater processors/receivers (Dolby DigitalTM, DTSTM, THXTM) have a "subwoofer out" jack (sometimes labeled "LFE") that is internally filtered, settable at the receiver/processor, and designed to be used with a powered subwoofer. In some installations, it may be beneficial to use BOTH the Velodyne crossover and the receiver/processor crossover, resulting in a steeper ultimate crossover slope. In some rare cases, combining both an external crossover and the one internal to the subwoofer may result in low output and increased noise. In these installations you may need to bypass the crossover in either the processor or your Impact subwoofer, or simply setting one crossover to a higher frequency (such as 120 Hz) will restore maximum performance. [. . . ] Normal operation should return upon cooling, but you may be required to turn the power off and then on again to reset the unit. The following conditions require service by a qualified technician: 1. The unit does not appear to operate normally or exhibits a marked change in performance 3. Some part of the chassis or circuitry is physically damaged 1. [. . . ]