SubContractor Series - OneCall

(16) Auto ON/OFF SwitchUse this switch to select between auto-on active and auto-on inactive (constant on) operation.For maximum amplifier life, we recommend the Auto ON/OFF “Active” setting.(17) Speaker Level Output Terminals (See Figure 5)These connections send a crossed-over speaker-level signal to the front speakers. Whenconnected in this fashion, your satellite speakers will be crossed over at 80 Hz. Thisremoves the lower bass frequencies from your satellites, enabling them to do a better jobreproducing high frequencies and giving your receiver’s amp more headroom (up to 50%more power).You may also connect your satellites directly to your receiver or amplifier along with thesubwoofer if you wish to bypass this crossover.Figure 5: Speaker-Level Connection.www.velodyne.comSubContractor User’s Manual8

(18) Speaker Level Input Terminals (See Figure 5)Connect these input terminals to the speaker output terminals of your amplifier or receiver.If you use this method of connection, when you go to the receiver speaker set up menu, makesure you select the “large” speaker option.(19) Subwoofer Connection TerminalsConnect these output terminals to the subwoofer(s) being controlled by the SC-1250. Onlyconnect ONE subwoofer per red/black pair of subwoofer output terminals - DO NOT connectthe subwoofers in a “daisy chain” configuration.Note: SC series subwoofers are designed so that TWO subwoofers can be driven from asingle SC-1250 amplifier. If you are using the SC-1250 to power a non-SC subwoofer, makesure you check the resistance of the subwoofer’s voice coil. A SINGLE 4 ohm subwoofer canbe driven with the SC-1250, but not TWO 4 ohm woofers. If you attempt to run more than asingle 4 ohm subwoofer, internal protection circuitry will activate within the SC-1250.Caution!!!To avoid damage to your SC-1250, be sure to maintain correct polarity when making allconnections. Red (positive) to red, and black (negative) to black. Be sure that all connectionsare tight, and that there are no loose strands or frayed wires.(20) Power Cord AdaptorConnect the detachable 117V 60Hz 15A AC power plug to this male interface connection.The detachable cord allows for easy replacement should the original be damaged.(21) FuseIf the unit is not functioning, check the fuse. If the fuse is blown, replace with an identicallyrated fuse. If the fuse blows again, refer the unit for service.(22) Master Power SwitchPress the POWER switch to the ON position to activate the amplifier. If the unit is to be leftunused for an extended period of time, move this switch to the OFF position to prolong thelife of the amplifier.REAR PANEL CONNECTIONS – DETAILED EXPLANATIONThe SC-1250 is equipped with both speaker-level and line-level inputs. Use the RCA/Phono type“INPUT” jacks when connecting from a pre-amp, signal processor, or line-level crossover. The“SPEAKER LEVEL INPUT” jacks connect directly to the speaker outputs of an integrated amplifieror receiver. Your amplifier section will notice no additional loading effects when you use theseinputs because of their high impedance.Note: Do not use both the RCA/Phono “INPUT” connections and “SPEAKER LEVEL INPUT”connections simultaneously.About Low-Pass CrossoversAll of the SC-1250 inputs sum the left and right channels together and the resulting signal ispassed through an adjustable low-pass crossover before being amplified. The crossover controlallows you to adjust the upper limit of the subwoofer’s frequency response from 30 to 160 Hz.The subwoofer’s response will begin rolling off above the frequency you set this control to. Theslope is 24 dB/octave.www.velodyne.comSubContractor User’s Manual9

You should set the crossover frequency to obtain a smooth and seamless transition from thesubwoofer(s) to the main speakers in your system. If your main speakers are smaller units withlimited low frequency output, you may wish to choose a higher frequency (such as 100-120 Hz)than you would with larger speakers which have greater low frequency output. With largerspeakers, you might start with this control set lower, such as 80 Hz. The SC-1250 crossoverhas a default of 80 Hz.Most receivers and processors provide an option to characterize main speakers as “large” or“small.” This affects the crossover point. We recommend in most cases setting the mainspeakers to “small,” despite their size and frequency response characteristics. This is becausethe powerful 1250 watt SC-1250 combined with the SC subwoofer(s) you have acquired aremore than likely more suited to low bass reproduction than your amp and main speakercombination. With the burden of low frequency reproduction relieved, your amplifier and mainspeaker combination will enjoy better performance and about 50% more available headroom,enabling them to more accurately reproduce the rest of the frequency spectrum.Disabling the Low-Pass Crossover (Subwoofer Direct)If your receiver/processor provides a crossover to the subwoofer(s), you may want to bypassthe SC-1250’s low-pass crossover. To do this, depress BOTH the Crossover UP and CrossoverDOWN buttons simultaneously. The numeric LED will showindicating that the low-passcrossover has been defeated. To reactivate the low-pass crossover, simply push the crossoverUP or crossover DOWN buttons.--A W o r d A b o u t Yo u r R e c e i v e r ’ s C r o s s o v e rand the SC-1250 CrossoverYour Velodyne SC-1250 amplifier is designed to operate using the full range audio signal forinput when using the built-in crossover. Many home theater processors/receivers (DolbyDigital , DTS , THX ) have a “subwoofer out” jack that performs this same function and aredesigned to be used with a powered subwoofer.In these installations, you may want to bypass the crossover in either the processor or theVelodyne SC-1250 as described above. However, in some cases you may want to use BOTHcrossovers. If you choose to do this you should stagger the frequencies, (i.e., 120 Hzsubwoofer, 80 Hz processor) for best results.Note: If not using an external crossover, you should use the built-in crossover for optimalperformance. When using a single RCA sub out from the processor, it does not matter whichline level input (L/R) is used.A Word About Interconnect CablesWhen installing your Velodyne SC-1250 using the line-level connections, you should always usehigh quality shielded interconnect cables. It is recommended that you keep the length of cableas short as possible to avoid any potential external interference problems.When connecting the SC-1250 to your subwoofer(s), use a quality speaker cable that is at least14-gauge. Be very careful to avoid any loose or frayed strands that could result in a short,causing a dangerous condition and possible damage to your unit. Cables of extremely large sizeare typically not required. Extremely large gauge wire may not properly fit in the binding posts,resulting in a poor connection and possible short circuits.www.velodyne.comSubContractor User’s Manual10

A Wor d About Subwoofer PlacementSubwoofers operate at extremely low frequencies, which are primarily omni-directional. Keep inmind that frequency response and output level can be drastically influenced by placement,depending on the acoustic properties of the listening room. Typically, the optimum location fora subwoofer is in a front corner of your listening room. This location will usually offer thegreatest output levels and optimum low frequency extension. The worst location for asubwoofer is typically far away from any walls, close to the center of your room and near anopening or doorway. Avoid these locations when possible. When using a pair of SC subwoofersin stereo, it is preferable to place each subwoofer by the satellite of the same channel. Typically,a minimum distance of one to two feet from your TV to the subwoofer will be adequate to avoidany magnetic interference.Remember that the built-in 7 band EQ will help to get the most performance out of yoursubwoofer no matter where it is placed.Caution!This amplifier has electronics built into the cabinet. Do not place the amplifier next to sourcesof heat such as furnace registers, radiators, etc. Likewise, do not place the amplifier nearsources of excessive moisture, such as evaporative coolers, humidifiers, etc. The power cordshould be routed in such a way that it will not be walked on, pinched or compressed in any waythat could result in damaging the insulation or wire.Selecting the Subwoofer(s) to be ControlledYour SC-1250 can control a variety of Velodyne SubContractor Series subwoofers as well as generic passivesubwoofers. Special internal software settings are designed to maximize performance and reliability dependingon the model of subwoofer being controlled, so it is important to match the SC-1250 amplifier with thesubwoofer(s) it is controlling. The SC-1250 comes with a default setting for the SC-10 subwoofer. When theunit is first powered up, the model being controlled is displayed for 2 seconds on the numeric LED before thedisplay reverts to the volume setting. The subwoofer to be controlled is shown as follows:ModelLED DisplayLED DisplayModel8S C - I n - Wa l l ( S C - I W )IWSC-10I0SC-In-Floor (SC-IF)IFSC-12I2SC-In-Ceiling (SC-IC)ICSC-15I5G e n e r i c S u b w o o f e r **SC-8GS** - The generic subwoofer setting is for passive subwoofers not on the above list. CAUTION: there is no anticlipping or anti-distortion protection on this setting.To change the subwoofer to be controlled, first power down the amplifier using the power switch on the backpanel (DO NOT use the power button on the front panel). Then, turn the switch on while depressing any ofthe buttons on the front panel (crossover up or down, or volume up or down). The unit will show the modelit is currently controlling. To change the model, simply push the crossover up or crossover down buttons andthe model changes on the LED display. Once the desired model is seen on the LED display, simply release thebutton. You don’t need to do anything else - the model to be controlled is automatically stored in the SC-1250’s.www.velodyne.comSubContractor User’s Manual11

memory. To exit model selection mode, use the power switch on the back panel to power down and power upthe unit. You should see the model you selected for 2 seconds on the LED display before the display revertsto the volume.Using the SC-1250 to Drive Two SubwoofersOnce the model selection process is completed, no other adjustments are needed to enable the SC-1250 todrive one or two subwoofers.UsageThis section addresses day-to-day usgae of your SC-1250 amplifier.Remote ControlThe features of the SC-1250 remote control are listed below. POWER — This button forces your SC-1250 unit into standbymode. The power LED turns amber, the numeric LED shutsoff, and the amplifier puts out no power. The unit will remainin this mode until the POWER button is pressed again. To fullydeactivate (i.e. power down) the unit, press the power switchon the front panel.Note: The master power switch on rear panel must be on inorder for the front power button to function. MUTE — This button mutes the subwoofer. The LED on theamplifier will show 00 if the unit is muted. To unmute thesubwoofer, press the MUTE button again and the originalvolume setting shows on the LED.Figure 6: SC-1250 Remote. EQ — This button automatically EQs the subwoofer using a 7 band internal graphic equalizer.To use this feature, first plug the supplied microphone into the Mic-In jack on the back panelof the subwoofer and place the mic in your preferred listening position. Then, by pressing EQon the remote, the subwoofer emits 12 “sweep tones” that cover the frequencies between20 and 150 Hz. The LED displays “AU” during the Auto-EQ process. After the sweeps arecomplete, the unit saves its EQ settings and returns to normal operation. To preventaccidental invocation of the EQ feature, you must hold down the EQ button for 2-3 secondsbefore the EQ sweeps begin.Note: Each time the EQ feature is utilized, the EQ settings for the SC-1250 are reset. If themicrophone is not plugged in, the SC-1250 will emit one or two sweep tones then cease theEQ operation. In this case, the previous EQ settings will be preserved. PHASE — These buttons allow you to optimize the subwoofer performance for the locationand your listening position. Select the switch position at which you hear the most bass. TheLED will show the phase selected by showing “PH” followed by the phase number. LIGHT — If you wish, you can deactivate the numeric LED on your SC-1250. To do this, pressthe LIGHT button on your remote. To reactivate the LED, press the LIGHT button again.www.velodyne.comSubContractor User’s Manual12

NIGHT — Night mode limits the maximum output of the subwoofer for late night listeningor to be more considerate of close neighbors. Press the night button to turn the nightmode feature on or off. Night mode, when active, will reduce the brightness of the blue LED. VOLUME CONTROL — This control allows you to balance the output from the subwoofer tothe main speakers in your system. This control should be set to achieve similar volume levelfrom between both the main speakers and subwoofer. When pressing volume up or down,the volume level is shown on the numeric LED on the front panel.Note: The volume can also be adjusted via the volume buttons on the front panel of theamplifier. These buttons have the same effect as pressing the up and down volume buttons onyour remote. PRESETS — There are 4 presets, consisting of Movies, R&B – Rock, Jazz – Classical, andGames. As a preset is chosen, the preset is shown on the numeric LED as P1 for preset 1,P2 for preset 2, etc. The presets provide the following characteristics for bass reproduction:Movies:Maximum output and impact for explosions and otheraction adventure movie content.R&B – Rock:Provides the driving bass found in today’s rock music.Jazz – Classical: The tightest, cleanest, lowest distortion bass. The flattest frequencyresponse of the four presets.Games:.Maximum loudness available for the impact of video games.www.velodyne.comSubContractor User’s Manual13

The following table indicates musical style and which preset is recommended for it.MUSICAL STYLEAction Adventure MoviesCountry – RockCountry – SoftFolkIndie MusicPopRockAlternative RockBluesBroadway and VocalistsChildren’s MusicChristian and GospelClassic RockClassicalDance and DJHard Rock/Heavy MetalLatin MusicMiscellaneousMovies– Non-Action AdventureNew AgeOpera and VocalR&BRap and Hip-HopSoundtracksVideo Games.www.velodyne.comSUGGESTED PRESETMoviesR&B – RockJazz – ClassicalJazz – ClassicalR&B – RockR&B – RockR&B – RockJazz – ClassicalJazz – ClassicalJazz – ClassicalJazz – ClassicalJazz – ClassicalR&B – RockJazz – ClassicalR&B – RockR&B – RockR&B – RockJazz – ClassicalJazz – ClassicalJazz – ClassicalJazz – ClassicalR&B – RockR&B – RockR&B – Rock or Jazz– ClassicalGamesSubContractor User’s Manual14

Each preset has its own characteristics with respect to subsonic filter, volume differential anda single equalizer (EQ) in order to optimize the listening mode for the preset.R e s t o r i n g D e fa u l t sThere is a feature that allows you to restore default settings for your SC-1250. By pressingpresets in EXACTLY the following order on the remote, the unit’s power light will blink indicatingthat you have restored tPreset1:2:3:4:4:3:2:1:MoviesR&B – RockJazz – ClassicalGamesGamesJazz – ClassicalR&B – RockMoviesWhen you press the presets in the above order, the numeric LED will display “P3” indicating thatyou have restored defaults. The unit’s volume is reset to level 30 out of 80.C a r e o f yo u r A m p l i f i e r a n d S u b w o o f e rDo not use any harsh detergents or chemicals to clean the SC-1250 chassis or the subwoofercabinet. Abrasives, detergents, or cleaning solutions will damage the finish on the SC-1250chassis or the subwoofer cabinet. We recommend using a damp cloth to clean the front, backand sides.During normal conditions, the amplifier may be left on continuously without any problems. If youplan to leave the unit unused for an extended period of time, we recommend that you turn offthe unit by the master power switch on the front panel.www.velodyne.comSubContractor User’s Manual15

TROUBLESHOOTING AND SERVICEBefore seeking service for your amplifier or subwoofer, please re-check all systems. Followingis a simple troubleshooting guide to assist you.1.2.3.4.5.Verify that the unit is plugged in and power outlet used is active.Is the power switch on?Is the unit receiving an input signal from your source?Have all controls on the amplifier (volume, crossover, phase, etc.) been properly set?If the unit has been running at high levels, one of the protection circuits may be engaged.Has the amplifier overheated?6. Has the power button been depressed on the remote?7. Is the remote non-responsive? We recommend replacing the batteries in the remote.If the protection circuitry is active, the unit may cycle on and off until operating parametersreturn to normal. Under more serious conditions, the unit may shut off completely. Normaloperation should return upon cooling, but you may be required to turn the power off and thenon again to reset the unit.The following conditions require service by a qualified technician:1. The power cord has become damaged2. The unit does not appear to operate normally or exhibits a markedchange in performance3. The unit has been exposed to water4. Some part of the chassis or circuitry is physically damagedThank You for Purchasing an SC-1250!.www.velodyne.comSubContractor User’s Manual16

Specificationswww.velodyne.comSubContractor User’s Manual17

Appendix A: RS-232 Serial Overview and CommandsIntroductionThis document outlines Velodyne’s SubContractor (SC) RS-232 protocol specification. Thisprotocol indicates how SC products receive run-time commands from devices such as CrestonUniversal Remote Controls.Com Port SetupUse standard communications settings: Baud Rate: 9600, Data Bits: 8, Parity: None, StopBits: 1SC IN and OUT Port Pin ConfigurationSC serial ports use a standard configuration that allows direct connection to a PC via a FEMALEto MALE serial cable. It uses only three pins (Transmit, Receive, Ground).The pin configurations are:IN:Pin 2 TransmitPin 3 ReceivePin 5 GroundOUT:Pin 2 ReceivePin 3 TransmitPin 5 GroundRuntime Command Format.Byte NumberByte DescriptionNotes0‘#’Header Character1 to 3 or 4Command andParameter Data3 to 4 ASCII characters see formats belowCase sensitive - CAPS ONLY!4 or 5‘ ’Termination Character (required orcommand is ignored)www.vel

- Oversized spider for linearity at high excursion - High-excursion EPDM rubber surround - 107 ounce magnet/204 ounce motor structure - Frequency Response: 28 - 120 Hz ( /- 3 dB) - 8 ohm impedance SC-10: - 10” (8” piston diameter) subwoofer - 3” high temperature inside/outside voice coil - Oversized spider for linearity at high excursion