Operation Manual
www.velodyne.com
10 - SC-1250 Amplier User’s Manual
You should set the crossover frequency to obtain a smooth and seamless transition from the subwoofer(s) to
the main speakers in your system. If your main speakers are smaller units with limited low frequency output,
youmaywishtochooseahigherfrequency(suchas100-120Hz)thanyouwouldwithlargerspeakerswhich
have greater low frequency output. With larger speakers, you might start with this control set lower, such as 80
Hz.TheSC-1250crossoverhasadefaultof80Hz.
Mostreceivers and processorsprovidean option tocharacterizemain speakers as“large”or“small.” This
aectsthecrossoverpoint.Werecommendinmostcasessettingthemainspeakersto“small,”despitetheir
sizeandfrequencyresponsecharacteristics.Thisisbecausethepowerful1250wattSC-1250combinedwith
the SC subwoofer(s) you have acquired are more than likely more suited to low bass reproduction than your
ampandmainspeakercombination.Withtheburdenoflowfrequencyreproductionrelieved,youramplierand
mainspeakercombinationwillenjoybetterperformanceandabout50%moreavailableheadroom,enabling
them to more accurately reproduce the rest of the frequency spectrum.
Disabling the Low-Pass Crossover (Subwoofer Direct)
Ifyourreceiver/processorprovidesacrossovertothesubwoofer(s),youmaywanttobypasstheSC-1250’s
low-passcrossover.Todothis,depressBOTHtheCrossoverUPandCrossoverDOWNbuttonssimultaneously.
The numeric LED will show indicating that the low-pass crossover has been defeated. To reactivate the low-
pass crossover, simply push the crossover UP or crossover DOWN buttons.
A Word About Your Receiver’s Crossover and the SC-1250 Crossover
YourVelodyneSC-1250amplierisdesignedtooperateusingthefullrangeaudiosignalforinputwhenusingthe
built-incrossover.Manyhometheaterprocessors/receivers(DolbyDigital
®
, DTS
®
,THX™)havea“subwoofer
out”jackthatperformsthissamefunctionandaredesignedtobeusedwithapoweredsubwoofer.
In these installations, you may want to bypass the crossover in either the processor or the Velodyne SC-1250
asdescribedabove.However,insomecasesyoumaywanttouseBOTHcrossovers.Ifyouchoosetodothis
youshouldstaggerthefrequencies,(i.e.,120Hzsubwoofer,80Hzprocessor)forbestresults.
Note: If not using an external crossover, you should use the built-in crossover for optimal performance. When
usingasingleRCAsuboutfromtheprocessor,itdoesnotmatterwhichlinelevelinput(L/R)isused.
A Word About Interconnect Cables
When installing your Velodyne SC-1250 using the line-level connections, you should always use high quality
shielded interconnect cables. It is recommended that you keep the length of cable as short as possible to avoid
any potential external interference problems.
WhenconnectingtheSC-1250toyoursubwoofer(s),useaqualityspeakercablethatisatleast14-gauge.Be
very careful to avoid any loose or frayed strands that could result in a short, causing a dangerous condition and
possibledamagetoyourunit.Cablesofextremelylargesizearetypicallynotrequired.Extremelylargegauge
wiremaynotproperlytinthebindingposts,resultinginapoorconnectionandpossibleshortcircuits.