2
LS4
24dB/Octave Active Stereo Crossover
Congratulations
on the purchase of your new Crate Pro Audio LS4 Crossover. This outstanding device
has been designed with the audio professional in mind, providing the degree of accuracy and level of qual-
ity you demand. Its straight-forward design and simple operation make it easy to use by novices as well.
This owner’s guide is designed to acquaint you with the workings of the crossover and how it may be used
in your sound system and should be read through before using the unit.
Introduction:
Crate’s new LS4 is a rugged multi-purpose active crossover housed in a standard 19” single space rack
enclosure. It features pushbutton selectable two-way stereo or three-way mono operation. All inputs and
outputs are balanced for low noise operation. Each channel features parallel inputs for “daisy-chaining” two
or more units together.
The new LS4 features two Linkwitz-Riley state variable filters that include 24dB/octave slopes and a low “Q”
design for minimal ringing. Each output is in phase at the crossover point, which eliminates the need for
polarity reversal between components. The LS4 also features a 40Hz low cut filter for subsonic filtering and
a 15kHz high cut filter for reduction of hiss. The output level controls provide 6dB boost at full rotation for
weak input signals. The crossover frequency is continuously variable with between 50Hz and 1kHz or
500Hz and 10kHz. The CD Horn Equalizer switch is a special feature. This switch, when engaged, provides
a boost in the higher frequencies to compensate for the high frequency deficiencies in Constant-Directivity
horns. The inputs are both XLR and 1/4” TRS and can be used as either balanced or unbalanced inputs. All
of the outputs are 1/4” TRS jacks and can also be used either balanced or unbalanced.
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK,
DO NOT REMOVE COVER.
NO USER-SERVICEABLE PARTS INSIDE.
REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.
ATTENTION
RISQUE D'ELECTROCUTION
NE PAS OUVRIR
ATTENTION: POUR REDUIRE D'ELECTROCUTION NE PAS
ENLEVER LE COUVERCLE. AUCUNE PIECE INTERNE N'EST REPRABLE
PAR L'UTILISATEUR. POUR TOUTE REPARATION, S'ADRESSER A UN
TECHNICIEN QUALIFIE.
VORSICHT
ELEKTRISCHE SCHLAGGEFAHR
NICHT OFFENEN
VORSICHT: ZUR MINIMIERUNG ELEKTRISCHER SCHLAGGEFAHR NICHT
DEN DECKEL ABENHMEN. INTERNE TEILE KONNEN NICHT VOM
BENUTZER GEWARTET WERDEN. DIE WARTUNG IS QUALIFIZIERTEM
WARTUNGSPERSONAL ZU UBERLASSEN.
THIS EQUIPMENT HAS BEEN DESIGNED AND ENGINEERED TO PROVIDE SAFE AND RELIABLE OPERATION. IN ORDER TO PROLONG THE
LIFE OF THE UNIT AND PREVENT ACCIDENTAL DAMAGES OR INJURY, PLEASE FOLLOW THESE PRECAUTIONARY GUIDELINES:
CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK, DO NOT OPEN CHASSIS; DO NOT DEFEAT OR REMOVE THE GROUND PIN OF THE
POWER CORD; CONNECT ONLY TO A PROPERLY GROUNDED AC POWER OUTLET.
WARNING: TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK, DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE.
CAUTION: NO USER-SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.
"IT IS NECESSARY FOR THE USER TO REFER TO THE INSTRUCTION MANUAL"
"REFERREZ-VOUS AU MANUAL D'UTILISATION"
"UNBEDINGT IN DER BEDIENUNGSANLEITUNG NACHSCHLAGEN"
EXPLANATION OF
GRAPHICAL SYMBOLS:
"DANGEROUS VOLTAGE"
"DANGER HAUTE TENSION"
"GEFAHLICHE SPANNUNG"
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Table of Contents:
Introduction ..................................................................................2
The Front Panel.............................................................................3
The Rear Panel..............................................................................4
The Low Cut and High Cut Switches ............................................5
The X1/X10 Switch .......................................................................5
The CD Horn EQ Switch...............................................................6
How to Use the Crossover:
With a Subwoofer .............................................................6
For Bi-Amping in a Single Enclosure .................................9
For Tri-Amping ................................................................11
Technical Specifications .....................................back cover
