Owner’s Manual SF-1 Subwoofer Filter FPO Rev.
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SF-1 SUBWOOFER FILTER INTRODUCTION The SF-1 Subwoofer Filter is an upper slot accessory for QSC MXa Series amplifiers, which feature Level One Open Input Architecture. The accessory mounts in the back of the amplifier above the standard input panel. Ideal for adding subwoofer amplification to an existing full-range system, the SF-1 offers adjustable and selectable low-pass filtering for both channels of the amplifier, in addition to adjustable high-pass subsonic filtering.
CONFIGURATION SETTING THE SUBSONIC FILTER FREQUENCY The subsonic (highpass) filter on Channel 1 cannot be bypassed, and Channel 2 should only be bypassed in the bridged mono mode. Plug-in SIP resistor network RN3 sets the high-pass frequency for both channels 1 and 2. Table 2 shows the resistor value to be used for the frequency you desire. Typical subsonic frequencies available with the provided SIP resistor networks are 20, 25, 32, 35, 40, 50, 63, and 80 Hz.
• Stereo, Bridged Mono, and Parallel Mono If the two subwoofer channels are to carry different or independent program material, as in stereo or bridged mono, set the SF-1 for “Stereo” operation. Use this also for parallel mono operation from a single program signal source.
INSTALLATION Before installing the SF-1, disconnect the amplifier’s power cable from the AC mains. 1. Position the amplifier so that the rear panel is facing you. Locate the input panel and the blank accessory panel above it. 2. Remove the four mounting screws—the two holding the blank panel and the two holding the standard input panel. Remove the blank panel (which the SF-1 will replace) and carefully pull the input panel out from the amplifier chassis (figure 2a). 3.
SPECIFICATIONS SIGNAL TO NOISE RATIO (22 Hz to 22 kHz): 103 dB TOTAL HARMONIC DISTORTION <0.1 % CROSSTALK 70 dB below rated power within passband CMRR: better than 50 dB FILTER TYPE second-order butterworth, Q=0.
APPLICATION NOTES For cinema surround channels and subwoofers that do not require an EQ boost, use the following switch settings.
APPENDIX A: WARRANTY & DISCLAIMERS DISCLAIMER QSC Audio Products, Inc. is not liable for any damage to speakers, amplifiers, or any other equipment that is caused by negligence or improper installation and/or use of the SF-1 Subwoofer Filter. PRODUCT WARRANTY QSC Audio Products, Inc.
QSC TECHNICAL SERVICES DEPARTMENT 1675 MacArthur Blvd Costa Mesa, CA 92626 Telephone: (800) 772-2834 (714) 957-7150 (714) 754-6175 Fax: (714) 754-6173 Bulletin Board: (714) 668-7567 (800) 856-6003 INTERNATIONAL SERVICING For QSC products that are purchased outside of the United States, service must be referred to the distributor or dealer from where the product was purchased. There are numerous service centers in many countries.
QSC AUDIO PRODUCTS, INC. 1675 MacArthur Blvd., Costa Mesa, CA 92626 USA Ph (714) 754-6175 Fax (714) 754-6174 Email INFO@qscaudio.com Web http://www.qscaudio.com “QSC” and the QSC logo are registered with the U.S. Patent and Trademark Office.
