® THX powered subwoofers operation manual MX-5000THX Mk II MX-350THX Miller & Kreisel Sound Corporation 10391 Jefferson Boulevard Culver City, CA 90232 USA (310) 204-2854 FAX (310) 202-8782 © 1997 MILLER & KREISEL SOUND CORP. Manufactured under license from Lucasfilm Ltd. Lucasfilm and THX are registered trademarks of Lucasfilm Ltd.
THX subwoofers page 2 TABLE OF CONTENTS 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. SAFETY INSTRUCTIONS ................................................................................................ 3 INTRODUCTION .............................................................................................................. 4 WHERE TO PLACE YOUR SUBWOOFER ..................................................................... 4 OPERATION WITH THX COMPONENTS...............................................
THX subwoofers page 3 CAUTION RISK OF ELECTRIC SHOCK DO NOT OPEN The lightning flash with arrowhead, within an equilateral triangle, is intended to alert the user of the presence of uninsulated "dangerous voltage" within the product's enclosure that may be of sufficient magnitude to constitute a risk of electric shock to persons. CAUTION: TO PREVENT THE RISK OF ELECTRIC SHOCK, DO NOT REMOVE COVER (OR BACK). NO USER-SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.
THX subwoofers page 4 2. INTRODUCTION Congratulations! Your new M&K THX® subwoofer truly represents the state-of-the-art in subwoofer performance. The new dimension of deep and powerful bass it provides will both thrill and excite you. We strongly encourage you to read this owner's manual, as there is a great deal of information provided here to help you get the best possible performance.
THX subwoofers page 5 To connect the subwoofer, run a shielded RCA - RCA interconnect cable from the SUBWOOFER OUTPUT jack on your THX controller to the "LEFT/MONO" "INPUT" jack on the subwoofer's backplate. See Figure 1 below. Some THX controllers have a pair of stereo subwoofer outputs, while others have a single mono output. Your subwoofer is compatible with both types.
THX subwoofers page 6 to the Left subwoofer and the Right cable to the Right subwoofer. See Figure 2 on page 5. TESTING THE SUBWOOFER (THX MODE) Once all of the interconnect cables are in place, you are just about ready to plug in the subwoofer. Set the "LOW PASS FILTER" toggle switch to the "THX MODE" position. Set the "BASS LEVEL" toggle switch to the "THX" position. Set the "BASS EQ" toggle switch to the "THX" position. Set the "PHASE" switch to the "+" position.
THX subwoofers page 7 and it gives you maximum output level, dynamic range, and headroom. In your listening room, the "ANECHOIC" position will actually produce a rising output below about 30 Hz. Its response is not as flat (accurate) as the "THX" position and it limits the subwoofer's maximum output and dynamic range. For performance to THX specifications, this switch must be set to the "THX" position.
THX subwoofers page 8 knob sets the upper rolloff point of the Subwoofer, eliminating mid-bass and midrange that are being reproduced by your Satellite speakers. The control is a means of fine-tuning the transition between your Subwoofer and Satellite speakers, and it provides a rolloff of 12 dB/octave up to 125 Hz, where the filter shifts to 36 dB/octave. The frequency where the rolloff begins is labelled on the back panel. In most systems, including M&K Satellites, about 80 Hz gives the best blend.
THX subwoofers page 9 FIGURE 3 - WIRING ONE SUBWOOFER TO AN AMP OR PROCESSOR WITH A SUBWOOFER OUTPUT JACK (NON-THX) LOW PASS FILTER THX MODE V A R I A 06 B L E SUBWOOFER (or MONO) OUT NO LOW PASS FILTER 57 05 521 RIGHT THX THX INPUT 80 Hz 24 dB/ OCTAVE CENTER SWITCH POSITION FOR VARIABLE LOW PASS SURROUND PROCESSOR BASS LEVEL BASS EQ PHASE + LEFT/MONO 01 REFERENCE +3 dB +6 dB EXTENDED VARIABLE MX-350THX POWERED SUBWOOFER Manufactured under license from Lucasfilm Ltd.
THX subwoofers page 10 FIGURE 5 - WIRING ONE SUBWOOFER TO AN AMP OR PREAMP WITH ONE SET OF PREAMP OUTPUTS POWER AMP MAIN IN LEFT LOW PASS FILTER THX MODE RIGHT V A R I A 06 B L E LEFT PREAMP NO LOW PASS FILTER 57 521 05 THX RIGHT THX INPUT 80 Hz 24 dB/ OCTAVE CENTER SWITCH POSITION FOR VARIABLE LOW PASS RIGHT BASS LEVEL BASS EQ PHASE + LEFT/MONO 01 REFERENCE +3 dB +6 dB EXTENDED VARIABLE MX-350THX POWERED SUBWOOFER Manufactured under license from Lucasfilm Ltd.
THX subwoofers page 11 to feed these filters. To connect one of these filters, run one set of shielded RCA - RCA interconnect cables from the receiver, amp or preamp's MAIN OUTPUT to the input jacks on the HP-80 or VF-80. Run another set of interconnects from the high frequency output jacks on the filter to receiver or amp's POWER AMP inputs. Last, run interconnects from the subwoofer output jacks to the subwoofer's "INPUT" jacks. See the instructions enclosed with your filter for wiring diagrams.
THX subwoofers page 12 an additional total of 6 dB of output. Wiring with two subwoofers is simple. Instead of running two interconnect cables to one subwoofer, just run one interconnect to each subwoofer, using the "LEFT/MONO INPUT" jack on each subwoofer. You don't need a Y-connector. See Figure 4 (page 9), or Figure 6 (page 10). 7. SATELLITE/SUBWOOFER PHASING TEST (WITH BOTH THX AND NON-THX COMPONENTS) Before you can sit down to enjoy your new subwoofer, you need to perform one simple Phasing Test.
THX subwoofers page 13 output. When this happens, the midbass is cancelled. Re-do this test any time you move any of your speakers or the listening position. If you want to experiment, move the main speakers or subwoofer towards or away from your listening position, in small increments. When you hear the best combination of stereo image localization and focus with solid midbass impact and output, you have the ideal location. If you have two subwoofers, perform one test for each subwoofer.
THX subwoofers page 14 Buzzes and rattles can be cured or improved by applying glue, tape, or pads in the area where the objects are vibrating against each other. Try felt pads between objects that cannot be taped or glued together (such as picture frames buzzing against walls). One subwoofer is sufficient in a stereo system because the human ear-brain hearing system cannot ocate the direction of bass sounds below 150 Hz.
THX subwoofers page 15 e. If the red LED is still lit, set the "BASS LEVEL" switch to the "VARIABLE" position. Turn the "BASS LEVEL" control to "MIN". Plug a standard RCA cable into the "LEFT/MONO" "FROM PREAMP" jacks. Lightly touch the plug at the free end of the cable. Then turn the "BASS LEVEL" control clockwise. If you hear a buzz or hum from the subwoofer when you touch the cable, the subwoofer is working. Look elsewhere in your system for the problem.
THX subwoofers page 16 REPLACEMENT FUSE VALUES 110 VOLT 220 VOLT 220 VOLT (U. S.) (U. S.) (IEC 127-2/III) MX-5000 Mk II 7.0 amp 3AG 4.0 amp 3AG External 1/4" x 1 1/4" slow-blow 1/4" x 1 1/4" slow-blow T 3.15 A 5 x 20 mm time-lag MX-350 External T 3.15 A 5 x 20 mm time-lag 6.0 amp 3AG 3.0 amp 3AG 1/4" x 1 1/4" slow-blow 1/4" x 1 1/4" slow-blow MX-5000 Mk II internal: MX-350 internal: All versions use 8.0 amp 3AG 1/4" x 1 1/4" fast-blow fuse All versions use 7.
