Go To Bulletins SRM450 Powered Speaker SERVICE MANUAL 1999,2000 MACKIE DESIGNS, INC.
SERVICE ON THIS EQUIPMENT IS TO BE PERFORMED BY EXPERIENCED REPAIR TECHNICIANS ONLY 2
CONTENTS Introduction ..................................................................... 3 Block diagram .................................................................. 4 Specifications ................................................................... 5 Overview .......................................................................... 6 Safety test ........................................................................ 8 Bias adjustment .............................................................
THRU INPUT 1 1 SIGNAL SENSE TIMED TURNOFF + LO VDC Ð + MID VDC Ð HI-PASS HI-FREQ COMPRESSOR THRESHOLD 176uS LPF THRESHOLD 40-120 Hz DELAY LO-PASSCOMPRESSOR + HI VDC Ð SWEEPING FILTER MUTE THERMAL POWER LED LEDS CONTOUR MUTE ON/OFF LOW AC VOLTS SENSE CONTROL THERMAL SWITCH LOW CUT TOROIDAL POWER TRANSFORMER POWER SWITCH ON OFF FUSE +15VDC SIGNAL SENSE SIGNAL LED J15 Block Diagram PEAK LIGHT TWEET SENSE RESISTOR WOOF LO-FREQUENCY DRIVER PEAK DETECTION BASS CONTROL SER
Specifications Low-Frequency Transducer System specs Diameter Voice Coil Diameter Sensitivity (1W@1m) Nominal Impedance Power Handling Frequency Range Input Type Input Impedance Input Protection Sensitivity 300mm (12”) 63.5mm (2.5”) 98 dB 8 ohms 300W 50Hz – 3000Hz High-Freq Driver and Horn Diaphragm Diameter Exit Throat Diameter Diaphragm Material Sensitivity (1W@1m) Nominal Impedance Power Handling Frequency Range 44.5mm (1.75”) 24.
Overview The SRM450 is an active two-way loudspeaker system capable of extremely high sound pressure levels. The Transducers The SRM450 active monitors feature a 12” high-power low-frequency woofer and a 1.75” titanium diaphragm high-output precision compression driver. This high frequency driver is mounted on an acoustically non-resonant exponential waveguide, providing a wide, controlled dispersion and precise reproduction of the critical upper mid-range and high frequencies.
The Crossover The built-in electronic crossover is a 24 dB/octave Linkwitz-Riley design. Although more expensive than other crossover designs, the benefits provided by the Linkwitz-Riley design have been well documented. These benefits include: • Absolutely flat frequency response throughout the bandpass, without the characteristic ripple near the crossover point exhibited by other designs.
Safety test You must perform the following leakage test before returning the unit to your customer. Take every safety precaution to protect yourself while doing this test. 1. Make a small loading RC circuit as shown in the diagram below, and connect the AC volt meter between the AC power source ground and any exposed metal on the unit under test. 2. Connect the unit under test to an AC power source using a ground-lift adaptor, leaving the unit’s safety ground floating. Turn the unit on. 3.
Bias adjustment The Amplifier Bias of every SRM450 must be carefully adjusted as follows. 1. Place the SRM450 on its side so that the heatsink fins are horizontal. 2. Connect the power cord and turn it on, with no input signal applied. Make sure that the TIMED TURNOFF switch is OFF. 3. Let it sit this way for an hour or more to allow the heatsink temperature to rise. You can play music through to speed things up.
HIGH FREQUENCY BIAS ADJUSTMENT POT LOW FREQUENCY BIAS TEST POINT HIGH FREQUENCY BIAS TEST POINT LOW FREQUENCY BIAS ADJUSTMENT POT +15 VDC -15 VDC +80V -80V +45V -45V
SRM-450 PARTS LIST Parts 040055100200300400500510550600601610640700760770790800860- Numbering guide Cables Finished PCB Assy Pots and resistors Capacitors Semiconductors Jacks/Connectors Switches Fuses Chassis Metalwork Transformers Inductors Wires and Cables AC line cords Hardware Knobs/Plastic Fans Misc.
247b Master Parts List 090-132-xx PART NO.
Cabinet Subassembly 080-136-00 PART NO.
227c 055-227-00 Main pcb assembly PART NO. DESCRIPTION VALUE 040-311-00 100-084-00 105-464-00 110-025-00 115-361-00 115-364-00 115-389-00 115-418-00 120-097-00 122-081-00 123-009-00 123-056-00 125-030-00 130-021-00 130-038-00 130-078-02 140-025-00 140-042-00 140-049-00 140-066-00 140-073-00 140-080-00 140-097-00 140-112-00 140-115-00 140-119-00 140-123-00 140-147-00 145-162-00 DIS 18GA 1010 GNYL 5 HKLG RES CF .125W 5% 30K OHM RES MF .125W 1% 60K4 OHM RES CF .25W 5% 100 OHM RES MF .
227c PART NO. DESCRIPTION VALUE REFERENCE DESIGNATORS 145-358-00 145-361-00 RES MF SM .1W 1% 4K75 OHM RES MF SM .1W 1% 5K11 OHM 4K75 5K11 1% 1% 145-369-00 145-371-00 145-373-00 145-375-00 145-377-00 145-381-00 145-384-00 145-389-00 RES MF SM .1W 1% 6K19 OHM RES MF SM .1W 1% 6K49 OHM RES MF SM .1W 1% 6K81 OHM RES MF SM .1W 1% 7K32 OHM RES MF SM .1W 1% 7K50 OHM RES MF SM .1W 1% 8K25 OHM RES MF SM .1W 1% 8K87 OHM RES MF SM .
227c PART NO. DESCRIPTION VALUE REFERENCE DESIGNATORS 200-004-02 200-023-00 200-024-00 200-027-02 PLY .047UF 10% 100V TR PLY/BX .001UF 20% 250V Y2 PLY/BX .01UF 20% 250V Y2 PLY .1UF 5% 100V TR 0.047 .001uF .01uF 0.1 10% 20% 20% 5% 200-041-00 200-042-02 205-001-02 205-002-02 212-001-00 PLY/FL .01UF 10% 250V PLY/BX .22UF 10%250V TR MICA 180PF 5% 500V T/A MICA 270PF 5% 500V TR CER .01UF 10% 50V X7R SM 0.01 0.22 180pF 270pF 0.
227c PART NO.
SRM450 Bias Adjustment, sheet 1 of 2 Model: SRM450 Active Speaker Serial Number: ALL Effective: June 1999 Problem: The Amplifier Bias of every SRM450 must be carefully adjusted as follows. Procedure: 1. Place the SRM450 on its side so that the heatsink fins are horizontal. 2. Connect the power cord and turn it on, with no input signal applied. Make sure that the TIMED TURNOFF switch is OFF. 3. Let it sit this way for an hour or more to allow the heatsink temperature to rise.
HIGH FREQUENCY BIAS ADJUSTMENT POT LOW FREQUENCY BIAS TEST POINT HIGH FREQUENCY BIAS TEST POINT LOW FREQUENCY BIAS ADJUSTMENT POT +15 VDC -15 VDC +80V -80V +45V -45V THE MACKIE FIXER MACKIE DESIGNS SERVICE NEWS SRM450 Bias Adjustment, sheet 2 of 2 SRM450 Bias SSE June 1999
Description Initial Release Rev A Date SRM450 Pole Mount Insert Rework Instructions 851-033-00 REV A Prepared by: ______________________________Date: _____________ Chad Trani Manufacturing Engineer Approved by: ______________________________Date: _____________ Ray Vancour Field Service Manager Approved by: ______________________________Date: _____________ John Ray Quality Assurance Manager
SRM450 Pole Mount Insert Rework Instructions Note: These instructions are to be used along with Mackie kit P/N 020-006-00 to repair SRM450s which already have the pole mount insert stripped out. The pole mount bolt assembly (bolt, knurled brass insert and alignment bushing) must still be with the unit as the parts will be recycled and also used during the rework. 1) Remove stripped out pole mount bolt assembly. This can be done by hand – one or two sharp jerks on the bolt should pull the assembly free.
Installation Tool Assembly Insert Installation 6) Place the tool (insert first) into the pole mount hole. 7) Using the small pipe, gently tap the bushing into place so it fits snug. The bushing only needs to be partially installed (as a guide) since it will be removed shortly. Remove the pipe. Tapping bushing into place with pipe 8) Attach drill or similar device to insert tool and drive insert into position clockwise. Insert will stop against shoulder when at correct installed depth.
9) Reverse the drill and back the tool out. A quick, sharp twist once you start to back the tool out will break the tool free from the insert. You do not need to remove the tool slowly as with the installation. The metal bushing will easily pull out along with the installation tool. 10) Using a small flathead screwdriver or similar tool, remove the plastic chips from inside the pole mount hole on the bottom of the speaker.
SRM450/C300 stabilizing feet 1 2 3 ©2000 Mackie Designs Inc. All rights reserved The following are trademarks or registered trademarks of Mackie Designs Inc.: “Mackie” and the “Running man” figure. Part No. 820-158-01 Rev A 8/2000 SRM450/C300 stabilizing feet 1 2 3 ©2000 Mackie Designs Inc. All rights reserved The following are trademarks or registered trademarks of Mackie Designs Inc.: “Mackie” and the “Running man” figure. Part No.
