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10

7. LEVEL 

The LEVEL control adjusts the overall signal level at 

the input to the built-in power amplifier. It ranges from 
-6 dB to +6 dB (maximum gain), with unity gain at the 
center position (12 o’clock).

The control has no effect on the level of the high-

pass outputs [5] or the full-range outputs [4].

8. THERMAL LED

The SRM1801 is equipped with a thermal protection 

circuit that monitors the internal temperature of the 
amplifiers and heatsink. If the temperature exceeds a 
safe operating level, this indicator lights and the input 
signal is muted to allow the amplifiers to cool. When 
the temperature cools to a safe level once again, the 
thermal protection circuit deactivates, the Thermal 
LED turns off and the SRM1801 returns to normal 
operation. 

When the SRM1801 is in thermal protect mode, the 

power LED [11] will remain lit, indicating that the unit 
is still powered on despite the lack of output.  

Activation of the thermal protection circuit 
is an indication that you should take steps 
to avoid continued thermal problems. See 
“Thermal Protection” on page 12.

9. OL LED

The OL (overload) indicator lights when the 

amplifier in the SRM1801 is near the clipping point. It 
is okay if the OL indicator blinks occasionally, because 
this means that the transient peaks are just reaching 
the maximum output of the amplifier and you are 
getting the most from your SRM1801. 

If the OL indicator is blinking frequently or lighting 

continuously, turn down the LEVEL control [7] on the 
SRM1801 or turn down the signal at it source  
(e.g., the mixing console) until the OL indicator blinks 
occasionally or not at all.

10. SIGNAL LED

This LED illuminates green whenever there is a 

signal present at the main input connector. It senses the 
signal just after the Level control, so adjustments to the 
level control will affect the signal indicator.  

11. POWER LED

This LED illuminates when the power switch [2] is 

turned on and the linecord is connected to an active AC  
Mains supply. 

REVISION

SERIAL NUMBER

WARNING

:

 TO REDUCE THE RISK OF FIRE OR ELECTRIC

SHOCK, DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR
MOISTURE.  DO NOT REMOVE COVER. NO USER SERVICEABLE
PARTS INSIDE. REFER SERVICING TO QUALIFIED PERSONNEL.

AVIS: RISQUE DE CHOC ELECTRIQUE — NE PAS OUVRIR

POWER

I

O

B

A

INPUTS

B

A

B

A

OUTPUTS

HIGH PASS

FULL RANGE

LEVEL

OL

SIGNAL POWER

POLARITY

NORMAL
INVERT

THERMAL

+

6dB

6dB

18-INCH POWERED SOUND REINFORCEMENT SUBWOOFER 

11

8

7

6

5

4

3

9 10

Summary of Contents for SRM1801

Page 1: ...OWNER S MANUAL 18 Powered Subwoofer SRM1801...

Page 2: ...or an experienced radio TV technician for help CAUTION Changes or modifications to this device not expressly approved by LOUD Technologies Inc could void the user s authority to operate the equipment...

Page 3: ...at www mackie com for more information about this and other Mackie products Subwoofer 1 Subwoofer 2 Please write the serial number for your SRM1801 here or for both SRM1801 s if you have two for futu...

Page 4: ...volume control and loudness from the subwoofer Now that you have your subwoofers working it s time to hunker down and read the rest of this manual especially the following ADDITIONAL TIDBITS OF WIDSD...

Page 5: ...hat is ideal for small clubs DJs and rehearsal spaces The SRM1801 has both full range and high pass stereo outputs for connection to full range top boxes Just dial in the appropriate level and use the...

Page 6: ...R POLARITY NORMAL INVERT THERMAL 6dB 6dB REVISION SERIAL NUMBER WARNING TO REDUCETHE RISK OF FIRE OR ELECTRIC SHOCK DO NOT EXPOSE THIS EQUIPMENTTO RAIN OR MOISTURE DO NOT REMOVE COVER NO USER SERVICEA...

Page 7: ...UIPMENTTO RAIN OR MOISTURE DO NOT REMOVE COVER NO USER SERVICEABLE PARTS INSIDE REFER SERVICINGTO QUALIFIED PERSONNEL AVIS RISQUE DE CHOC ELECTRIQUE NE PAS OUVRIR B A INPUTS B A B A OUTPUTS HIGH PASS...

Page 8: ...n off thumps in your speakers The rear panel is where you connect AC power and your signals to and from the subwoofer You may also adjust the level and polarity to match the other loudspeakers in your...

Page 9: ...t powers the subwoofer The frequency range above 125 Hz is sent to these line level output jacks Connect these outputs to the inputs of your main powered loudspeakers or to the inputs of the amplifier...

Page 10: ...tor lights when the amplifier in the SRM1801 is near the clipping point It is okay if the OL indicator blinks occasionally because this means that the transient peaks are just reaching the maximum out...

Page 11: ...sition especially if you are listening to just the subwoofer This is normal as our ears perceive them both as the same The polarity invert switch comes into play when the SRM1801 subwoofer is paired w...

Page 12: ...esigned to protect the subwoofers under reasonable and sensible conditions Should you choose to ignore the warning signs i e frequent OL LED indications excessive distortion you can still damage the s...

Page 13: ...al source turned up Make sure the signal level from the mixing console or whatever device immediately precedes the subwoofer is high enough to produce sound If it s a stereo pair try switching them ar...

Page 14: ...g a ground loop If connecting an unbalanced output to the SRM1801 balanced input make sure the shield is connected to the unbalanced ground and to pin 1 of the XLR Repair For warranty service refer to...

Page 15: ...abeled FULL RANGE and two labled HIGH PASS These are also wired according to the AES standards listed above The FULL RANGE connectors allow you to connect several SRM1801 s Simply plug the signal sour...

Page 16: ...Technologies Inc All other brand names mentioned are trademarks or registered trademarks of their respective holders and are hereby acknowledged 2011 LOUD Technologies Inc All Rights Reserved Acousti...

Page 17: ...25 3 in 643 mm 20 2 in 513 mm WEIGHT 73 lb 33 1 kg 15 1 in 383 mm 18 INCH POWERED SOUND REINFORCEMENT SUBWOOFER SRM1801 Dimensions SRM1801 Frequency Response 1 3 Octave Response Normalized to 0 dB SPL...

Page 18: ...ded by the distributor in your local market LOUD warrants to Customer that the product will be free from defects in materials and workmanship under normal use during the Warranty Period If the product...

Page 19: ...Road NE Woodinville WA 98072 USA United States and Canada 800 898 3211 Europe Asia Central and South America 425 487 4333 Middle East and Africa 31 20 654 4000 Fax 425 487 4337 www mackie com E mail s...

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