Mackie SRM150 Compact Active PA System

Introduction

Thank you for choosing a Mackie compact active PA system for your sound reinforcement applications. The SRM150 is an active PA system that provides a built-in mixer, high sound pressure levels, and is designed to give you the best performance of any compact PA system in its class and price range.

Mackie's design goal was to build a compact PA system with:

• High precision, high output, and accurate playback.
• Controlled, smooth dispersion of mid and high frequencies.
• Ultra-clean, high-headroom mic preamps.
• High-output Class-D amplification.
• Onboard Mackie mixer with 3-band EQ.

Through the combined resources of their engineers, Mackie achieved these design goals, resulting in a sound reinforcement PA system equally at home in a concert setting, in the studio, or for impromptu concerts.

The Transducer

The SRM150 active loudspeaker features a full-range 5.25-inch neodymium driver.

Power Amplifier

Each SRM150 includes a Class-D power amplifier capable of producing 150 watts peak before clipping. The amplifier produces up to 100 watts RMS continuous before clipping. A built-in limiter acts when the input signal is large enough to cause clipping, distortion, and excessive voice coil heat. The limiter automatically decreases the signal to a safe level. However, users must still ensure they do not overdrive the amplifier by turning down input gain or main level controls if distortion is heard.

The Cabinet

The SRM150 cabinet is constructed from a strong molded composite material. It features a bottom insert for mic stand mounting and a threaded insert on top for mounting a microphone boom. Its light weight and durable finish make it ideal for portable use, and its design allows it to function as a floor wedge for stage monitor applications.

The Active Advantage

Active speaker systems offer several advantages over passive loudspeakers:

• Amplifiers are specifically designed for the speaker load impedance, maximizing acoustic output and minimizing the risk of speaker damage.
• Minimal connecting wires between the amplifier output and the driver ensure a high damping factor and efficient power transfer without speaker cable losses.
• Active circuits allow for integrated features like a high-quality mic/line input section.

All components are designed to work in harmony for optimal sound performance.

Quick Start

Follow these steps for initial setup:

1. Initial Settings:
   • Front Panel: Set MAIN LEVEL [6] control down. PHANTOM POWER [5] switch out (unless using condenser mics). INSTRUMENT [4] switch out (unless connecting an electric guitar to channel 1). Channels 1-3 gain [3] controls down. EQ [7] controls centered.
   • Rear Panel: Turn the POWER [8] switch off (down). Set MIC/LINE [12] switch out.
2. Connect Signal Source: Connect your signal source (mixer, microphone, preamp, etc.) to the MIC/LINE [1] combo connector on the front. Channel 3 also has stereo RCA jacks [2] for line-level input from devices like CD or MP3 players.
3. Connect Power: Connect the supplied AC power cord to the AC power receptacle [10] on the rear and plug into a properly configured AC outlet (the SRM150 has a universal power supply accepting 100-240V).
4. Turn on Signal Source: Ensure its Master Volume is down.
5. Turn on SRM150: Flip the POWER [8] switch up.
6. Start Signal Source: Begin playback or speaking. Adjust source volume controls as needed.
7. Adjust Main Level: Turn up the MAIN LEVEL [6] control to approximately halfway (12 o'clock).
8. Adjust Gain: Slowly turn up the gain [3] controls for the input channels until the desired volume is reached.
9. Adjust Volume: If too loud, turn down the MAIN LEVEL or source volume. If not loud enough, turn up the MAIN LEVEL or source volume.
10. Troubleshoot No Sound: If no sound, turn down the MAIN LEVEL control before investigating potential issues like muted channels or off switches.

WARNING: Always turn the MAIN LEVEL [6] control down (counterclockwise) before each use to avoid startling surprises, especially when switching between microphone and line-level sources.

Hookup Diagrams

The following diagrams illustrate various setup configurations:

• Practice Setup Using Mic Stand and Boom: Shows the SRM150 mounted on a microphone stand with a boom extender for a microphone. Connections include a vocal mic and electric guitar to channels 1 and 2, and an MP3 player to channel 3.
• Small Club Setup with SRM450: Depicts the SRM150 used as a personal monitor alongside an SRM450 as the main PA speaker, connected via the THRU Out.
• Two SRM150s: Stereo Monitoring: Illustrates two SRM150s used as floor monitors to provide a stereo monitor mix for a keyboard player, connected to a mixer.
• SRM150: A/V Cart: Shows the SRM150 connected to a TV monitor and DVD player for audio playback.

Front Panel Description

Most connections and controls are on the front panel for easy access.

1. MIC/LINE Inputs (Channels 1 & 2)

These combo connectors accept balanced microphone inputs via XLR or balanced/unbalanced line-level inputs via 1/4" TRS or TS connectors. XLR inputs are wired: Pin 1 (Shield), Pin 2 (Hot/+), Pin 3 (Cold/-). 1/4" inputs are wired: Sleeve (Shield), Tip (Hot/+), Ring (Cold/-).

2. Stereo Input (Channel 3)

Channel 3 features RCA connectors for a stereo line-level input from devices like CD or MP3 players.

3. Channel Gain Controls

Adjust the signal level for each channel. Mackie's low-noise mic preamp technology allows connection of mic- or line-level signals. For typical use, set around 12 o'clock. Adjust lower for high-level signals (around 9 o'clock) and higher for low-level or mic signals (around 3 o'clock).

4. INSTRUMENT Switch (CH 1)

This button toggles the 1/4" input on channel 1. When out, it accepts normal line-level signals (low-impedance). When pushed in, it acts as a high-impedance instrument input, suitable for electric guitars without a DI box. Note: For long cable runs (over 20 feet) with instruments, a DI box with a balanced output is recommended to avoid noise pickup.

5. 48V PHANTOM POWER Switch and Indicator

Provides 48V DC to the XLR microphone inputs (channels 1 & 2) for condenser microphones. Push the button to engage; an LED indicates when active. Dynamic microphones do not require phantom power and are generally unaffected, but caution is advised with older ribbon microphones.

6. MAIN LEVEL

Adjusts the overall signal level sent to the built-in power amplifier.

7. HIGH, MID, and LOW EQ

These controls provide up to +/-15 dB of boost or cut for tone shaping:

• HIGH EQ: Affects frequencies above 12 kHz (e.g., cymbals, guitar edge, vocal harmonics). Boost brightens sound.
• MID EQ: Affects frequencies around 2.5 kHz (e.g., vocals). Useful for bringing vocals forward or back in the mix.
• LOW EQ: Affects frequencies below 100 Hz (e.g., bass drums, bass guitar, male vocals). Affects punch and low-end presence.

Rear Panel Description

8. POWER Switch

Toggles power ON (up) or OFF (down). Pressing the bottom puts the unit in standby mode. Ensure MAIN LEVEL [6] is down before turning on. A blue LED on the front indicates power is active.

9. FUSE

A resettable circuit breaker that monitors current draw. It should not pop under normal conditions. To reset: turn POWER [8] off, push FUSE switch UP, then turn POWER back on. If it pops again, refer to the Repair section.

10. AC Power Receptacle

A standard 3-prong IEC connector for the detachable line cord. The SRM150 features a universal power supply (100-240 VAC).

11. THRU Connector

A male XLR connector outputting the main signal before EQ [7] and MAIN LEVEL [6] controls. It carries input signals from channels 1-3 [1/2] and the MAIN IN [13]. Useful for patching to other speakers or mixers.

12. MIC/LINE Switch

This switch affects the THRU connector's output level. Leave OUT (LINE) for line-level connections. Push IN (MIC) for microphone-level connections to mixers or stage snakes.

13. MAIN IN

A combo connector accepting a balanced line-level signal via XLR or 1/4" TRS. This signal is mixed into the main bus before the THRU output, EQ, and MAIN LEVEL controls.

Placement

The SRM150 is designed for floor, tabletop, or microphone stand placement.

• Floor Monitor: Angle it back on the floor for optimal aiming towards performers.
• Microphone Stand: Use the included Mic Stand Adapter to mount it on a standard stand.
• Boom Mounting: The top threaded insert accepts the included Boom Extender for microphone placement.

Placement Tips:

• Avoid placing loudspeakers in corners to prevent muddy low-frequency output.
• Avoid placing loudspeakers directly against walls, as this can increase low-frequency output.
• Avoid placing the active loudspeaker on hollow stage floors, which can cause unwanted resonance. Use a sturdy table or microphone stand instead.

Thermal Considerations

The amplifier is convection cooled by a heatsink. Ensure at least six inches of free space behind the unit for efficient cooling. High ambient temperatures can cause overheating. In such cases, aiming a fan at the heatsink can help. If the amplifier overheats, a built-in thermal switch will activate, putting the unit into standby. It will resume normal operation once cooled.

Protect the unit from moisture, especially if used outdoors.

AC Power Considerations

Ensure the outlet can supply sufficient current. The SRM150 draws an average of 2 amps under maximum SPL conditions, and less than 1 amp under normal conditions. A robust AC power supply is recommended for optimal performance. If using lighting, power it from a separate circuit to minimize noise coupling into the audio signal. Connect all audio equipment to the same electrical circuit where possible to reduce ground loop hum. A maximum of five SRM150s can be connected per 15A service (120 VAC).

Power Sequencing: Turn SRM150s ON last and OFF first to prevent turn-on/off thumps.

Safety: It is advisable to use a 3-wire AC outlet tester to verify outlet wiring. Never remove the ground pin from the power cord; this is dangerous.

Care and Maintenance

To ensure years of reliable service:

• Avoid exposing the loudspeaker to moisture or extreme cold.
• If operating in cold environments, warm up the voice coil slowly with a low-level signal for about 15 minutes before high-power use.
• Clean the cabinet with a slightly damp cloth and mild soap solution only when the power is off. Avoid getting moisture into openings.

Connections

XLR Connectors

Inputs 1-2 use 3-pin male XLR connectors. Wiring is standard: Pin 1 (Shield), Pin 2 (Hot/+), Pin 3 (Cold/-).

1/4" TS Phone Plugs and Jacks

Used for unbalanced line-level signals and the high-impedance instrument input on Channel 1. Wiring: Sleeve (Shield), Tip (Hot/+).

1/4" TRS Phone Plugs and Jacks

Used for balanced signals and stereo headphones. Wiring: Sleeve (Shield), Tip (Left/Hot/+), Ring (Right/Cold/-).

RCA Plugs and Jacks

Used for stereo line-level inputs, common in home stereo and video equipment. They are unbalanced. Wiring: Sleeve (Shield), Tip (Hot/+).

Service Information

Before seeking service, consult the troubleshooting tips and the Mackie support website (www.mackie.com/support) for FAQs and documentation.

Troubleshooting

• No Power: Check AC outlet, power switch, and ensure the front panel blue LED is lit. Check the FUSE [9] if applicable.
• No Sound: Verify input gain [3] and MAIN LEVEL [6] controls are up. Ensure signal source is working and cables are secure. Check source output volume.
• Bad Sound: Check levels as per Quick Start guide. Ensure connectors are fully plugged in and secure. Clean connections periodically.
• Noise: Ensure all connections are good. Keep signal cables away from AC cables and power transformers. Check for light dimmers or SCR devices on the same circuit.
• Hum: Turn MAIN LEVEL down. If noise stops, it's from the source. If not, disconnect inputs one by one. Use balanced connections and ensure common ground for all equipment.

Safety Note: Never remove the ground pin from the power cord. This is dangerous.

Repair

For warranty service, refer to the warranty information. Non-warranty service is available at authorized service centers. Locate one via www.mackie.com/support. For assistance outside the U.S. or Canada, contact your local distributor. For technical support, call 1-800-898-3211 (US/Canada) during business hours.

SRM150 Specifications

Disclaimer: Mackie reserves the right to change specifications without notice. "Mackie" and the "Running Man" figure are registered trademarks of LOUD Technologies Inc. Other brand names are trademarks of their respective holders. ©2006-2010 LOUD Technologies Inc. All Rights Reserved.

SRM150 Block Diagram

The signal path begins with inputs (Channel 1 Mic/Line, Channel 2 Mic/Line, Channel 3 Line, Main In). These signals pass through individual Gain controls. Channel 1 also has a Hi-Z/Instrument option. The signals are then mixed and processed through a 3-Band EQ (Low 100Hz, Mid 2.5kHz, High 12kHz). The output of the EQ feeds into the Main Level control, followed by a Limiter. The Limiter output goes to the Power Amplifier, which drives the Loudspeaker. A THRU output is available after the input stage, before the EQ and Main Level controls, with a selectable Mic (-30dB) or Line level.

Mackie Limited Warranty

This Limited Product Warranty is provided by LOUD Technologies Inc. for products purchased in the United States or Canada through authorized resellers. It extends only to the original purchaser. For products purchased outside the U.S. or Canada, contact local distributors via www.mackie.com/warranty.

LOUD warrants the product to be free from defects in materials and workmanship under normal use during the Warranty Period. If a defect occurs, LOUD or its authorized representative will, at its option, repair or replace the product. Customers must notify LOUD of noncompliance within the Warranty Period. Retain the original dated sales receipt as proof of purchase.

Full terms and conditions, including warranty duration, are available at www.mackie.com/warranty. This warranty constitutes the entire agreement.

Contact Information

Mackie
16220 Wood-Red 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
Website: www.mackie.com
E-mail: sales@mackie.com