Lend Me Your Ears

Exposure to extremely high noise levels may cause permanent hearing loss. Individuals vary considerably in susceptibility to noise-induced hear-

ing loss, but nearly everyone will lose some hearing if exposed to sufficiently

intense noise for a period of time. The U.S. Government’s Occupational Safety and Health Administration (OSHA) has specified the permissible noise level exposures shown in this chart.

According to OSHA, any exposure in excess of these permissible limits could result in some hearing loss. To ensure against potentially dangerous exposure to high sound-pressure levels, it is recommended that all persons exposed to equipment capable of producing these levels use hearing protectors while this unit is in operation. Ear plugs or protectors in the ear canals or over the ears must be worn when operating this amplification system in order to prevent a permanent hearing loss if exposure is in excess of the limits set forth here.

Duration Per Day
Sound Level dBA,
Typical

In Hours

Slow Response
Example

8

90

Duo in small club

6

92

 

4

95

Subway Train

3

97

 

2

100

Very loud classical music

1.5

102

 

1

105

Patrice screaming at Ron about deadlines

0.5

110

 

0.25 or less

115

Loudest parts at a rock concert
The HRS150can produce amaximum SPL of122 dB @ 1 m

INTRODUCTION

Thank you for choosing Mackie Designs’ HRS150 Powered Subwoofer. We realize that monitors are a critically important tool whether your application is studio recording, audio/video post production, hi-fi, or home theater, and the use of a subwoofer not only improves low-frequency accuracy for stereo monitoring and playback, but is absolutely necessary for surround sound applications.

The HRS150 complements our line of studio reference monitors and, like our HR824 and HR624, meets all THX™ requirements for mixing and monitoring multi-channel programs.

In order to achieve a seamless integration between the subwoofer and the main speakers in the system, speaker placement is very important. The characteristics of the room and the location of the speakers, including the subwoofer, relative to the walls and your listening position can have a drastic effect on the accuracy of the sound. We’ve provided a section on positioning the subwoofers, offering tips on how to find the best placement for your particular application.

What is it? The Advantages...

The HRS150 is a high-resolution powered subwoofer employing an internal variable 4th-order Linkwitz-Riley crossover system with a down-firing RCF Precision 15“ woofer and two side-firing mass- loaded passive radiators. Whew! There are many benefits to integrating an active crossover, power amplifier, and drivers into a single cabinet, and we’ve taken full advantage of these benefits in the design of the HRS150.

•The crossover point is variable so that the high- pass output can be programmed to match the frequencies the main speakers are best able to reproduce.

Part No. 0006805 Rev. B 5/03

©2003 Mackie Designs Inc. All Rights Reserved.

•The amplifier is designed to provide maximum acoustic output from the speaker, yet minimize the danger of speaker damage due to overdriving.

•The connecting wire between the amplifier output and the low-frequency driver is kept to an absolute minimum, so the damping factor of the amplifier isn’t compromised by the resistance of long speaker cables.

In short, all the complex interconnected components in the system are designed to work in harmony with each other to produce the best possible sound.

The Transducers...

The subwoofer features a bottom-firing 15-inch die-cast frame woofer and a 15-inch passive radiator in the front.

The unique passive radiator design provides a smooth response down to 19 Hz—an astounding accomplishment for a cabinet of this size! And since the radiator is complementing and adding to the output at the lowest frequencies, there is very little distortion generated from the woofer because its cone movement stays well within its maximum excursion.

The Cabinet...

The cabinet is made of black oak veneered MDF wood. Extensive internal bracing further increases the strength and rigidity (stiffness) of the box.

The box is packed with an adiabatic polyester-fill material to absorb internal reflections and dampen standing waves.

FR Series Power Amplifiers...
What better way to power the subwoofer than

with our acclaimed FR Series “Fast Recovery” power amplifiers. Our Fast Recovery design uses low negative feedback, yet allows the amplifier to maintain low distortion and stability even when driven into clipping.

The low-frequency amplifier produces up to 950 watts continuous (1050 watts peak) before clipping.

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