INTRODUCTION

Thank you for choosing Mackie Designs’ HR824 Studio Monitors. We realize that monitors are a critically important tool whether your application is studio recording, audio/video post production, hi-fi, or home theater. Knowing this, Greg Mackie had a simple mandate: Design a reference monitor with a degree of accuracy and versatility unmatched by any other in its size and price category — or any size and price category for that matter. The mandate was simple, but accomplishing it was another story!

Investments in Excellence...

To accomplish the task at hand, Greg and the New Product Development team realized that a commitment was required in terms of new resources and new equipment. So we recruited some of the best speaker and acoustic engineers in the industry to assist in the design of the HR824. And we invested in some advanced (and need we say expensive) measurement and analysis tools for the design team to use.

The result? The HR824 Studio Monitors are extremely accurate and versatile, loaded with unique controls that allow you to fine-tune the sound to match your individual environment precisely. You’re gonna love these!

What are they? The Advantages...

The HR824 Studio Monitors are high-resolution, two-way, bi-amplified, active monitors employing a 6th-order Butterworth system with a built-in rear-firing mass-loaded passive radiator. Whew! There are many benefits to integrating an active crossover, power amplifiers, and drivers into a single cabinet, and we’ve taken full advantage of these benefits in the design of the HR824.

•The crossover point is designed so that the high and low frequency drivers are fed only the frequencies they are best able to reproduce.

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

•In addition, the amplifiers’ gain and fre- quency responses are individually hand-trimmed to compensate for typical manufacturing tolerances between the

drivers and produce a smooth frequency response from 39Hz to 20kHz (± 1.5 dB).

•The connecting wire between the amplifier outputs and the drivers are kept to an absolute minimum, so the damping factor of the amplifier isn’t compromised by the resistance of long speaker cables.

•The acoustic sum of the outputs from the two drivers are optimized electronically, as well as physically, so the amplitude response is unity and the phase difference is minimal.

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 monitors feature an 8.75-inch die-cast magnesium frame woofer and a 1-inch viscous edge-damped aluminum-alloy dome tweeter on the front, and a 6-inch x 12-inch elliptical flat piston passive radiator in the back.

The high-frequency driver is mounted on a massive, acoustically non-resonant die-cast zinc exponential waveguide which results in wide, controlled dispersion of high-frequency sounds. The unique passive radiator design provides a smooth response down to 39Hz — an astounding accomplishment for a cabinet of this size! And since the radiator is producing most of the sound at the lowest frequencies, there is very little distortion from the woofer because its cone movement is minimal at those frequencies.

The Cabinet...

The cabinet is made of high-density MDF wood. An internal “H” brace further increases the strength and rigidity (stiffness) of the box. An open-cell adiabatic foam material fills the inside of the box to absorb internal reflections and dampen standing waves.

FR Series Power Amplifiers...

What better way to power the loudspeakers

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

The low-frequency amplifier produces up to 150 watts continuous (350 watts peak) before clipping, while the high-frequency amplifier produces up to 100 watts continuous (210 watts peak).

Tweeter

"H" Brace

Passive Radiator

 

 

Power Amplifier/

Woofer

Crossover Assembly

 

Figure 1. HR824 Cutaway side view

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