Mackie HR824

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Mackie HR824
Product Code: MACHR824

Obsolete

This product has been discontinued. Please contact our sales department for help in selecting a similar replacement.

Mackie HR824

Mackie HR824 Description:

The HR824 in action really is a revelation. The stereo sound field is wide, deep, and incredibly detailed. High frequencies and midrange are clean and articulated. Low frequencies are no more or less than what you recorded - you can actually hear the distinct tonal qualities (and harmonic quantities) of a particular bass instrument - instead of just a "generic" bass note. Most important, the sweet spot is a broad, 3-dimensional area that gives you room to move up, down, and across the console. In short, instead of having its own distinctive "sound," the HR824 sounds like the outputs of your mixer.

Part of the reason the HR824 has such a transparent stereo image and large sweet spot is the gently curving wave guide that encloses its alloy dome high frequency transducer. This waveguide greatly improves vertical and horizontal dispersion. In effect, it "nurtures" high frequencies created by the tweeter, guiding them as they expand out into the listening field. In comparison, a flush-mounted high frequency transducer on a passive monitor's front board has trouble coupling with the air mass of the room. It does OK directly on-axis, but can't disperse high frequencies to create a wide panoramic stereo image.

There's more. In a conventional monitor, treble (high frequency) and bass (low frequency) transducer dispersion patterns often differ significantly. Since midrange is spread between both high and low-frequency transducers, audible anomalies can occur at the crossover point. The HR824's wave guide lets us match the high frequency dispersion pattern to that of the bass transducer for a seamless midrange transition. It also recesses the high frequency transducer so that its active area is on the same axis with the woofer, providing acoustic alignment of high and low frequencies.

Shouldn't a soft, light fabric dome tweeter perform better than a metal dome? Our exotic FFT laser vibration analysis proves otherwise. Fabric tweeters undulate and ripple like a pond disturbed by a big splash. After performing about a zillion tests, we found a 1 in. alloy dome tweeter that has unusually smooth response along with excellent power handling. It creates true, pistonic motion up to 22kHz and couples perfectly with our logarithmic wave guide. You get pristine, uncolored treble that defines the finest details and upper harmonics of your recordings and mixdowns.

The visible portion of the HR824's low frequency transducer system is an 8.75-inch woofer with a mineral-filled cone and extra-long-throw voice coil with an exceptionally long peak-to-peak excursion. On the business end is a massive magnet structure far larger than what could be effectively used on a passive monitor. This mono bass transducer is directly coupled in a servo loop with a 150-watt FR Series amplifier. Amp circuitry constantly monitors the LF transducer's motional parameters and applies appropriate control and damping. This constant correction produces tight, articulate bass that accurately delineates individual bass notes and kick drum impacts - without the tubbiness, distortion, or overhang common among small monitors.

Like other near-field monitors, the HR824 augments bass transducer output by constructively adding the woofer's back wave 180 degrees out of phase. Unlike other monitors, the HR824 avoids the drawbacks of ducted ports or slots that can induce power compression and low frequency distortion or cause audible vent noise. Instead, the HR824's low frequency transducer is coupled to a composite honeycomb, mass-loaded 6x12-inch elliptical passive driver that "fires" out the rear of the enclosure. With a radiating area equivalent to a 12-inch woofer, it efficiently couples the servo-controlled woofer with your control room's air mass to deliver honest, verifiably-flat response to 42Hz with a 38Hz 3dB-down point.

Naturally, the HR824's enclosure is built like a proverbial tank with 0.75 and 1 in. high-resin wood composite. But our damping extends even farther inside the enclosure. A monitor's LF transducer also reproduces midrange up to 2kHz or so. In a box with minimal internal damping material, the LF transducer's midrange bounces off the rear wall of the enclosure and then exits back out the thin light cone and into your control room (left, top). It is distorted and out-of-phase, but distinct enough to create that "boxy midrange" that afflicts many small monitor speakers lined with only a thin layer of fiberglass.

The HR824's internal cavity is completely filled with high-density foam that absorbs internally-projected midrange before it can exit through the low frequency transducer cone (left,bottom). You can definitely hear the difference.

Mackie Designs is one of the few manufacturers of active speakers that also makes stand-alone power amplifiers. Bottom line: Mackie knows how to make good-sounding amps.

Using surface mount components (and a big toroid transformer), Mackie packed 2 genuine FR Series amplifiers into each HR824. The high frequency amplifier is rated at 100 watts with 150-watt peaks; the low frequency amp puts out 150 watts with 200-watt peaks. Both are high-current, low negative feedback designs that use our proprietary Fast Recovery circuitry to prevent latching when the amps are driven at their maximum.

On the HR824 front panel is a clipping LED and a signal present/power indicator that works with the HR824's Auto Turn-On feature. The power LED is subtle and dim so that it isn't distracting during long tracking and mixdown sessions.

The input panel on the back of the HR824 isn't a panel at all, but a vertical, downward-facing jack field. This lets you place monitors against a control room wall without the input jacks and power cord forcing the monitor away several inches.

The HR824 accepts virtually any line-level input from a mixing console. Overall speaker input gain is adjustable from (infinity) to 0dB attenuation with a small rotary control. Both balanced XLR and balanced/unbalanced TRS jacks are provided for inputs. The removable AC connection is a standard, easily-replaceable IEC power cord.

Besides the obvious off and on positions, the HR824's power switch has a third one. When set to Auto Turn-On, the monitor powers up its amplifiers immediately upon sensing an input signal. If no signal is present for several minutes, the HR824 goes into standby mode, ready for instant use.

Realistically, there are 3 ways you may end up arranging monitor speakers. When you place them out in the control room away from the walls, you're getting a "full space" sound from the speaker - that is, sound emanates naturally from all around the speaker. If you place a monitor against a wall you get "half space" sound; the wall boosts bass response. When monitors are placed in corners the result is "quarter space" sound, boosting bass response even further. None of these placements is bad. But each one has its own effect on your monitors' low frequency response. The HR824 provides compensation for half space and quarter space monitor placement with the acoustic space switch. In full space, the switch is set to position C. In half space, set the switch to position B, which lowers bass response by 3dB. In position A, for quarter space, bass response is lowered by 6dB. This allows you to keep as close to flat frequency response as possible.

Few if any "bookshelf" speakers can go as low as the HR824 (neither do many passive monitors, for that matter). To simulate playback on bass-challenged speakers, we added a Roll-Off switch to the HR824. When activated, it rolls off (reduces) low frequencies below 80Hz the way small home speakers do.

While control rooms are usually acoustically treated, you might also want to use your HR824s for mid-field playback in a more conventional room. For example, AV presentations in conference or boardrooms where the walls are likely to be "live" reflective wallboard or paneling. For these situations, Mackie has included a high frequency shelving control that reduces frequencies above 10kHz by 2dB. For unusually absorbent control rooms a high-frequency boost is provided that shelves frequencies above 10kHz.

It is suggested that you do some critical listening before you choose any near field monitor, active or passive. If you're listening to different monitor brands at different stores, always listen to the same, familiar selections - the best material is often a DAT mix that you've done on your own equipment. In this environment - up close and personal - Mackie firmly believes that you will immediately discern the HR824's superior accuracy, wider frequency response, and overall sonic clarity.

Mackie HR824 Specifications:

Enclosure Materials and Construction

3/4" (19mm) thick MDF construction with 1" (25.4mm) thick MDF front panel with radiused edges to minimize diffraction.

Proprietary exponential wave guide for controlled, wide dispersion from high-frequency driver.

Internal "H" brace adds to cabinet stiffness.

Open cell adiabatic "foam fill" acoustic damping material absorbs internal reflections, preventing delayed sound coloration.

Flush-mount connector system allows monitor to be placed against a wall without need for connector clearance.

Transducers

Low-frequency driver 8.75 in. (222mm) die-cast magnesium frame, mineral-filled polypropylene cone, oversized magnet structure, and over 16mm cone excursion.

High-frequency driver 1 in. (25.4mm) viscous edge-damped aluminum dome with ferrofluid-cooled voice coil.

Passive Radiator 6 x 12 in. (152 x 305mm) elliptical flat cone composed of aluminum honeycomb/phenolic with variable thickness filleted edge neoprene surround, mass-loaded, acoustic insulated.

Crossover Section

Crossover Type: Modified Linkwitz-Riley, 24 dB/octave @ 1800Hz

Sensitivity: 0 dBu nominal

Input Impedance: 20k ohm, balanced bridging

Compressor: Independent high and low frequency overload detection

Equalization

Acoustic Space Equalization (at 500Hz):

A = -4dB

B = -2dB

C = flat

Roll Off EQ: -3 dB @ 50Hz or 80Hz, 12dB/octave Multiple Feedback High Pass filter

High Freq. EQ: ± 2 dB @ 10kHz, shelving