Mackie SRM450 Powered Speaker Package

MACKIE SRM-450 Details ^top

WE WORKED TWO YEARS TO GET IT RIGHT
It doesn't matter if you're a DJ, church, or Iron Maiden tribute band, you need loudspeakers that won't crap out in the middle of a show, or distort when you turn them up past 3.

That's why we designed the SRM450—the first and only portable active 2-way loudspeaker with onboard bi-amplification, active crossovers, time-correction and renowned Mackie sound quality. Thanks to countless hours of R&D—and one very-hard-to-please Greg Mackie—the SRM450 delivers real, accurate bass down to 55Hz; midrange that's free from ear-fatiguing harshness; and detailed treble out to 20kHz. Better still, the SRM450 offers astonishingly wide dispersion that lets your whole audience hear clearly, whether they're in the front, back, or way out on the sides of the room. Above all, the SRM450s crank! Without a hint of distortion, they effortlessly achieve sound pressure levels beyond the legions of look-alike portable loudspeakers on the the market today.

ULTRA-WIDE DISPERSION
Ever been to a show where the music sounds great in front, but craps out once you get to the back or sides of the room? We have, and that's why we gave the SRM450 a multi-cell horn throat aperture. Sure, it's hard to say, but what it does is allow for much wider and more even dispersion of high and mid frequencies — so the wallflowers get the same great listening experience as those up front.

Part of the inspiration for the SRM450's horn design came from listening to big high-output studio monitors. They had smoother on-axis response and lower distortion because they used an exponential horn design that kept the air impedance constant and the sound smooth as silk. Today's widely used "constant directivity" horns control dispersion relatively well, but their straight walls generate reflections that cause distortion.

However, on big studio monitors, the off-axis pattern control wasn't great.

Pattern control can be loosely defined as "similar off-axis response at a wide range of frequencies." Lots of speakers claim "90° horizontal dispersion." But when you examine their polar patterns closely, you discover that they don't achieve 90° dispersion at all frequencies (drawing at left). In real world, as opposed to the laboratory, when you walk into a live venue, you spend most of your time standing off-axis to the speaker system. When a speaker has uneven dispersion (poor pattern control) at higher frequencies, full-range sound projects straight out like a beam. That's great for the listeners right in front of the speaker, but off-axis listeners get muddy, dull, uneven sound.

Poor pattern control (grey areas) is the result of uneven dispersion at various frequencies. The speaker may do ok at 1kHz but "beam" increasingly narrow patterns at higher frequencies.

So here was the problem: how to take advantage of an exponential horn's smooth response, but solve the problem of high frequency beaming.

The solution was a combination multi-cell aperture throat and exponential horn geometry to obtain the desired dispersion pattern and lower distortion.

Thanks to the efforts of a pair of the world's best acoustic scientists, we were able to retain the finned horn's dispersion advantages while reducing distortion problems. Our researchers provided the mathematical calculations and modeling that led us to create a two-piece vaned horn throat aperture and a separate exponential/conical horn. By placing the phase plug of the driver right next to the fins, we minimized reflection problems.

The design also resulted in a very large horn mouth that provides excellent power response at the crossover point. Stand up to 45 degrees off-axis and you still get wonderful, full-range performance.

TIMING IS EVERYTHING
In most loudspeakers, the compression driver that reproduces mid and high-frequencies is located deep inside the enclosure, while the low-frequency driver is much closer to the front of the enclosure. With this setup, bass arrives at listeners' ears sooner than treble, muddying the sound. We remedied these unfortunate laws of physics with high-zoot electronics which allow precise alignment among the system components with zero signal degradationElectronic Time Correction for Simultaneous Sound Arrival and Correct Phasing.

To understand why onboard Time Correction is important, one need only consider the basic physics involved in typical 2-way loudspeakers. In this type of loudspeaker, the compression driver that actually reproduces mid- and high-frequencies is located deep inside the speaker enclosure. Once sound is produced, it must travel from the compression driver through the horn to the listener. On the other hand, the LF driver (i.e. the "woofer") is much closer to the front of the speaker.

The result, put simply, is that bass arrives at listeners' ears sooner than treble. To solve this, you need a way of correctly timing the arrival of electrical impulses at each kind of transducer. In other words, the compression driver needs a "head start" over the LF transducer so the differences in sound generation speed can be accounted for, and both sound signals arrive at the listeners' ears simultaneously.

Some passive speaker systems use a coil (and/or capacitor) in an attempt to delay the signal. But this can degrade the signal.

In contrast, sophisticated electronics inside the SRM450 allow precise alignment among the system components without any audio signal degradation. This is especially important as distance from the loudspeaker decreases; the closer you get to the loudspeaker, the greater effect Time Correction has on the quality of sound, and your fans deserve the best, right?

In the SRM450, additional time correction accuracy is achieved via separate Linkwitz-Reilly 24dB-per-octave crossover circuits for the woofer and HF driver. This same electronic system also helps combat phasing problems.

So what's in it for you? Glad you asked. When the signal you hear is completely in phase, you get imaging, depth of field and real definition. When it's not in phase, you get inconsistent sound with lots of muddy artifacts that change the listening experience as you walk around the room.

So the result of the SRM450s onboard electronic Time Correction is audibly clearer sound that stays consistent over more of your room.

BETTER THAN YOUR AVERAGE BOX
Anyone with a factory can build a box and stick some speakers in it (and that's just what many do). But low-frequency transducers in square boxes can create resonances that reflect off the rear wall and pass through the woofer cone out of phase, and ready to mess up your sound. The SRM450 enclosure is an asymmetrical monocoque design with no parallel surfaces, causing mid and high frequency resonances to be reflected at angles into internal damping materials, instead of interfering with the woofer doing its thing. Greg Mackie has always been a stickler for ease of use and ergonomics. The challenge was designing a molded enclosure that met his criteria for convenience and strength. The resulting extremely complex asymmetrical trapezoidal cabinet design totally nuked our development budget, drove the mold-makers crazy, and resulted in a $700,000 32-ton mold! But it was worth all the effort.

An asymmetrical, rounded enclosure has several advantages. First it results in the stiffest, strongest, most durable cabinet in its class. Second, it can lie on its side in the perfect stage monitor position. Finally, the SRM450's acoustic signature also benefits because it suffer less from typical internal standing waves created by symmetrical designs.

The SRM450 enclosure has three handles; two located on the sides and one on top. The side handles are center weighted — the heat sink, components, toroidial power supply, and everything that impacts weight distribution of the enclosure is therefore balanced in relation to the handles. Pick up a competitor's box and you'll appreciate this attention to detail.

The SRM450 also has 10 integrated fly points that make it easy to hang or fly in any position.

DUAL FR SERIES AMPLIFIERS
Let's face it, 99 percent of the time compact PA speakers are cranked to the max. That's why the SRM450's beefy internal 400-watt amplifier section features dual FR series amps — one for each driver — both designed for extreme output. The amp section is built around a huge toroidial transformer, massive storage capacitors, and state-of-the-art output transistors, all adding up to superior sound, night after nightOnboard FR Series Power Amplification and Electronics

Thanks to our years of power amplifier development, Mackie knows amplifier technology inside and out. The 300- and 100-watt FR Series amplifiers inside the SRM450 are clean-sounding, ultra-reliable, and — most importantly — designed specifically for the drivers in the SRM450 loudspeaker. This last point is crucial because the amplification requirements of a low-frequency driver are enormously different from that of a mid-/high-frequency compression driver.

Low Frequency drivers (regular folk know them as "woofers") are relatively inefficient due in part to the larger size of their moving parts, voice coil, cone, spider, and suspension. So, to properly control an LF driver and move a lot of air, you need an amp that delivers loads of voltage to handle the mass of the woofer cone and keep it moving in a straight, linear, controlled manner.

Compression drivers, on the other hand, are very efficient and need a relatively low amount of voltage compared to their low frequency brethren to achieve high SPL levels. However, the very nature of horn loading requires more equalization to smooth out the response. If the amplifier is too puny, this additional equalization can put the system dangerously close to clipping. So it's far better to have more amplifier headroom than needed to handle transients (i.e. loud volume peaks like big snare or kick hits, slap bass, or singers having a Dio moment).

With the SRM450, we spent countless hours developing and tuning the internal power amps for optimum performance within the entire loudspeaker system. So with Mackie Active loudspeakers, you don't have to worry about amplification. You just plug-and-play.

SERVO FEEDBACK CONTROLLED LF TRANSDUCER FOR STUNNING BASS
Based on Mackie's award-winning HR824 studio monitor technology, the servo feedback damping electronic circuit within the SRM450 provides amazing results. The circuit "locks" the woofer in place with the positive and negative outputs of the amplifier in a way that no external amp and passive woofer can ever achieve. This creates a solid direct-coupling that delivers extremely deep bass from a small cabinet.

SUPERB FLOOR MONITOR
When the first warranty cards came back, we noticed that a lot of folks were raving about what a great floor monitor the SRM450 made. Okay, it's super accurate. And it's designed to be tilted. But there had to be more reasons than that.PATTERN CONTROL: WHY THE SRM450 MAKES SUCH A SUPERB FLOOR MONITOR

A good floor monitor plays loudly without generating feedback through vocal microphones. A poor floor monitor, on the other hand, will generate feedback just about the time you turn it up to a useable level. Floor monitor feedback is often caused by uneven frequency response and dispersion; some frequencies arrive at the microphone much louder than others. These "spikes" are what trigger feedback as the floor monitor volume is increased. The SRM450 has incredibly smooth, spike-free response and dispersion over a wide range of treble frequencies. So you can increase its volume without boosting those nasty, feedback-inducing spikes. No passive speaker or specialized floor wedge in this class of speaker can even come close.

• 2-way bi-amplified, optimized active system
• Built-in precision 24dB/oct. Linkwitz-Riley electronic crossover
• High-output precision titanium compression driver
• 300mm long-throw low frequency transducer
• Studio-quality maximum dispersion horn design
• High SPL Output/Low Distortion
• Electronic Time Correction, Phase Alignment, & Equalization
• Servo Feedback controlled woofer
• Tough, impact-resistant, lightweight polypropylene enclosure
• Gig-bag available