SRM V-Class: Making Speakers More Intelligent with Advanced Impulse DSP

One of the biggest challenges for every musician is getting the music they’ve labored over in the studio to sound as good in a live setting. Most modern PA systems are designed to deliver a much different kind of sonic performance than the monitors you listen to in your studio setup, or the consumer technology most of us might be listening to at home.

 

Mackie’s SRM Series was designed with a simple principle: create a loudspeaker that sounds like a studio monitor. With our fully re-imagined SRM V-Class, we are furthering that goal with new technologies that will preserve the integrity of your music, no matter where it is heard. Mainly, our goal is to deliver the same balanced, uncolored sonic footprint you expect in a studio monitor, but in a PA speaker. We pulled it off through a lot of different methods at once, but one of the most advanced is our proprietary Advanced Impulse DSP.

Advanced Impulse DSP corrects the inaccuracies you typically get from lesser PA systems, using a precise method that leaves the rest of the music untouched. The result is a stunning level of accuracy and authenticity, just like the studio. 

 

Here’s how it works.
 

The first thing to understand is that a loudspeaker system is a combination of components, all designed to work together. And component selection is important. Each component has its own inherent sonic anomalies, meaning it can resonate at some frequencies more than others, causing a “boost” at those frequencies. With all the components resonating differently, these “boosted” frequency bands can overlap, impacting overall performance in a way that makes your music sound different. In much the same way adding or subtracting EQ on two different tracks can result in certain frequencies being emphasized or de-emphasized in the overall song, the same can happen when the resonances of different components interact. Phase interaction and magnitude response can and do influence a system’s performance.

 

For example, think of how transducers operate—like a woofer, for instance. You have a cone that’s moving back and forth, generating waveforms. If you have two different transducers generating the same frequency, but they’re both moving in opposite directions, they end up cancelling each other out. The result is a dramatically reduced output, and diminished performance. You try to crank the volume, but if you’re cranking the volume on both at the same time, the problem only gets worse. And the larger the system, the more apparent this will be.

Traditionally, most manufacturers compensate for these anomalies by using IIR (Infinite Impulse Response) filters—basically a parametric EQ that enables system designers to smooth out the “notches” where frequencies overlap or leave holes. The problem with EQ is that it introduces its own phase response issues. IIR is a blunt instrument, improving the sound but still leaving the music significantly different than it sounded in the studio. 

A more recent breakthrough has been the use of FIR filters—Finite Impulse Response. Because FIR filters have a finite amount of time before they return to zero, their impact on system performance is greatly reduced. If IIR filtering is a blunt hammer, FIR filtering is more like a needle. A FIR filter can deliver far more granular and detailed control of phase and magnitude response—a powerful tool for loudspeaker system designers, especially when they are looking to alter the source material as little as possible.

 

By using advanced  FIR filters, Advanced Impulse DSP allows SRM V-Class to control phase and magnitude issues with infinitely greater accuracy than IIR filters ever could achieve. 

Of course, all that control would be pointless if we didn’t know exactly what issues we are correcting. The more precise the data we have on a system’s performance, the more accurately we can program the FIR filters to control that performance. 

 

Most loudspeaker designers rely on axial measurement—a single path straight down the middle of a speaker’s coverage area. The problem is, audiences don’t stand in a perfectly straight line in front of the speaker. They move throughout the “dispersion zone” (the space that a speaker is meant to cover). Because of the way sound waves reverberate, frequency and phase issues can happen in some areas of that zone and not others. The result is that an audience member may hear good sound when standing directly in front of the speaker, but when they move to another area—say, to get a drink at the bar—all of a sudden, the music sounds muffled and strange. You want the entire audience to have the best experience possible, not just the ones who happen to be standing in the right spot.

 

There must be a better way to measure the accuracy of a speaker, one that picks up anomalies throughout the space—and with SRM V-Class, we found one.

Mackie’s Advanced Impulse DSP utilizes the most accurate, multipoint measurement tools available, delivering us highly detailed information on speaker response, output and performance at any point in space. It’s that information we use to program the SRM V-Class algorithms. The result is a system that is inherently flatter and far more accurate, without introducing any coloration of its own, no matter where you are in the dispersion zone (90 degrees horizontally and 60 degrees vertically. What that means for you is a more consistent audio experience for the entire audience. Your music sounds as good live as it does in the studio, to everyone who hears it. 
 

Advanced Impulse DSP combines the benefits of FIR filtering with our precision measurements of the entire dispersion zone, creating a super high-tech solution to age-old problems. You can get even more detail in this technical deep dive video featuring acoustic engineer Ethan Bannister. 

 

But SRM V-Class is about being “best in class” in every way, not just one way. These speakers start from the beginning by selecting the absolute best components, minimizing the unflattering resonances from the beginning. There are also other proprietary technologies including the Sym-X horn and SRM Mix Control. Read more about more ways SRM V-Class sets a new industry standard with our blog on the subject—and keep demanding the best!