HARMAN Intellivox Professional Loudspeakers User Guide

HARMAN Intellivox Professional Loudspeakers User Guide

INTRODUCTION

When designing an intelligible sound system for a less than ideal acoustic space, the biggest challenge is achieving a high direct to reverberant sound ratio. In other words, we need to maximize the sound arriving directly at the listener’s ear, while at the same time reducing the sound energy that hits and then bounces off hard, acoustically reflective surfaces such as walls, ceilings, windows and sometimes even floors.

The solution may seem simple but in practice it can be difficult to achieve with conventional loudspeakers. Even the most precise dispersion pattern will simply cover the area it is aimed at, regardless of whether that area is filled with a person, a soft furnishing, a glass panel or a marble floor. This is where the JBL Intellivox range can provide unique advantages.

JBL Intellivox products use our highly advanced Digital Directivity Synthesis (DDS) beam shaping algorithm. This allows custom shaping of the directivity pattern for the JBL Intellivox arrays to produce a beam which is tailored to precisely match the audience area within the space in which they are installed. As a result, the sound is aimed directly where it is needed – straight at the listener while avoiding the hard, reflective surfaces.

THE PROBLEM

When listening to a sound system within any space, you hear much more than just the sound system itself. What reaches your ears is in fact a combination of direct sound from the loudspeakers, reflected sound from the walls, floor and ceiling, and the ambient background noise of the space you are in. Worse still, all of those sources arrive at your ears at different times. It’s a lot for the listener to process; sometimes too much. Think of the last time you were in an airport or railway station – too much reflected sound and background noise can make an important announcement hard to discern while background music becomes a distant, muffled distraction. The same is true in any acoustically challenging space.

THE SOLUTION

The solution is to avoid those hard, reflective surfaces. To do so, we need to create a narrow beam of sound that can be aimed directly at the listener.

COVERAGE

If the solution sounds simple then the technology to achieve that solution is refreshingly clever. Thanks to the Digital Directivity Synthesis (DDS) beam shaping algorithm, JBL Intellivox products can provide even the most challenging of spaces with consistent, even and most importantly intelligible coverage.

Nor does the size of a space need to be a barrier to achieving clear sound and happy listeners. JBL Intellivox can precisely cover a large area from just one device. For example, a single JBL Intellivox DS500 can cover over 5,000m2 with an even Sound Pressure Level (SPL) over the audience or listener area.

INTELLIGIBILITY

From ornate houses of worship where sermons need to be heard and understood to transport hubs with vaulted ceilings and walls made of glass, intelligibility of speech and music is arguably the most important measure of success in any audio installation. It’s also one of the hardest to achieve.

Literally describing how easy it is to understand amplified speech or music in a given space, intelligibility relies upon two key factors:

• The Direct to Reverberant Ratio – The ratio of direct sound to reverberant sound;
• The Signal to Noise Ratio – The ratio of unwanted noise versus desired signal.

BEAM STEERING VERSUS DDS BEAM SHAPING… WHAT’S SO SPECIAL?

Beam steering is a well used phrase in modern commercial audio, but not all solutions are created equal.
That becomes clear when less nuanced technologies are compared to Digital Directivity Synthesis (DDS).

Over the following pages, we’ll look at how conventional beam steering interacts with complex audience planes, and why we experience unavoidable hot spots and reduced intelligibility caused by interference between the beams. The effect is a reduction in the overall performance of the array as the multiple beams segment and cause cancelations or interference lobes.

CONVENTIONAL BEAM STEERING…

As made clear in this diagram, conventional beam steering technologies demonstrate lobing and hot spots within the listening plane, resulting in uneven coverage and a reduction in intelligibility for the audience.

…VERSUS DDS BEAM SHAPING

Now, consider the same area but with JBL’s DDS Beam Shaping algorithm at work. We can see that the dispersion is mapped to match the room, ensuring uniform coverage and a consistent frequency response across the entire listening / audience area. This also delivers the benefit of improved intelligibility.

So we see that the distinct benefit of Digital Directivity Synthesis (DDS) beam shaping is that we can achieve the required coverage without having to rely on multiple beam sources, which can rapidly become destructive to the coverage and intelligibility in a space.

WHY A COLUMN’S ARRAY LENGTH IS IMPORTANT

An array is a collection of loudspeakers that is assembled to achieve a radiation pattern that cannot be achieved with a single driver. Sound waves sum in the target direction, while in other directions they cancel.
This cancellation is relative to the wavelength of a given frequency.

This means that for us to control a specific range of frequencies effectively, we must apply some rules as defined by the physics of sound:

• as wavelengths increase, the array length must also increase;
• as wavelengths decrease the distance between array components must also decrease;
• driver spacing at half a given wavelength affords the maximum cancellation off-axis.

When looking at a column loudspeaker you will notice that different column lengths and driver spacings are required to satisfy the above rules. For example, in order to control lower sound frequencies with longer wavelengths, you will require a longer array

DDS AND THE BENEFITS OF BEAM SHAPING

Standard beam steering is a useful tool. But when it comes to controlling audio coverage and intelligibility, Beam Shaping is the superior technology. Below we highlight how beam shaping offers more precise and even coverage.

Characteristics of Standard Beam Steering:

• Limited control over the array;
• Reduced aiming angle;
• Limited vertical opening angles;
• Multiple beams create more undesirable lobes and an increase in unwanted artifacts;
• Suitable only for far field coverage, as more beams are required to try to cover the areas closer to the array and therefore more lobing and uneven coverage occurs.

Characteristics of JBL Intellivox Digital Directivity Synthesis (DDS) Beam Shaping:

• Unrivalled beam control – hugely versatile coverage possibilities;
• Much improved nearfield coverage (compared to beam steering);
• Unrivalled frequency response – The DDS algorithm optimizes both frequency and SPL across listener planes;
• Single coherent beam, even when covering complex audience planes
• Independent control of near field vs. far field coverage
• Custom lobe matches the geometry of the space
• Ability to avoid reflective areas in the space, such as balcony fronts

THE JBL INTELLIVOX PRODUCT RANGE

Below is a handy guide to assist you in choosing the most suitable JBL Intellivox product for your project.

For applications that require high sound pressure levels or full range sound reinforcement, the JBL Intellivox HP High Power series can be used.

GREAT SOUND, SMART AESTHETICS

The JBL Intellivox range offers subtle aesthetics specifically designed to unobtrusively blend-in with the venue’s decor, putting architectural requirements first and ensuring that the listener is never distracted.
These elegant, slim columns are also designed to ensure ease of deployment, mounting, servicing and maintenance.

Some reasons to choose JBL Intellivox in your next project:

• Slim and unobtrusive design
• No need for mechanical aiming – units mount flush to the wall
• Units can be recessed into surfaces right up to the front grill and are therefore hidden
• Free color matching service available to visually blend into the building
• Can be integrated into buildings of all ages and styles

With an array of sizes and boundless application uses, JBL Intellivox offers pristine sound quality with ultimate control. This is why JBL Intellivox is heard but not often seen in houses of worship, shopping malls, transport hubs, outdoor public areas and event spaces across the world.

About HARMAN Professional Solutions

HARMAN Professional Solutions (harmanpro.com) is the world’s largest provider of professional audio, lighting, video and control
products. HARMAN’s best-in-class integrated solutions help customers to deliver the highest-quality results for concert tours, cinema,
retail, corporate, government, education, large venues, hospitality and more. With brands that include AKG®, AMX®, BSS Audio®, Crown International®, dbx Professional®, JBL Professional®, Lexicon Pro®, Martin®, and Soundcraft®, HARMAN Professional Solutions offers the most proven, innovative, and comprehensive solutions for the entertainment and enterprise markets. For more information, visit http://pro.harman.com/.

©2022 HARMAN. All rights reserved. Specifications subject to change.

References

• HARMAN Professional Solutions
• HARMAN Professional Solutions

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