Atlantic Technology In-Wall Loudspeakers manual

Atlantic Technology Innovations for In-Wall Loudspeakers

Low-Resonance Tweeter (LRT™) and Directional Vector Control (DVC™)

It is obvious that people choose in-walls because they don’t want to see speaker boxes in their room. Furthermore, most people mount in-walls high off the floor— above the sight line—again, because people don’t want to see the speakers. The result of this is that much of the sound is focused above the listener's head and distorted in terms of the frequency response balance of the sound reaching the listener's ears.

Previous attempts to compensate for this non-optimal positioning have used some variant of the “pivoting tweeter” approach. But pivoting tweeters don’t work very well. Here’s why: two-way tweeters cross over too high in frequency—about 3,500-4,000 Hz—so it is the woofer, not the tweeter, that plays most of the midrange, and it’s the midrange that your ear uses to determine directionality.

Woofers beam badly in the upper midrange. If the woofer is above ear level, it’s going to beam the upper midrange like

a flashlight right over the listener’s head. The so-called “pivoting tweeter” is not much help, because it doesn’t play the midrange! And to make matters worse, when you pivot a tweeter, you introduce a ledge or shelf that diffracts the tweeter's output and smears the propagation of the treble frequencies.

It’s a messy, inelegant solution that probably does more harm than good.

So here’s what we did instead: We modified our tweeter so it can play lower frequencies; far

down into the midrange, about a full octave lower than a conventional tweeter to around 2,000 Hz. It’s a very highly- engineered tweeter system with a vented backplate, playing into its own sub- enclosure (complete with internal stuffing!), and special heat-sinking. We call it the Low-Resonance Tweeter (LRT™). Now the woofer doesn’t have to struggle to reach into the upper midrange, and we get a much smoother blend of radiation coverage angles as we transition from the woofer to the tweeter.

One of the characteristics of speaker performance is what engineers call “lobing.” A speaker’s output will lobe up or down, depending on things like crossover topology, driver positioning, etc. It can be very frustrating to develop, say, a new 35- inch tall floor-standing speaker and find

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