Bob’s Amazing Line Source breaks the mold of any previous design.

A true line source speaker is simply a speaker so tall and acoustically long that we, the listener, hear a speaker that goes all the way to infinity. Up to infinity and down to infinity, resulting in what a scientist would call a "perfect wave launch."


The wave from such a speaker behaves as if it emanates from a gossamer-thin filament running from below the center of the earth to beyond the moon: A pure, beautiful, cylindrical sound wave. When we listen to such a wave, we find that we can hear musical nuances that we often cannot hear at all using normal speakers.

Line Source

Crossover Module

2 x 10-inch

Sunfire SubRosa™ subwoofer (shown below with grille on.)  Includes separate 2700-watt amplifier/processor


An illuminating analogy.

An Illuminating Analogy


Imagine a thin, eight-foot-tall pole extending from floor to ceiling. On the pole are mounted thirteen lighted birthday candles, each a light source. Additionally, imagine the floor and ceiling of our room to be perfectly polished mirrors.

When we look down at the bottom of our speaker, we will see lit candles reflected in the mirror continuing all the way down to minus infinity — far below the actual floor.


If we look up towards the top of our speaker, we will see reflections of candles that go up to plus infinity beyond the farthest star in our galaxy. The top and bottom of the room and its physical limitations seem to vanish, leaving only the splendor of the concert hall in the listening room.


All these above-ceiling and below-floor reflections PLUS the actual thirteen candles are all real light sources to our eyes. We can read a book by their light. The candles in the mirrors make as much light as the actual candles on that pole. Absolutely non-intuitive!

The result is an infinitely long, gossamer-thin ribbon of sound…because the same holds true for speakers, candles and ribbons alike: the virtual candles/ribbon drivers make just as much light/sound as the “real” candles/drivers in the room.

Tower of Song.

Each Amazing Line Source is an eight-foot tall, resonance-free alloy extrusion with thirteen vertical and one horizontal spatial ribbon — approximately 280 times more area than a dome tweeter — a classic example of the difference between a point source and a line source.

Bob respected the capabilities of ribbons, but struggled with their on-going problems of buzzing, lack of sensitivity and other negative factors.


Because Bob couldn’t find any existing ribbon transducer designs that fit his demanding requirements, he went directly to a factory to commission the ribbons now used in the Amazing Line Source.

Their wave guides are made of duraluminum, an extremely hard alloy of magnesium and aluminum; the actual ribbon membrane is made of Kapton and aluminum.  Internal coil windings are extremely dense to increase sensitivity.


Low mid and high bass is handled by eighteen side-firing transducers, which provide 830 cubic inches of displacement. Their gentle crossover frequency “overlaps” the ribbons up to approximately 9 kHz. This extreme overlap, together with phase delay in the crossover Control Module yields a soundstage with remarkable width and depth.

The Crossover Module connects between your power amplifier(s) and each Amazing Loudspeaker, providing controls for Bass Damping, and adjustment of Upper Midrange and High Frequencies.

Bass below 90 Hz is handled by an included SunFire XTEQ12 subwoofer.  With 12-inch, high-excursion Neodymium woofer and 12" side-fireing passive radiator, this high back EMF design does the work of several conventional subs, easily pressurizing a 3000 cubic foot room with even bass coverage throughout. High-current power to the drivers is provided by an internal 3000 WRMS power amp.

This is science, not magic.

For a detailed explanation of the principles behind the Amazing Line Source, click the Deep Reading 4 link.  You’ll further understand why Bob’s speaker design presents such a huge and majestic soundstage, capturing captures the complete sense of acoustic space that helps make music come to life in our listening rooms. But reading it is not necessary if you can hear these speakers in action.


You will hear sound images inside a larger acoustic space that seem so real it is downright spooky. The soundstage extends far behind the speakers, wider than the speakers, higher than the speakers, possessing a majesty that you will find difficult to believe. But not so difficult that you WON’T believe it.

Bob’s goal is that every time you listen, you will find yourself asking, “How do they do that?” A solo female singer will appear center stage, up and back slightly, perfectly focused, singing her heart out as if she were in our room, all the while being inside that larger acoustic bubble; Beethoven's Ninth symphony will bring tears to your eyes.

Perhaps even more amazingly, the Amazing Line Source will bring its imaging, soundstage, and spatial characteristics into your listening room with as little as 60 watts of tube power or 120 watts of solid-state)!  You won’t get wallpaper-peeling sound levels, but for chamber music, acoustic guitar or other slightly more delicate program sources, you will be enchanted. Naturally, the true majesty and impact of these speakers comes when you apply 350 watts of tube power (such as our Crimson and Raven amps) …or just go nuclear and run them with a pair of Bob’s mighty Silver Seven 900s for the ultimate live performance experience.