For a number of years the concept of a double-top soundboard has been gaining appreciation and acceptance in the steel-string world. The Ryan Acoustic Parallel Plate (APP) is my take on this concept. But being the maverick I am, I wanted to go a new direction with it. I decided that I wanted to retain a very wooden and organic sound so I have chosen to make my APP entirely from wood (my current version is Sitka spruce and will likely remain so).

The engineering philosophy behind a Double Top leverages the incredible stiffness of an I-beam design. I will spare you the involved mechanics of the thing, but just know that the two plates that comprise the APP (just as in a Double Top) are separated by an extremely lightweight core with the two “skins”, one on each face, bonded to this core. One of the “skins” is, of course, the soundboard. The resulting plate assembly is phenomenally stiff and light. This concept was common in the Northrop Aeroscience Laboratory where I worked in the late 80s and mid 90s as a research assistant, testing fighter jet designs in our transonic wind tunnel.

In the popular Double Tops now being made, the core is Nomex, a phenolic honeycomb material. In the common method in vogue right now, the entire soundboard is this bonded assembly. In my Acoustic Plate, the honeycomb is a section of quarter-sawn spruce which I laser-cut here in my shop. My thinking was to instead leverage the marvel of this design only in the area immediately behind the bridge where the lion’s share of the tone is generated and where most of the torque and stress of the bridge is concentrated. The goal is to reduce the mass of the soundboard in the area I call the Acoustic Crescent--that sweeping arc just behind the bridge and which extends to each edge of the soundboard. This has allowed me to altogether eliminate every single soundboard brace below my EO X-brace (I have kept all the bracing above the X-brace unchanged).

Nearly light as air, this new plate bracing the soundboard is nonetheless stiffer than any traditional bracing scheme. I believe it also affords the complementary benefit of quickly transmitting acoustic energy to a wider area of the Acoustic Crescent. The bridge pins extend through the bridge, soundboard and APP to anchor the string ball ends against a laser cut ebony plate designed to be as small as possible. A pinless bridge is also very viable with this system.

The net acoustic result of this new Acoustic Parallel Plate is to create a light, stiff and consistent soundboard that is very responsive to the lightest touch on the strings. But it is robust enough to welcome an aggressive attack to the strings as well. And to top things off, I find a lovely shimmer and sparkle at the upper registers and partials of the notes, especially the trebles. (For more information about harmonics, technically known as “partials”, please see my article on Tempered Tuning)

The Ryan Acoustic Parallel Plate will be standard on my new Grand Concert, the Paradiso. My traditional bracing is available upon request for this model.

This APP system will also available on all my other models as well.

On another note, I would like to thank my good friend Peter Marreiros (Cornerstone Guitars) for his encouragement in pursuing a double top. Peter’s Double Top version is very cool and unique and also completely wood. For information about his design, you may find something on his website, www.cornerstoneguitar.com. Also, my good friend and great builder Charles Fox is a leading proponent of the Nomex-style Double Top. Charles’ site is here.

I have heard that the Double Top concept was first introduced to the guitar world by some German luthiers. I would like to give them due credit but I don’t know who they are. If any of you have reliable information about their identity, please let me know so that I can post it here.