oneZ realization

The oneZ speaker design came from an aesthetic of simplicity yet to execute it at the desired level of quality requires attending to a myriad of detail. Such are the delightful ironies of life that to build something simple can require very complex processes and procedures. Fortunately living in the 21st century has its perks. Thanks to computer aided manufacturing technology the details and precision required can be attended to in the design and manufacturing phases yielding a device elegantly simple in design yet sophisticated in execution.

In contrast with so many speakers which are a simple box+port tube oneZ has several key features hidden away in its walls and enclosure. Thus as the details of oneZ's realization are discussed we will begin with the parts and interior details then end with the exterior features.

parts tolerances and precision

The following diagram illustrates how the CNC cut birch ply parts are assembled to build a oneZ enclosure.

oneZ assembly side view

The wood components which make up the oneZ enclosure are cut using a CNC (Computerized Numerical Control) router assuring Cutting oneZ using CNC router

absolute repeatability. The tight tolerances thus attained enabled the extensive use of tongued-and-grooved joints. Combined with butt joints and modern adhesives the result is a locked together rigid structure. The precision of the router is such that the box can be trial assembled without glue and the tight precise fit will hold it together. Of greater import to the final result is the features this level of precision enables and resulting high quality level attained.

Too often products available to the DIY hi-fi market have been "dummied down" for home assembly and to meet cost targets. At Audio Crafters Guild we make no such concessions as we are dedicated to the proposition that our clients are craftsmen of the first order desiring the unique satisfaction of self built equipment that makes no concessions to mass produced gear. That is exactly why we are so excited that using CNC router technology has allowed the apparently conflicting goals of cost vs. performance vs. ease of assembly to be successfully reconciled.

A set of the oneZ plans in PDF format can be downloaded by clicking the link below. They may be of use during the following discussion.

Click to download oneZ plans in PDF format (125k).

interior details

Each oneZ speaker is composed of 19 components. These are:

1 ea. front 1 panel
1 ea. front 2 panel
1 ea. front 3 panel
1 ea. back panel
2 ea. side panels
1 ea. top panel
1 ea. bottom panel
2 ea. port manifold halves
4 ea. 3/8" x 5 3/4" hardwood dowels
1 pr. binding post terminals
1 ea. loudspeaker driver
18 in. twinlead wire
acoustic stuffing to taste
some dry fine sand.

oneZ front 3, port manifold, dowels, side, top & bottom assembly

The partly assembled view above shows how the tongue and groove joints interface the front, side, top and bottom panels. Also evident are the four dowels used to tie together and stiffen the side panels. When the second side panel is installed the precision cut grooves and holes exactly align locking together the panels into a solid stiff structure.

The joints between the top, bottom, and side panels are butt types. This allows the top and bottom to be tweaked up or down a few thousands of an inch to align perfectly with the side panels.

oneZ front 1, 2, & 3 driver holes

Loudspeaker drivers mounted in extra thick baffle assemblies can suffer from organ pipe resonance and flow restriction owing to the pipe created by a deep baffle hole around the driver. The photo above shows how oneZ avoids this by increasing the diameters of the driver hole in each of the three layers which make up the 1 3/4 inch thick front baffle assembly. Thanks to the CAD (Computer Aided Design) tools used the design addresses this issue while also assuring sufficient material is present to accept the driver mounting screws and allow the vibration trap to be implemented.

oneZ vibration trap

The precision of the CNC machined sand cavities which make up the vibration trap used in the front baffle subassembly allow it to wrap around the driver for maximum effect. For this picture front 1 and front 2 are assembled with the driver and sand installed (a condition never used in normal assembly sequences). When front 3 is glued on completing the tri-layer front baffle subassembly the sand is permanently sealed in resulting in a very stiff yet highly damped surface for the driver to reference.

oneZ manifold interior assembly

The design options enabled by CAD design plus CNC cutting is also evidenced in the enclosure's vent assembly. To avoid the possibility of port turbulence noise the area of the port is kept relatively large resulting in low air flow rates. For styling considerations the port area is divided into four square ports. With the precision of CAD and CNC the four holes are aligned exactly across parts front 1, front 2, and front 3. The final length required to tune the box is achieved by milling a manifold from two pieces of birch ply. As shown in the photo above when these manifold halves are glued together four square tunnels are created. One end of the tunnels exactly aligns with the holes in front 3 to which it is glued and the others are flared as a finial subtle performance tweak.

front 1 outside surface

front 1 inside surface milled to accept front 2

front 2 with driver, sand, & port cutouts

front 3 circumference milled to mate with
slots in sides, top, & bottom

back (on edge) circumference milled to mate with
slots in sides, top, & bottom

side (external & internal views) slots & holes milled
to mate with front 3, back, & dowels

top or bottom (internal view) slots milled to mate with
tabs in front 3, & back

manifold (one of two identical pieces)
two units are glued together forming quad ports

exterior details

oneZ presents a clean face to the world. In addition to the performance leap from the tri-layer damped front baffle the styling benefited as it allowed the outer layer to be carved from a single piece of birch ply or wood. No visible seams or fasteners mar the look. The four square vents add interest to the styling and their placement on the front allows near wall and shelf placement. This flexibility is especially useful when using oneZ in a multi-channel music or movie hi-fi system.

oneZ side view is devoid of seams across the sweeping side panels. Style details include the lightening holes at the rear and the floating front baffle. One inch of the tri-layer front baffle is exposed, undercutting of the second layer (stained purple in this custom finished example) yielding the rebate upon which the outer layer stands proud. Unseen is the front panel's inner layer locking the tri-layer baffle into the top, bottom, and sides grounded with tongued-and-grooved joints. oneZ floating front baffle

When finished in clear varnish and wood stains the finely layered structure of the birch ply is celebrated from multiple angles. From the side sixteen of the twenty four layers making up the front baffle are visible. Top, rear, and bottom views also reveal the layers of the side panels.

The exterior surfaces of oneZ present a blank canvas for finish options with the only limit being one's imagination. Fine sanding, varnishing, and polishing of the birch ply reveals a warm glowing light wood very much like the finest maples. The form and assembly sequence of oneZ greatly facilities the application of paints, laminates, or veneers.

The many rectilinear shapes which make up the oneZ enclosure lend themselves to dramatic color schemes. As this example shows a bold effect is achieved using the panel join lines as natural boundaries between metallic blue paint, purple stain, and natural birch finishes. The contrasts between the fine grain of birch veneer, the alternating dark and light layers of the ply ends, and the smooth metallic painted surfaces adds eye catching nuance to the overall effect.

assembly

oneZ is like a high-end custom motorcycle in that it is available in kit, standard factory assembled, and custom bespoke configurations. With the CNC cutting technology employed assuring ease of assembly both novice and advanced kit builders are freed to concentrate on their craftsmanship, finish, and detailing.

The kit builders assembly sequence is quite simple:

Glue two port manifold halves together and then to the back of front 3.
Glue front 3 and back to side 1 panel using their slots and tabs.
Glue top and bottom to front 3 and back using slots and tabs and butt joints to side.
Glue four stiffening dowels to holes in side 1, temporarily install side 2 without glue to align dowels as glue dries.
Glue front 2 into recess on back of front 1. Stop and allow all glue to set.
Depending on finish desired this may be the point to sand, stain, and varnish.
Remove side 2 and install binding post terminals and speaker wire.
Glue side 2 onto rest of enclosure.
Lay front 1 & front 2 subassembly face down on level surface. Fill vibration trap cutouts with clean dry sand.
Glue front 1 & front 2 subassembly to rest of enclosure using recess created by sides, top, and bottom extending past front 3 outer surface.
Connect wires to driver and install driver into enclosure.
Enjoy.

When a factory built oneZ is selected the assembly sequence is even simpler:

Unpack speakers and set in place.
Connect wires from amp to oneZ.
Enjoy.

The concepts which defined the architecture that led to the realization of the oneZ speaker have yielded a device combining functional versatility with musical purity. Reproducing music with the verve and transparency unique to a direct coupled point source the result far exceeded expectations for such a diminutive transducer. We invite you to consider the myriad ways in which oneZ can enhance your listening experiences.