Ready-to-build plan

Dayton Audio UMII15-22 Ultimax II 15" DVC Subwoofer 2 Ohms Per Coil Sealed Subwoofer Enclosure Plan with DXF Cut Files + 3D Model

Name: Dayton Audio UMII15-22 Ultimax II 15" DVC Subwoofer 2 Ohms Per Coil Sealed Subwoofer Enclosure Plan with DXF Cut Files + 3D Model
Brand: Dayton Audio
SKU: dayton-audio-umii15-22-ultimax-ii-15-dvc-subwoofer-2-ohms-per-coil-sealed
Price: 19.99 USD
Availability: InStock

Sealed enclosure plan for the Dayton Audio UMII15-22 Ultimax II 15" DVC Subwoofer 2 Ohms Per Coil: 85 L net, finished box 449 × 449 × 615 mm (W × H × D), Fc 43 Hz, F3 33 Hz. Whole-millimetre DXF cut files + STEP/STL 3D + cut list + predicted response.

Get the plans on Gumroad · $19.99 Instant download · Secure checkout on Gumroad

Dayton Audio UMII15-22 Ultimax II 15" DVC Subwoofer 2 Ohms Per Coil Sealed Subwoofer Enclosure Plan with DXF Cut Files + 3D Model

What it will sound like

No guesswork on the sound. This box is engineered to a defined sealed alignment (Qtc 1.02), and the chart below is its predicted frequency response: a warm roll-off with a gentle low-end lift with usable output down to F3 33 Hz and the tight, accurate transient response sealed enclosures are loved for. Build it to the plan and this is what you can expect to measure.

Predicted frequency response of the Dayton Audio UMII15-22 Ultimax II 15" DVC Subwoofer 2 Ohms Per Coil sealed box

33 Hz

Extension (F3)

43 Hz

Tuning (Fc)

1.02

System Q (Qtc)

85 L

Net volume

117 dB

Max output

86 dB

Sensitivity

What you get

+Per-panel DXF cut files + a nested cut sheet for an efficient single-board cut
+Full-size 1:1 print-and-tape A4 templates (PDF) so you can build it accurately with no CNC
+STEP + STL 3D models so you can preview the exact box before you cut
+Printable cut list (CSV) with every panel + the driver cutout
+Separate grille cut file (DXF) + its own 1:1 A4 template, so you can cut the grille from a sheet of perforated mesh metal
+Recessed-hardware cut-outs built into the panels (2 side-handle recesses and the Speakon connector recess), centred and gasket-sealed, with the mounting bolts marked
+Predicted-performance charts (response, max SPL, excursion, impedance)
+Full internal & external dimensions
+Stacking system: marked foot positions + top alignment pockets with sealed backing plates, so identical boxes stack and self-locate (feet not included)

Inside the plan

Dayton Audio UMII15-22 Ultimax II 15" DVC Subwoofer 2 Ohms Per Coil Sealed Subwoofer Enclosure Plan with DXF Cut Files + 3D Model — cutaway showing the bracing

Dayton Audio UMII15-22 Ultimax II 15" DVC Subwoofer 2 Ohms Per Coil Sealed Subwoofer Enclosure Plan with DXF Cut Files + 3D Model — exploded view of every panel

Dayton Audio UMII15-22 Ultimax II 15" DVC Subwoofer 2 Ohms Per Coil Sealed Subwoofer Enclosure Plan with DXF Cut Files + 3D Model — CNC nest layout

Dayton Audio UMII15-22 Ultimax II 15" DVC Subwoofer 2 Ohms Per Coil Sealed Subwoofer Enclosure Plan with DXF Cut Files + 3D Model — 1:1 A4 print-and-tape template

Dayton Audio UMII15-22 Ultimax II 15" DVC Subwoofer 2 Ohms Per Coil Sealed Subwoofer Enclosure Plan with DXF Cut Files + 3D Model — render

Dayton Audio UMII15-22 Ultimax II 15" DVC Subwoofer 2 Ohms Per Coil Sealed Subwoofer Enclosure Plan with DXF Cut Files + 3D Model — animated views

Bracing that anyone can build (drill or CNC)

Inside, an interlocking egg-crate of window braces locks together with half-lap joints and glues to all six panels, stiffening the box and pushing its panel resonances well above the bass it plays. To stay rigid but acoustically open, every brace is lightened with a grid of **round holes sized to standard hole-saw diameters** (around 32 to 76 mm). That means you can bore them with cheap, off-the-shelf bits from any hardware store, in a fraction of the time it takes to jigsaw square windows out, and round holes are stronger because there are no sharp corners to crack. Prefer a CNC? The exact same holes are already in the DXF cut files, so the machine cuts them along with the panel outline in one pass. Either way the 1:1 paper templates mark every hole centre for you, and the driver, handle and amplifier/connector clearances are carved into the braces and verified in 3D so nothing ever fouls.

Dayton Audio UMII15-22 Ultimax II 15" DVC Subwoofer 2 Ohms Per Coil Sealed Subwoofer Enclosure Plan with DXF Cut Files + 3D Model interior bracing

Two ways to cut every part

Print & tape — no CNC needed

No CNC, no laser cutter, no problem. Every panel and brace also comes as a full-size 1:1 PDF, tiled across ordinary A4 paper. Print at 100%, butt the full sheets together edge-to-edge and tape them on the back (no trimming, no guesswork), then lay the template on your board, trace the lines and cut with a jigsaw or router. Every sheet has a printed 100 mm ruler so you can confirm the scale is spot-on before you cut, and each part comes with a one-page map showing exactly how its sheets line up. Got a CNC? Feed it the DXF files instead, and either way you build the very same box.

Or send it straight to a CNC

Every panel, brace and the grille ship as whole-millimetre DXF files, plus a nested cut sheet that arranges all the parts on a single board for an efficient, low-waste cut. Load the DXF into your CAM software (or hand it to a cutting service) and the machine cuts every outline, the driver cutout and the round brace holes in one pass — no measuring, no setup drawings, identical to the box in the 3D model.

Design specs

Design specifications
Driver	Dayton Audio UMII15-22 Ultimax II 15" DVC Subwoofer 2 Ohms Per Coil
Alignment	Sealed, Qtc 1.02
Net volume	85 L
Tuning	Fc 43 Hz · F3 33 Hz
External (W×H×D)	449 × 449 × 615 mm
Material	18 mm MDF/plywood
Max SPL	117 dB @ 59 Hz (900 W)
Sensitivity	86 dB @ 1 W / 1 m
Array coupling	+6 dB up to 192 Hz when arrayed (449 mm centres)
Handles	2x Penn Elcom H1105 recessed steel side handles (1 per side)
Connectors	Penn Elcom D0604 recessed back panel (2x Speakon)
Grille	2 mm inset grille on a 31 mm front lip, 8 support blocks (perforated steel or mesh, customer supplied)
Stacking	4x Adam Hall 4907TP rubber feet; 40 mm top pockets self-locate stacked boxes (panels carry the load, pockets sealed by glued backing plates)
Alignment	Manufacturer (85 L)
Group delay	7.6 ms @ Fc
Driver T/S	Fs 29.34 Hz · Qts 0.7014 · Vas 96 L · Xmax 24 mm · Pe 900 W

Hardware you'll need

The plan is cut to fit these exact parts, so order these and they drop straight in (every recess is built around their real measured dimensions):

Penn Elcom H1105 — 2 recessed steel side handles (sealing gasket included with the handle); the 1-per-side recesses are cut to this exact handle
Penn Elcom D0604 — recessed back-panel dish for 2x Speakon connectors; the cut-out is sized to this exact dish
Adam Hall 4907TP — 4x rubber stacking feet (38 mm dia); the foot marks and 40 mm top pockets are sized for these
Perforated mesh metal sheet — any perforated steel or aluminium sheet; cut the grille to size from the included grille DXF / 1:1 A4 template
Dayton Audio UMII15-22 Ultimax II 15" DVC Subwoofer 2 Ohms Per Coil — the subwoofer driver itself (not included)