Subwoofer Box Design & Wiring

Clean Screen Apps

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About this app

See your subwoofer box in 3D before you cut a board: your size, your subs and your ports, drawn from your numbers with the sizes on it. BassMath does the math of every subwoofer build offline: box volume and cut sheet, port length and box tuning, wiring to the load your amp wants, and the power wire and fuse for your amp. No sign-up, no subscription pop-up after you type in all your specs. One small banner at the bottom, no pop-up ads.

SUBWOOFER BOX CALCULATOR WITH CUT SHEET
• 3D preview of your box with the subs and the ports: drag to turn it, tap to show or hide the sizes.
• Sealed or ported. Type the outside size and get the net volume, or type the volume your sub wants and the height and depth of your space and get the width that fits.
• Takes off the sub displacement, the port and the bracing. Double baffle. 3/4" MDF, 18 mm or any thickness.
• Wedge boxes with a slanted back for truck cabs.
• Cut sheet in fractions to 1/16" (or mm): every panel, how many, what size. Name each build so you find it later.

PORT LENGTH CALCULATOR
• Round, aero (flared) and slot ports. Length for 32 Hz or any tuning, or what a port you already built tunes to.
• Port area per cubic foot against the usual 12–16 sq in rule, and how much box the port takes up, slot wall included.
• The Helmholtz formula with end correction and your numbers shown on every result.

SUBWOOFER WIRING & OHM LOAD
• 1 to 4 subs, single or dual voice coil, any impedance including 1 ohm, 0.5 ohm and decimals.
• Every balanced way to wire them, each with a wiring diagram and step-by-step: series, parallel, series-parallel.
• Enter your amp's minimum stable load and see which layouts it can run, and the lowest one for the most power.

AMP POWER, WIRE & FUSE
• Amp to sub matching: under-powered, good match or over-powered, from RMS ratings.
• Amp wire gauge: current draw from RMS watts and amp class, fuse size, power and ground gauge for your run, copper or CCA, voltage drop.
• Big 3 upgrade gauge from your alternator output.
• Current draw vs alternator: how many amps your system pulls and whether the alternator keeps up.

CHARTS
• Box size chart: typical sealed and ported volume for 6.5", 6x9, 8", 10", 12", 15" and 18" subs, 1 to 4 subs.
• Amp wire gauge chart for 500 to 5,000 watt amps at 10, 15 and 20 ft.
• Box volume calculator and converter: cubic feet, liters, cubic inches.

BUILT FOR THE GARAGE
• Inches and feet with fractions, or millimeters and liters. Type 15 1/2, 3/4", 18 mm, 50 L or 1.5 ft3 in any field.
• Big app keypad option, keep-screen-on, dark and high-contrast themes.
• English and Spanish. History of your builds and calculations. Share any result as text.
• No account. Nothing leaves your phone. Works without signal.

WHY CLEAN SCREEN APPS — I got tired of apps that throw full-screen ads at you in the middle of a job, so I build apps with no pop-up ads. BassMath is another one: one small banner at the bottom, never over your numbers, and a one-time "Remove ads" option. No subscription, ever.

Questions or ideas? [e-mail]

Results are starting points: your sub's manual wins for box size and tuning. Wire and fuse sizes are conservative guidance, not a safety rating; follow your amp and vehicle manuals.

What’s new

New in this update:
• Sub box: share a free cut sheet PDF with every panel size, what was taken off for the wood thickness, the port tube or slot board, and a simple layout on 4 × 8 sheets.