Portable speaker builds · Apache · Pelican Vault
A build sheet for turning a rugged hard case into a portable speaker. Real interior dimensions, real driver specs, and the arithmetic that tells you what actually fits before you cut a hole in a $200 case.
Every driver, amp and battery row carries a manufacturer link and an Amazon link. Blanks mean the manufacturer does not publish that number — not that we forgot.
What is in here
The awkward part of a case build is not choosing a driver. It is that the case fixes your baffle area, your internal volume and your mounting depth all at once, and none of those numbers appear on the retail page.
01 / CASES
Exterior and interior L×W×D, lid and base depth, wall thickness. Interior is the only number that matters when you are laying out cutouts.
02 / DRIVERS
Full-range, coaxial, subwoofer and passive radiator. Flange diameter, cutout, mounting depth, impedance, RMS, sensitivity, Vas.
03 / POWER
Class-D boards with their real supply window. A 48 V board on a 24 V pack is not underpowered, it is silent.
04 / FIT
Voltage, load, power, volume and physical clearance, each scored separately so you can see which one failed.
How the recommender works
Choose the case. The site works out the usable baffle rectangle on the front face, the depth left behind that baffle after electronics, and marks which drivers in the library physically fit. Drivers that will not clear are still listed, crossed out, so you can see why.
Pick the front driver and, if you want one, a passive radiator for the back. The volume calculation updates with driver displacement, and the amp list is filtered to boards whose supply window takes the pack you intend to use.
Pick the board and the battery. You get a 0–100 fit score, the per-criterion breakdown, and a plain-language list of what has to change if something does not work.
Maximum drivers per case
Circular flanges packed on the usable rectangle, with a border for the case wall and a gap between frames. Two mounting methods, because they give different answers.
0.75″ clear border, 0.25″ between flanges. The border keeps bolt heads off the latch ribs and the wall radius.
0.30″ border, 0.20″ between flanges. A plate spans the opening, so it recovers most of the lost area and lets you run three or four small drivers instead of one large one.
Already have a list?
Paste product names or links, one per line. The checker matches them against the library and runs the compatibility rules — including the classic 36 V amp on a 24 V pack.
What this is not