Bass Surface Drum · 800 mm OD frame drum, 50 Hz sub-bass
Status
Private reviewV5 blueprint — not yet a measured build.
Family
drum · frame-drum · low-tension circular membrane
Release gates
Private until human frame-drum player review.
Private until metal-forming safety/process review.
Private until supplier/IP/public-release review.
Private until measured prototype validation data exists.
Private until at least one capstone photo set is shot.
01 · OverviewBass Surface Drum
A very large (800 mm OD) single-head frame drum with a rolled sheet-metal frame instead of the traditional bent-wood hoop. The membrane is a thick natural-skin head, tuned to a sub-bass acceptance band centered at 50 Hz (~G1) for cinematic boom and slow processional pulse.
The sheet-metal frame integrates two rolled-edge features in the same forming pass: a 4 mm-radius outward bearing flange at the top, and a 6 mm rolled-in stiffening bead at the bottom (anti-ovalization stiffness without a separate hoop ring). This replaces a separately-fabricated wood bearing edge and steam-bent hoop.
The packet covers the full path from sheet stock to first head-mount: parametric design, Wolfram acoustic model, SolidWorks plan, flat patterns, BOM, fabrication plan, assembly manual, and validation gates. A future round builds V0 and writes measured data back into validation.csv.
Wolfram model: the bass-surface-drum-starter.wl file in this repo predicts Bessel modes (0,1)..(2,2), solves for rim tension T ≈ 2960 N/m from target f_01 = 50 Hz, totals radial pull ≈ 7064 N, computes worst/best ovalization bounds on the rolled-steel frame, and runs head/tension sensitivity.
