{"inputs":{"boxVolumeL":50,"portDiameterCm":10,"tuningHz":32,"tempC":20,"coneAreaCm2":null,"peakExcursionMm":null},"result":{"tempC":20,"speedOfSoundMs":343.21462268256795,"portAreaCm2":78.53981633974483,"endCorrectionCm":7.3165,"acousticLengthCm":45.771142084681586,"cutLengthCm":38.45464208468158,"tooNarrow":false,"verdict":"Buildable","minDiameterCm":1.5984962722720972,"lengthToDiameter":3.845464208468158,"portVolumeL":3.020220526741514,"peakVelocityMs":null,"machFraction":null},"provenance":{"method":"Helmholtz resonance of the box (cavity) and port (neck), solved for length: acoustic length S/(k^2*Vb) with k = 2*pi*fb/c, minus the end corrections of both port ends, 0.85*r for the outer end flush with the baffle and 0.6133*r for the inner end free in the box (1.4633*r, the 0.732*D of vented-box port formulas; r = sqrt(S/pi)). c = 331.3*sqrt(1 + T/273.15). The smallest diameter that reaches the tuning is d_min = 8*pi*1.4633*fb^2*Vb/c^2. Peak port air speed = (Sd/S)*xmax*2*pi*fb. Straight round port of constant diameter in a rigid box; no flare, no slot outline, no stuffing. Checked in the site test suite against the resonance run backwards from the cut length and against the 0.732*D literature form. Pure mathematics - nothing is fetched and nothing is recalled.","canonicalUrl":"https://makerportal.ai/lab/port-length-calculator"},"license":"free-with-attribution"}