Fs, Qts, Vas are the core Thiele/Small parameters. Ripple and group-delay
optimization use these alone. Enter more on the Advanced tab for SPL,
excursion, and cone-displacement calculations.
Driver Mounting
Driver displacement (magnet + basket volume) is subtracted from net internal volume.
Estimated from cone diameter & mounting depth when not manually specified.
Enclosure Type
External Dimensions
Volume Breakdown
Cutsheet Preview
Tuning Frequency
AUTO-TUNE searches Vb and Fb jointly to minimize in-band ripple while
maintaining group delay ≤ target. Port displacement is included in the search loop so
the final net volume equals what you set here.
Port Geometry
Port Velocity & Chuffing
Port velocity should stay below ~17 m/s (5% Mach) at full power to avoid audible
chuffing. Aim for ≤ 25 m/s (7% Mach) absolute maximum.
Extended T/S (optional)
Motor & Cone
Power Handling
Solver Precision
Auto-tune uses a 2D golden-section search over (Vb, Fb) with adaptive bounds. Runs on
CPU — the full sweep is < 30 ms typical. GPU acceleration isn't needed at this
problem size; we'd spend more on kernel dispatch than math.
FREQUENCY RESPONSE
Hz
cu·ft
××in
W
Analysis // LIVE
Alignment Metrics
Group Delay Window (audibility vs. tuning)
Blauert & Laws (1978): the audibility threshold for group-delay
below 100 Hz is ~20-25 ms. Under 15 ms is "excellent SQ"; 15-20 ms is "good"; 20-25 ms
is "fair — detectable on transients"; above 25 ms is "poor — smearing audible".
Sealed boxes always win here.
▸ Audibility reference
Reference & Qtc
Compare Builds (Hold a snapshot)
Cut-Sheet (for the lumber yard)
Export
About the Math ▸
Vented response uses the Thiele 4th-order transfer function with
system Q derived from driver Qts, Vas/Vb ratio, and tuning h = Fb/Fs. Sealed uses
2nd-order closed-box alignment. Group delay is derived analytically from the transfer
function's phase. Port length uses Small's end-correction formula with effective
radius adjustment for rectangular and flanged ports.
Add New Driver
✕
* = required. Fs, Qts, and Vas are the minimum needed for alignment
modeling. Xmax, Re, Qes, Qms, BL, Mms, Le, Sd improve SPL / excursion / impedance accuracy.
Leave fields blank if unknown — the solver will estimate them.