Sine Design

Dayton Audio ND65-4

fullrange · EBP 132 → suits a ported box · nominal (full) — Dayton Audio datasheet (https://www.daytonaudio.com/images/resources/290-204-dayton-audio-nd65-4-specifications.pdf)

Thiele/Small parameters

Fs (resonance)89.5 Hz
Qts0.61
Qes / Qms0.68 / 5.56
Vas0.5 L
Re / nominal Z3.5 Ω / 4 Ω
Xmax3.5 mm
Sensitivity79.3 dB (1 W/1 m, calc); 83 dB (2.83 V/1 m, mfr)
Power handling15 W

Published (nominal) values, params full — verify by measurement (DATS/REW) before building.

Datasheet (PDF) ↗ — manufacturer-hosted

Recommended enclosures

Sealed (Qtc 0.707) — Vb1.5 L
Sealed — Fc / F3103.7 / 103.7 Hz
Ported (suggested) — Vb2.1 L
Ported — Fb / F358.6 / 50.8 Hz
Open in designer →Use my measured parameters →Buy at Parts Express →

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About this driver

The Dayton Audio ND65-4 is a 2″ fullrange with a free-air resonance of 89.5 Hz and a total Q (Qts) of 0.61. Its efficiency-bandwidth product (EBP) of 132 points toward a ported alignment. In a 1.5 L sealed box it reaches an F3 of 103.7 Hz (Qtc 0.707); a suggested 2.1 L box tuned to 58.6 Hz extends to about 50.8 Hz. See the sealed vs ported guide for how to choose.

Recommended partners

modeled estimate

The tweeters below pair well with the Dayton Audio ND65-4 in a two-way design — each grade is a modeled estimate of the crossover match, with a suggested crossover point. Open any pair in the guided builder to design the crossover and total the parts.

Modeled estimate from T/S + geometry — no measurements. The verdict is robust; it improves with measured FRD/ZMA data.

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