Dayton Audio RSS390HF-4

15″ subwoofer · 4 Ω · 500 W RMS

19.5 HzFs, resonance

0.43Qts

7.49 ft³Vas

0.55″Xmax

500 WRMS

Source	parts-express.com · manufacturer data
Checked against source	October 2026
Thiele/Small parameters	complete
Mounting dimensions	3 of 4 — missing: magnet diameter; the designer will use an estimate

Recommended box

For a sedan, one sub, 500 W. It’s the same math as the designer’s step-by-step mode, where you can fit the box to your space, vehicle and amp and get plans, a cut sheet and DXF.

Sealed

smaller, tighter

2.93 ft³ (83 L)

Net volume

Manufacturer spec: 2.90 ft³ · source

Bass character (Qtc)	Tight and punchy · 0.81
Fc	37 Hz
F3 (−3 dB, no cabin gain)	35 Hz
Example box (outside)	31 1/2″ × 18 1/8″ × 12 1/8″

Open sealed box in designer

Ported

deeper, louder

3.00 ft³ (85 L)

Net volume

Manufacturer spec: 3.00 ft³ · source

Tuning (Fb)	30 Hz
Port	slot 1 9/16 × 16 11/16″, 21 3/4″ long
Port velocity at 500 W	58 ft/s
F3 (−3 dB, no cabin gain)	30 Hz
Example box (outside)	31 1/2″ × 18 1/8″ × 13 7/8″

Open ported box in designer

Deeper: 4.98 ft³ (141 L) tuned to 26 Hz, 31 1/2″ × 18 1/8″ × 20 15/16″ outside — a bigger box with flatter deep bass. Open in the calculator

Where to buy Amazon

Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Size	15″
Voice coils	4 Ω
RMS power	500 W
Fs	19.5 Hz
Qts	0.43
Qes	0.5
Qms	3.02
Vas	7.49 ft³

Re	3 Ω
Sd	128.6 in²
Xmax	0.55″
Vd	70.9 in³ calc.
Mms	306 g calc.
BL	15 T·m calc.
EBP	39 — suits sealed calc.
Sensitivity, 1 W / 1 m	87 dB calc.

Mounting dimensions

Cutout diameter	14 1/16″
Mounting depth	7″
Overall diameter	15 5/16″

“≈” means the value isn’t in the spec sheet and a typical value for the size is used; “calc.” means it’s calculated from the published parameters. Check the manufacturer’s spec sheet before you build.

Data sources

parts-express.com/Dayton-Audio-RSS390HF-4-15-Reference-Series-HF-Subwoofer-4-Ohm

Other Dayton Audio 15″ models

Dayton Audio DCS385-4 15″ · 4 Ω
Dayton Audio MX15-22 15″ · dual 2 Ω
Dayton Audio RSS390HO-4 15″ · 4 Ω
Dayton Audio SS15-22 15″ · dual 2 Ω
Dayton Audio UM15-22 15″ · dual 2 Ω
Dayton Audio UMII15-22 15″ · dual 2 Ω

Similar 15″ subwoofers from other brands

Close in Fs, Qts and Vas — a box of similar volume will suit them.

MTX Audio RT15-04 2.93 ft³ sealed · 3.81 ft³ ported
RE Audio SRX15 D4 2.58 ft³ sealed · 3.71 ft³ ported
Hifonics BRZ15D4 (Brutus 15" DVC 4ohm) 2.83 ft³ sealed · 3.67 ft³ ported
Kicker Comp 15" 4-Ohm SVC (43C154) 2.75 ft³ sealed · 3.67 ft³ ported
Earthquake Magma-15X 1.27 ft³ sealed · 4.10 ft³ ported
PowerBass M-1504 2.75 ft³ sealed · 3.57 ft³ ported

FAQ

What box does the Dayton Audio RSS390HF-4 need?

Recommended net volume: 2.93 ft³ sealed, 3.00 ft³ ported tuned to 30 Hz — for one sub in a sedan at 500 W. Fit the box to your space and amp in the free calculator, with plans and a cut sheet.

What are the Dayton Audio RSS390HF-4 Thiele/Small specs?

Fs 19.5 Hz, Qts 0.43, Vas 7.49 ft³, Xmax 0.55″, Sd 128.6 in².

What is the Dayton Audio RSS390HF-4 mounting depth?

Mounting depth is 7″, cutout diameter 14 1/16″. The inside depth of the box must exceed the mounting depth by at least 1″.

How much power does the Dayton Audio RSS390HF-4 handle and how do I wire it?

RMS power rating: 500 W. Wiring for several subs and amp power — in the wiring calculator.