Dayton Audio Reference RSS390HO Dual Box: Sealed 15" Wedge Enclosure Dual 15" Sealed enclosure

The Reference RSS390HO, yes, in the RSS390HO-4 (single 4 ohm) version. The baffle is cut to 14.00 in for Dayton's 15.29 in frame. The 7.01 inch motor clears the cabinet with 4.13 inch to spare. Run two of the same coil so the chambers match.

Any other 15, no. The airspace is engineered around the Reference RSS390HO's own Qts and Vas, and a different woofer that happened to drop into the hole would not see the alignment printed on this page.

1.53 cubic feet net per chamber on Dayton's published figures: the RSS390HO-4 (single 4 ohm) reads Qtc 0.707 with resonance at 47.5 Hz and half power at 47.5 Hz. That is spread either side of maximally flat: the lower-Q coil a little drier, the higher-Q coil a little punchier.

The 7.01 inch mounting depth sets the minimum cabinet depth here, so the airspace is what the motor allows rather than a free choice.

Dayton rates the Reference RSS390HO at 800 watts RMS per driver, so target 560 to 800 watts RMS per driver at the final load.

Dayton sells the RSS390HO as RSS390HO-4 (single 4 ohm); a matched pair should share a coil. A pair of single 4 ohm drivers lands on 2 ohms in parallel or 8 ohms in series. Anything under 1 ohm, and many amplifiers at 1 ohm, is outside what the amplifier is built for, so series wiring is the safe default. Confirm your amplifier's minimum stable impedance first.

The seat-side face carries a 20 degree rake that matches the lean of a factory rear seat back, so the cabinet sits flush against it and the cargo space in front stays usable. The baffle is the vertical trunk-lid-side face, so the drivers fire rearward into the trunk cavity.

The trunk acts as an acoustic extension for the sealed box, and the cabin adds real output below 50 Hz, so in-vehicle response runs deeper than the anechoic 47.5 Hz on this page.

Two drivers sharing one sealed volume load each other: each driver's compression stroke becomes the pressure the other works against, which blurs the alignment either would have alone. A bonded full-height 3/4 inch divider gives each driver its own 1.53 cubic feet and its own polyfill.

It also means a failure in one driver does not unload the other, and the alignment on this page is the alignment in each chamber, not an average across a shared box.

Anechoic F3 is 47.5 Hz per chamber. Below Qtc 0.707 the rolloff is gentle and F3 sits above fc, which is what an over-damped sealed box does.

Those figures exclude cabin gain. In a car the cabin's transfer function adds real output below 50 Hz, so in-vehicle response runs deeper than the numbers above.

No. Polyfill is already installed in both chambers as a light wall lining to control internal reflections, and the quantity is chosen so it does not change the acoustic volume.

Do not add more. Packing a sealed box with fill makes it behave as though it were larger, which walks the alignment away from the 1.53 cubic feet per chamber this cabinet was built to.

No driver. This is an enclosure only. You receive the cabinet finished in plush black carpet with the gloss black acrylic baffle insert, one side-mounted pre-wired terminal cup to both positions, the polyfill lining already in place, and stainless machine screws, with the threaded inserts already pressed.

The inserts are pressed at the shop on Dayton's published bolt circle for the Reference RSS390HO, so the driver bolts straight in. The pair of Dayton Audio Reference RSS390HO is purchased separately, and the cabinet is cut direct fit to it, not a general purpose 15 inch box.