Performance Optimized Wedge Sealed Dual 15" Enclosure Audiomobile Encore 4415 · Dual 15" Sealed enclosure

The Encore 4415, yes: the baffle is cut to Audiomobile's 14.00 inch cutout, the recess to its 15.50 inch frame, and the raked rear panel clears the 5.9 inch motor with 4.66 inch to spare. The Encore ships in one version, dual 4 ohm, so there is no coil variant to choose. Run two of them so the chambers match.

Any other 15, no. The airspace is engineered around the Encore 4415's 0.625 Qts and 63.70 liters of Vas, and a different woofer that happened to drop into the hole would not see the alignment printed on this page.

1.50 cubic feet is the middle of Audiomobile's 1.25 to 1.8 cubic feet sealed range for this driver. The Encore 4415 is a high-Qts design: Qts 0.625 against 2.25 cubic feet of Vas means it lands at Qtc 0.94 even at the top of Audiomobile's range and 1.05 at the bottom, and a maximally flat 0.707 box would take about 8 cubic feet, which no trunk wedge can hold.

In this cabinet it sits at Qtc 0.988, resonance 51.1 Hz, half power 40.4 Hz, with a 1.2 dB rise centred near 73 Hz. That is the punch Audiomobile builds the Encore for, and the performance graph on this page shows the real curve rather than a flat one.

Audiomobile rates the Encore 4415 at 1000 watts RMS per driver and 2000 watts maximum, so target 700 to 1000 watts RMS per driver at the final impedance. Each driver carries two 4 ohm coils: parallel for 2 ohms (1.71 ohms DC, the way Audiomobile measured it), series for 8 ohms.

Wire both drivers identically so the chambers share power evenly. Both drivers in parallel and the pair paralleled is 1 ohm, which needs an amplifier rated for it; either mixed arrangement, parallel within and series across or series within and parallel across, gives 4 ohms and is the safe answer on any amplifier.

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's transfer function adds real output below 50 Hz, so in-vehicle response runs deeper than the anechoic 40.4 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 smears transients and blurs the alignment either would have alone. A bonded full-height 3/4 inch divider gives each driver its own 1.50 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 40.4 Hz per chamber with system resonance at 51.1 Hz. At Qtc 0.99 the response rises 1.2 dB around 73 Hz before rolling off, so half power sits below resonance; that lift is the Encore's designed-in impact.

Those figures exclude cabin gain. In a car the transfer function of the cabin adds real output below 50 Hz, so in-vehicle response runs deeper than the numbers above. Audiomobile's sheet publishes no in-box F3 for this driver.

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 1.50 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 the threaded insert kit with stainless machine screws.

The inserts ship loose on purpose: Audiomobile publishes no mounting hole locations for the Encore, so you set the driver in the recess, mark its holes, drill and press the inserts. The pair of Audiomobile Encore 4415 is purchased separately, and the cabinet is cut direct fit to it, not a general purpose 15 inch box.