Performance Optimized Down Fire Sealed Dual 10" Enclosure Sony XS-W104ES · Dual 10" Sealed enclosure

The XS-W104ES, yes. The baffle is cut to 9.21 in (234 mm), Sony's published cutout, under the 279 mm (10.98 in) frame. Some dealer listings quote 9-1/16 in; that is 4 mm short of Sony's figure. The 5.39 inch motor clears the cabinet with 4.16 inch to spare, and Sony sells the XS-W104ES in one version, a single 4 ohm coil, so there is no variant to choose. Run two so the chambers match.

Any other 10, no. The airspace is engineered around the XS-W104ES's 0.49 Qts and 23.3 liters of Vas, and a different woofer that happened to drop into the hole would not see the alignment printed on this page.

It is the Butterworth volume on Sony's published Fs 39.6 Hz, Qts 0.49 and Vas 23.3 liters: system Qtc 0.707, maximally flat, with resonance and half power both at 57.1 Hz. Sony's own sheet recommends 1.01 cubic feet sealed, which reads Qtc 0.66 on the same figures; this cabinet is built to the flatter Butterworth box.

One caveat: a review sample measured after break-in read Qts 0.43 and Vas near 33 liters, looser than Sony's sheet. On those numbers this cabinet reads Qtc 0.68, a touch more damped. Either way it is a well-behaved sealed alignment.

Sony rates the XS-W104ES at 450 watts RMS per driver to CTA-2031 and 1800 watts short-term maximum, so target 315 to 450 watts RMS per driver at the final load.

Each XS-W104ES has a single 4 ohm voice coil (3.8 ohms DC). Two in parallel present 2 ohms; two in series present 8 ohms. Wire both the same way, and check that your amplifier is rated for the load you choose. Confirm your amplifier's minimum stable impedance first.

The cabinet is 10.30 inches tall measured in the down fire position, and that figure excludes the standoffs. The standoffs hold 1.75 inches under the baffle, so plan your space around a finished stack of roughly 12.05 inches.

The footprint is the standard Performance Optimized down fire platform, 30.00 inches wide by 15.00 deep. Height is the only dimension solved to the driver.

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 0.76 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 57.1 Hz per chamber with system resonance at 57.1 Hz. At Qtc 0.71 the response is maximally flat into the rolloff, so F3 and fc coincide.

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 0.76 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, one side-mounted pre-wired terminal cup to both positions, the polyfill lining already in place, the standoffs, and a threaded insert kit with stainless machine screws.

The inserts ship loose on purpose: Sony prints no bolt circle for the XS-W104ES, so you set the driver in the recess, mark its holes, drill and press the inserts. The pair of Sony XS-W104ES is purchased separately, and the cabinet is cut direct fit to it, not a general purpose 10 inch box.