Performance Optimized Down Fire Wide Sealed Dual 10" Enclosure Hertz Mille Pro MPS 250 · Dual 10" Sealed enclosure

Because it is only 12 inches deep. The standard Performance Optimized Down Fire platform is 30 wide by 15 deep, and this application needs a cabinet that fits a space three inches shallower than that.

The airspace has to come from somewhere, so the cabinet runs 41 inches long instead of 30 and stands 6.8125 inches tall, with each driver still in its own chamber. If you have 15 inches of depth, the standard cabinet is the pick; if your space is long and shallow, under a rear bench or on a narrow cargo floor, this is the shape that fits.

The standard cabinet is 30 x 15 x 7.6875 inches and gives each driver 0.547 cubic feet net. This cabinet is 41 x 12 x 6.8125 and gives each driver 0.502 cubic feet net, Hertz's 14.2 liters. The standard box runs slightly lower Qtc per chamber, 0.659 against 0.677 on the S2 and 0.739 against 0.758 on the S4; otherwise they behave alike. The choice is about shape: the standard box needs 15 inches of depth, this one needs 12 inches of depth and 41 inches of run.

Each chamber holds Hertz's own sealed recommendation of 14.2 liters per driver. At 0.502 cubic feet net per chamber: MPS 250 S2: Qtc 0.677, Fc 46.2 Hz, F3 48.4 Hz. MPS 250 S4: Qtc 0.758, Fc 45.8 Hz, F3 42.9 Hz. The S2 is the tighter alignment and the S4 reaches lower.

Those are anechoic figures. Firing into the floor, the sealed rolloff meets rising cabin gain, so in-car response runs deeper than the numbers above.

One side-mounted Proline X terminal cup with a single pair of posts, pre-wired in 12 gauge OFC to both driver positions in parallel. You do not wire the two chambers separately at the amplifier.

Both MPS 250 models are single voice coil, so there is no coil decision at the driver. Your load is set by the model, 2 ohms each for the S2 or 4 ohms each for the S4, and how the pair resolves through the cup. Confirm it against your amplifier's minimum stable load.

On this size the S2 is the better damped driver, Qts 0.41 against the S4's 0.48, and the S4 reaches lower with more motor force. Pick on the load your amplifier wants first, then on character. Whichever you choose, use two of the same model; this pattern reverses on the 12 inch MPS 300.

Side mounted, and there is one cup serving both chambers rather than one per chamber. Every Proline X Performance Optimized enclosure uses a side mounted terminal cup, and on a down fire cabinet that keeps the connection accessible with the enclosure installed, since both baffles face the floor. The cup is our Proline X ABS and carbon fiber composite unit, recessed, with stainless hardware, copper ring terminals, and 12 gauge OFC pre-wired to both driver positions in parallel.

V-groove and dado joinery, CNC cut on ShopSabre routers from Langboard Elite MDF. Every panel joint is a machined interlocking groove that mechanically locks the panels before adhesive is applied, which keeps both chambers airtight under sustained pressure cycling. Corners are square, the Down Fire series standard, with no radii.

The front baffle is a double layer at 1.5 inches, with the outer layer machined as a flush recess so each driver bolts to the inner layer. A full-height bonded 3/4 inch divider separates the chambers and ties the front and rear walls together across the 41 inch span. Polyfill is installed as a light wall lining. Assembled and inspected in Tullahoma, Tennessee.

No. This listing is for the enclosure only. Bring your own pair of Hertz Mille Pro MPS 250 S2 or MPS 250 S4, two of the same model. The cutouts and mounting depth are direct fit at both positions.