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Proline X PO 10TW-S W MP sealed wedge enclosure, product photos pending. Placeholder graphic reading Photos Coming Soon.

Performance Optimized · Datasheet

Performance Optimized Wedge Wide Sealed Triple 10" Enclosure Hertz Mille Pro MP 250 · Triple 10" Sealed enclosure

Net volume
1.159 cu ft per driver, 3.48 cu ft total, after both dividers and an estimated 0.069 cu ft displacement per driver
Max mounting depth
5.55 in required; 5.46 in clearance above the motor against the raked rear panel
External dimensions
40 in W × 17 in at the seat face H × 17.50 in at the base D
Front baffle
1.5 in double baffle, outer layer machined as a flush recess
Buy at Audio IntensityFactory-direct, ships from Tullahoma
Hertz Mille Pro MP 250Buy at Audio Intensity
  • Best For: Triple Hertz Mille Pro MP 250 SUV Cargo-Floor Builds
  • Net Volume: 1.159 cu ft per Driver (3.48 cu ft Net Total)
  • Driver Match: Three Hertz Mille Pro MP 250 (Dual 2 Ohm / Dual 4 Ohm), matched
  • Construction: 3 Chambers | 40" Wide Wedge | V-Groove/Dado | Double 1.5" Baffle | 3 Terminal Cups

Spec of record

Technical specifications

SpecificationValue
SeriesProline X Performance Optimized Wedge Wide
Compatible DriverHertz Mille Pro MP 250, quantity 3, matched. Direct fit
ConfigurationTriple 10 inch sealed wedge, 3 chambers, 1 driver per chamber
Mounting PositionSUV cargo floor, raked face against the rear seat back
Firing DirectionRearward toward the liftgate. Not a down fire design
External Width40 in
External Height17 in at the seat face
External Depth17.50 in at the base, tapering to 11.31 in at the top
Internal Volume, Gross3.84 cu ft total
Internal Volume, Net Acoustic1.159 cu ft per driver, 3.48 cu ft total, after both dividers and an estimated 0.069 cu ft displacement per driver
Driver Mounting Depth5.55 in required; 5.46 in clearance above the motor against the raked rear panel
Alignment Per DriverMP 250 10" D2.3 Qtc 0.717, fc 39.8 Hz, F3 39.3 Hz; MP 250 10" D4.3 Qtc 0.697, fc 37.7 Hz, F3 38.2 Hz anechoic
Woofer Openings3 at 9.291 in
Woofer LayoutOne row across the face
Frame Outer Diameter10.551 in
Fs / Qts / Qes / Qms30.0 Hz / 0.540 / 0.600 / 5.920
Vas / Sd / Xmax25.0 L / 355 cm2 / 17 mm
Driver Power Handling600 W RMS per driver, 1800 W RMS for the set of 3 (thermal rating)
Recommended Amplifier350-500 W RMS per driver, 1,050-1,500 W RMS for the full set
Parameter SourceHertz published specifications
MaterialLangboard Elite MDF
ConstructionCNC cut, V-groove and dado joinery
Panel Thickness0.75 in
Front Baffle1.5 in double baffle, outer layer machined as a flush recess
Internal BracingTwo full-height 3/4 in dividers
Driver MountingThreaded inserts, stainless machine screws included
Terminal CupsThree Proline X ABS and carbon fiber composite, on the rear panel, one per chamber, pre wired 12 gauge OFC
Acrylic InsertGloss black acrylic baffle insert standard
DampingLight polyfill wall lining in every chamber, does not alter acoustic volume
CarpetPlush black
Shipping Weight81 lb
Warranty1 Year Limited
Built InTullahoma, Tennessee

Modelled response

Performance in this enclosure

Net airspace
1.159
cu ft per driver
System Qtc
0.70–0.72
sealed
Half power
38.2–39.3
Hz · F3
Xmax at
312
W RMS per driver · no filter
With 25 Hz subsonic
503
W RMS per driver · +61%
Amplifier, per driver
350–500
W RMS recommended
This enclosure holds 1.159 cu ft net per driver. In it the Hertz MP 250 10" D2.3 runs a system Qtc of 0.70–0.72 with half power at 38.2–39.3 Hz, and the cone reaches its 17.0 mm travel limit at 312 W per driver, below the driver’s 600 W thermal rating, so travel is what stops you here, not heat. Run a subsonic filter at 25 Hz and that becomes 503 W per driver — +191 W, or 61 percent more power for the same 17.0 mm of travel.

00Sizing the amplifier

Every wattage on this panel is per driver. This cabinet holds three, so the amplifier feeds all three at once.

Per driver 350–500 W RMS  ×  3 drivers  =  full set 1,050–1,500 W RMS
Look for a mono amplifier rated 1,050–1,500 W RMS at the load your coil version wires to. Travel sets the top here, not heat: past 503 W per driver the cone runs beyond Xmax even with the subsonic set, under the driver’s 600 W thermal rating. The top of the range needs the 25 Hz subsonic filter set; without it, keep each driver under 312 W, where the cone reaches Xmax unfiltered. Below the bottom of the range it will play, just with less headroom; above the top you are buying power the drivers cannot use.

01Is it a sealed driver?

Efficiency bandwidth product places the motor before anything else is decided.

EBP = Fs ÷ Qes = 50.0–50.9
SEALED 0–50 TRANSITION 50–100 PORTED 100–150 0 50 100 150 Dual 2 Ohm 50.0 Dual 4 Ohm 50.9
Dual 2 Ohm · EBP 50.0Dual 4 Ohm · EBP 50.9
At 50.0–50.9 the MP 250 10" D2.3 sits in the transition band, not the sealed band. That is not a mismatch: a transition motor works in either alignment, and sealed buys a smaller box and a gentler roll-off at the cost of some low-end output. Stage 02 shows what this airspace actually does with it.

02What the box does to it

1.159 cu ft against a 25.0 L Vas.

α = Vas ÷ Vb = 0.76  ·  Fc = Fs√(α+1) = 38–40 Hz  ·  Qtc = 0.70–0.72
20 30 50 70 100 150 200 +6 +0 -6 -12 -18 -24 FREQUENCY · Hz LEVEL · dB −3 dB
Dual 2 Ohm · Qtc 0.72, Fc 40 Hz, F3 39.3 HzDual 4 Ohm · Qtc 0.70, Fc 38 Hz, F3 38.2 Hz
The box lifts resonance from 27.0–30.0 Hz free-air to 38–40 Hz and half power lands at 38.2–39.3 Hz, anechoic, before any cabin gain. Figures are Hertz’s published parameters; Qes and Qms reproduce the printed Qts. This cabinet holds three drivers in three separate sealed chambers of 1.159 cubic feet each, the volume plotted here.

03The watts that reach Xmax (in this enclosure)

Travel scales with the square root of power, so there is one wattage that puts the cone exactly on 17.0 mm — and a bigger one once a subsonic filter stops it wasting travel below the passband.

PXmax = 312–383 W per driver unfiltered  →  503–573 W with a 25 Hz subsonic
20 30 50 70 100 150 200 0 4 8 12 16 20 FREQUENCY · Hz CONE TRAVEL · mm PAST LINEAR TRAVEL · Xmax 17.0 mm 312 W reaches Xmax here
Dual 2 Ohm · 383 W, no filterDual 4 Ohm · 312 W, no filterDual 2 Ohm · 573 W with subsonic at 25 Hz, 24 dB/octDual 4 Ohm · 503 W with subsonic at 25 Hz, 24 dB/octXmax 17.0 mm one-way
Every trace touches the limit and no further, because each is drawn at the exact power that puts that coil on 17.0 mm. Unfiltered that is 312 W per driver, reached first at 20 Hz. It sits under the 600 W the driver can take thermally, so the enclosure sets the ceiling, not the voice coil. The dashed traces are the same driver behind a subsonic filter at 25 Hz, 24 dB/oct: stopping the cone wasting travel below the passband lets it take 503 W per driver before hitting the same 17.0 mm. That is 61 percent more amplifier for the price of one filter setting.
ParamValueUnitNote
Fs30.00 / 27.00Hzfree-air resonance
Qts0.540 / 0.500Dual 2 Ohm / Dual 4 Ohm
Vas25.00 / 31.00Lequivalent compliance
Sd354.6cm²effective piston area
Xmax17mmone-way linear travel
Pe600Wcontinuous RMS
SPL82.4dB1 W / 1 m, derived from T/S

Driver parameters as published by Hertz MP 250 10" D2.3 / MP 250 10" D4.3 published specifications. Curves computed against this enclosure’s actual net airspace.

From the shop floor

Installer's take

Start with the size. 1.159 cubic feet per driver puts the Mille Pro MP 250 at Qtc 0.717, resonance 39.8 Hz, half power 39.3 Hz anechoic. One box serves Dual 2 Ohm and Dual 4 Ohm, so the depth is the one that keeps both closest to 0.707. One box serves every coil version: the Dual 2 Ohm at Qtc 0.717, the Dual 4 Ohm at Qtc 0.697.

Measure the base depth, not the top. This cabinet is 17.50 in deep where it meets the floor, 11.31 at the top, 40 wide and 17 tall. In an SUV the 40 has to clear between the rear wheel wells at floor height, the base depth is measured from the seat back with the seat upright and latched, and the 17 has to clear the cargo cover.

All three terminal cups are on the rear panel, and the rear panel is the face that goes against the seat back. Wire all three before the box goes in, with enough slack to slide it into place; once the raked face is against the seat you cannot reach them.

Impedance. MP 250 10" D2.3: wire for 3 ohms (coils in parallel, the three in series), the load most monoblocks are built to deliver full power into; 1.33 ohms is the other clean option (coils in series, the three cups in parallel). MP 250 10" D4.3: wire for 2.67 ohms (coils in series, the three cups in parallel), the load most monoblocks are built to deliver full power into; 6 ohms is the other clean option (coils in parallel, the three in series). Work the load out before you buy the amplifier, not after.

Power. Size the amplifier for the set, not one driver: 350 to 500 W RMS per driver is 1,050 to 1,500 W RMS across all 3. On this driver travel sets the top, not heat: Xmax arrives at 503 W per driver with a 25 Hz subsonic, under the 600 W rating. Set the 25 Hz subsonic to use the top of that range; without it keep each driver under 312 W.

Hertz's Qes and Qms reproduce the printed Qts within 3 percent, so the alignment rests on a self-consistent set. Hertz do not publish driver displacement; we deduct an estimated 0.069 per driver, so true net can sit a few hundredths either way.

Polyfill is in as a wall lining in every chamber. Do not add more: it makes the box act larger and walks Qtc off 0.72.

Before you order

Questions

Does this fit the Hertz Mille Pro MP 250, and its coil versions?

Yes. Each opening is cut to 9.291 in for the 10.551 in frame, and the 5.55 in deep motor clears the raked rear panel with 5.46 in to spare. Both coil versions share the frame, cutout and mounting depth; the alignment table lists each.

Run three matched drivers, same model and same coil, so every chamber sees the alignment on this page.

Why 1.159 cubic feet per driver, and what alignment does it target?

On Hertz's published Fs 30.0 Hz, Qts 0.540 and Vas 25.0 liters, 1.159 cubic feet per driver gives Qtc 0.717, system resonance 39.8 Hz and half power 39.3 Hz.

One box serves Dual 2 Ohm and Dual 4 Ohm, so the depth is the one that keeps both closest to 0.707.

What amplifier power should I run, and how should I wire it?

Hertz rates the Mille Pro MP 250 at 600 watts RMS per driver. Recommended amplifier: 350 to 500 W RMS per driver, 1,050 to 1,500 W RMS for the full set of 3. Travel, not heat, sets the top: the cone reaches Xmax at 503 W per driver with a 25 Hz subsonic set, under the 600 W rating. The top of that range needs the 25 Hz subsonic; without it keep each driver under 312 W.

Each MP 250 10" D2.3 has two 2 ohm voice coils, 4 ohms in series or 1 ohm in parallel. With each driver's coils in series and the three cups in parallel, the three present 1.33 ohms to a mono amplifier. With each driver's coils in parallel and the three in series, they present 3 ohms. Three drivers do not reach the round loads a pair does, so check the result against your amplifier's minimum stable impedance before powering up. Each MP 250 10" D4.3 has two 4 ohm voice coils, 8 ohms in series or 2 ohms in parallel. With each driver's coils in series and the three cups in parallel, the three present 2.67 ohms to a mono amplifier. With each driver's coils in parallel and the three in series, they present 6 ohms. Three drivers do not reach the round loads a pair does, so check the result against your amplifier's minimum stable impedance before powering up.

Will it fit my SUV?

It is 40 inches wide, 17 tall and 17.50 deep at the base, tapering to 11.31 at the top. Measure between the rear wheel wells, the floor depth with the seat upright, and the height under your cargo cover.

The raked face goes against the seat back and the woofers fire toward the liftgate.

Why are all three terminal cups on the back?

Each driver has its own sealed chamber, and the center chamber has no side wall to take a cup. Putting all three on the rear panel gives a matching set, one cup per chamber.

Wire them at the amplifier end; there is no cross-chamber wiring inside the cabinet.

What is the expected low-frequency extension?

Anechoic F3 is 39.3 Hz per driver with system resonance at 39.8 Hz.

Those figures exclude cabin gain. An SUV cabin adds real output below about 50 Hz, so in-vehicle response runs deeper than the numbers above.

Do I need to add polyfill or damping?

No. Polyfill is already installed as a light wall lining in every chamber, and the quantity is chosen so it does not change the acoustic volume.

Do not add more. Packing a sealed box makes it behave as though it were larger, which moves the alignment away from 1.159 cubic feet per driver.

Are the drivers included?

No. This is an enclosure only. You receive the cabinet finished in plush black carpet with the gloss black acrylic baffle insert, three pre-wired terminal cups on the rear panel, the polyfill lining in place, threaded inserts and stainless machine screws.

Bring three matched Hertz Mille Pro MP 250 drivers. The cabinet is cut direct fit to them, not a general purpose 10 inch box.

Same series, same size

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