Performance Optimized · Datasheet
Performance Optimized Wedge Wide Sealed Triple 12" Enclosure Hertz Mille Pro MP 300 · Triple 12" Sealed enclosure
- Net volume
- 1.915 cu ft per driver, 5.74 cu ft total, after both dividers and an estimated 0.109 cu ft displacement per driver
- Max mounting depth
- 6.46 in required; 10.05 in clearance above the motor against the raked rear panel
- External dimensions
- 44 in W × 17 in at the seat face H × 23.00 in at the base D
- Front baffle
- 1.5 in double baffle, outer layer machined as a flush recess
- Best For: Triple Hertz Mille Pro MP 300 SUV Cargo-Floor Builds
- Net Volume: 1.915 cu ft per Driver (5.74 cu ft Net Total)
- Driver Match: Three Hertz Mille Pro MP 300 (Dual 2 Ohm / Dual 4 Ohm), matched
- Construction: 3 Chambers | 44" Wide Wedge | V-Groove/Dado | Double 1.5" Baffle | 3 Terminal Cups
Spec of record
Technical specifications
| Specification | Value |
|---|---|
| Series | Proline X Performance Optimized Wedge Wide |
| Compatible Driver | Hertz Mille Pro MP 300, quantity 3, matched. Direct fit |
| Configuration | Triple 12 inch sealed wedge, 3 chambers, 1 driver per chamber |
| Mounting Position | SUV cargo floor, raked face against the rear seat back |
| Firing Direction | Rearward toward the liftgate. Not a down fire design |
| External Width | 44 in |
| External Height | 17 in at the seat face |
| External Depth | 23.00 in at the base, tapering to 16.81 in at the top |
| Internal Volume, Gross | 6.29 cu ft total |
| Internal Volume, Net Acoustic | 1.915 cu ft per driver, 5.74 cu ft total, after both dividers and an estimated 0.109 cu ft displacement per driver |
| Driver Mounting Depth | 6.46 in required; 10.05 in clearance above the motor against the raked rear panel |
| Alignment Per Driver | MP 300 12" D2.3 Qtc 0.777, fc 37.2 Hz, F3 34.2 Hz; MP 300 12" D4.3 Qtc 0.646, fc 36.9 Hz, F3 40.7 Hz anechoic |
| Woofer Openings | 3 at 11.299 in |
| Woofer Layout | One row across the face |
| Frame Outer Diameter | 12.638 in |
| Fs / Qts / Qes / Qms | 23.0 Hz / 0.480 / 0.530 / 5.900 |
| Vas / Sd / Xmax | 88.0 L / 531 cm2 / 16 mm |
| Driver Power Handling | 600 W RMS per driver, 1800 W RMS for the set of 3 (thermal rating) |
| Recommended Amplifier | 320-450 W RMS per driver, 960-1,350 W RMS for the full set |
| Parameter Source | Hertz published specifications |
| Material | Langboard Elite MDF |
| Construction | CNC cut, V-groove and dado joinery |
| Panel Thickness | 0.75 in |
| Front Baffle | 1.5 in double baffle, outer layer machined as a flush recess |
| Internal Bracing | Two full-height 3/4 in dividers |
| Driver Mounting | Threaded inserts, stainless machine screws included |
| Terminal Cups | Three Proline X ABS and carbon fiber composite, on the rear panel, one per chamber, pre wired 12 gauge OFC |
| Acrylic Insert | Gloss black acrylic baffle insert standard |
| Damping | Light polyfill wall lining in every chamber, does not alter acoustic volume |
| Carpet | Plush black |
| Shipping Weight | 99 lb |
| Warranty | 1 Year Limited |
| Built In | Tullahoma, Tennessee |
Modelled response
Performance in this enclosure
00Sizing the amplifier
Every wattage on this panel is per driver. This cabinet holds three, so the amplifier feeds all three at once.
01Is it a sealed driver?
Efficiency bandwidth product places the motor before anything else is decided.
02What the box does to it
1.915 cu ft against a 88.0 L Vas.
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 16.0 mm — and a bigger one once a subsonic filter stops it wasting travel below the passband.
| Param | Value | Unit | Note |
|---|---|---|---|
| Fs | 23.00 / 24.00 | Hz | free-air resonance |
| Qts | 0.480 / 0.420 | Dual 2 Ohm / Dual 4 Ohm | |
| Vas | 88.00 / 74.00 | L | equivalent compliance |
| Sd | 530.7 | cm² | effective piston area |
| Xmax | 16 | mm | one-way linear travel |
| Pe | 600 | W | continuous RMS |
| SPL | 84.9 | dB | 1 W / 1 m, derived from T/S |
Driver parameters as published by Hertz MP 300 12" D2.3 / MP 300 12" D4.3 published specifications. Curves computed against this enclosure’s actual net airspace.
From the shop floor
Installer's take
Start with the size. 1.915 cubic feet per driver puts the Mille Pro MP 300 at Qtc 0.777, resonance 37.2 Hz, half power 34.2 Hz anechoic. Maximally flat on these figures would need 2.66 cubic feet per driver. The wide platform stops at 23 inches deep, so this box lands a little above flat: a small lift near resonance and firm midbass. One box serves every coil version: the Dual 2 Ohm at Qtc 0.777, the Dual 4 Ohm at Qtc 0.646.
Measure the base depth, not the top. This cabinet is 23.00 in deep where it meets the floor, 16.81 at the top, 44 wide and 17 tall. In an SUV the 44 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 300 12" 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 300 12" 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: 320 to 450 W RMS per driver is 960 to 1,350 W RMS across all 3. On this driver travel sets the top, not heat: Xmax arrives at 451 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 303 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 0.109 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 0.78.
Before you order
Questions
Does this fit the Hertz Mille Pro MP 300, and its coil versions?
Yes. Each opening is cut to 11.299 in for the 12.638 in frame, and the 6.46 in deep motor clears the raked rear panel with 10.05 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 1.915 cubic feet per driver, and what alignment does it target?
On Hertz's published Fs 23.0 Hz, Qts 0.480 and Vas 88.0 liters, 1.915 cubic feet per driver gives Qtc 0.777, system resonance 37.2 Hz and half power 34.2 Hz.
Maximally flat on these figures would need 2.66 cubic feet per driver. The wide platform stops at 23 inches deep, so this box lands a little above flat: a small lift near resonance and firm midbass.
What amplifier power should I run, and how should I wire it?
Hertz rates the Mille Pro MP 300 at 600 watts RMS per driver. Recommended amplifier: 320 to 450 W RMS per driver, 960 to 1,350 W RMS for the full set of 3. Travel, not heat, sets the top: the cone reaches Xmax at 451 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 303 W.
Each MP 300 12" 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 300 12" 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 44 inches wide, 17 tall and 23.00 deep at the base, tapering to 16.81 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 34.2 Hz per driver with system resonance at 37.2 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 1.915 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 300 drivers. The cabinet is cut direct fit to them, not a general purpose 12 inch box.
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