Hertz MPS 300 Review: A 12-Inch Shallow Sub in S2 and S4 Versions
Updated: Oct 7
The Hertz MPS 300 is a 12-inch shallow subwoofer from Hertz's Mille Pro range, sold as the 2-ohm MPS 300 S2 or the 4-ohm MPS 300 S4. Both handle 500 W continuous and 1,000 W peak, need only 88 to 89 mm of mounting depth, and work in a sealed box of 22.7 litres. Our single listing covers both versions at an Indian MRP of ₹49,990, which is ₹10,000 more than the full-depth MP 300 and ₹10,000 less than Hertz's ready-loaded MPBX 300 S2 box. It is for custom installs where depth is the problem: a false boot floor, behind a seat, or anywhere a normal 12-inch sub won't go. See it on our Hertz MPS 300 S2/S4 product page.
Key points
A true 12-inch driver with 16.8 mm of Xmax, yet under 90 mm deep.
Two single-coil versions: S2 for 2-ohm-stable mono amplifiers, S4 for 4-ohm loads, including bridged four-channel amps.
Hertz publishes sealed and ported box designs, including an S2 sealed box only 115 mm deep.
Owner feedback on the bare driver is limited to two star ratings; the same driver in Hertz's MPBX box has a little more.
Hertz MPS 300 specifications
Specification | Hertz MPS 300 (S2 / S4) |
|---|---|
Size | 300 mm (12-inch), single voice coil |
Impedance | 2 Ω (S2) / 4 Ω (S4) |
Power handling | 500 W continuous / 1,000 W peak |
Sensitivity | 84.5 dB (S2) / 85 dB (S4) |
Frequency response | 25–400 Hz |
Voice coil | 38 mm (1.5 in), six-layer copper |
Magnet | Ferrite, 156 x 60 x 36 mm |
Xmax / Xmech | 16.8 mm / 20 mm |
Fs / Qts / Vas | S2: 24 Hz / 0.51 / 64.9 litres; S4: 23 Hz / 0.42 / 62.13 litres |
Mounting depth | 88–89 mm (Hertz documents vary) |
Mounting hole | 283 mm |
Weight | 6.64 kg |
Recommended sealed box | 22.7 litres |
Grille | Screw-less mesh, included |
India MRP | ₹49,990 (S2 or S4) |
Figures are from Hertz's MPS 300 S2 page, the S4 page and the S2 tech sheet. The S2 page gives 89 mm of mounting depth while the S2 tech sheet says 88 mm, so allow for the larger figure.
How Hertz made a 12-inch sub this shallow
A conventional 12-inch sub needs a deep basket to give its cone room to move. Hertz says the MPS gets around this with a dedicated support structure for the spider and coil that lets the magnet assembly move inward, and claims about 20% more cone excursion than traditional designs. The rear isn't vented, which Hertz says allows a shallower box, and its A.I.R. design, Hertz says, prevents air-compression-related limitations.
The rest is solid hardware: a six-layer 38 mm copper coil for heat capacity, a die-cast aluminium chassis, spring-loaded 8 AWG terminals and a screw-less mesh grille in the box. That grille matters in a car, where a shallow sub often sits exposed on a boot floor.
S2 or S4: matching the impedance to your amplifier
Choose the S2 if you have a mono amplifier that is stable at 2 ohms. Hertz's DP 1.500 makes 500 W RMS at 2 ohms, an exact match for the driver's continuous rating.
Choose the S4 for 4-ohm amplifiers. On the same DP 1.500 it gets 280 W RMS, so it will play less loudly. The S4 also suits a one-amplifier system: the DP 4.400 in three-channel mode is rated at 75 W x 2 for the front speakers plus 210 W bridged into a 4-ohm sub. Two S4s wired in parallel make a 2-ohm load, so a single DP 1.500 can drive a pair. Hertz lists the S4 at 85 dB and the S2 at 84.5 dB, a negligible difference; the amplifier matters more.
Box designs from Hertz
Hertz's sealed design for both versions is 22.7 litres in 16 mm wood. For the S2, it gives a compact 510 x 406 x 160 mm box or a flatter 770 x 406 x 115 mm performance version, with a 70–80 Hz low-pass and a 15 Hz subsonic filter. The S2 tech sheet describes the driver as optimised for very compact sealed boxes of 20 to 24 litres.
For more output at the bottom end, the S2's ported design is 26.9 litres tuned to 34 Hz, built 690 x 411 x 165 mm or 895 x 422 x 130 mm, with a 60–70 Hz low-pass and a 20 Hz subsonic filter. The S4 page lists its own figures, so check the right page for your version. If you'd rather not build a box at all, Hertz sells this driver ready-loaded as the MPBX 300 S2.
What owners and reviewers say about the Hertz MPS 300
When we checked in October 2026, we found no professional review of the MPS 300 and very little owner feedback.
UK retailer Four Car Audio shows one top-scale rating for the MPS 300 S2, from August 2025, and one for the MPS 300 S4, from December 2024. Neither has a written comment.
Two related sources add context. The same shop's page for the MPBX 300 S2, which is this S2 driver in Hertz's sealed box, has five ratings and short comments praising a big improvement in bass and sound quality. And the smaller 10-inch MPS 250 won EISA's In-Car Subwoofer award for 2022-2023, with the jury praising deep, fast bass from very small boxes. Neither assesses the MPS 300 itself. If you own one, please tell us how it performs.
MPS 300 vs MPBX 300 S2, MPS 250 and MP 300
The ready-made MPBX 300 S2 (₹59,990 MRP) uses the S2 driver in a braced, damped box 175 mm tall. It costs ₹10,000 more but saves building a box, and it is a 2-ohm load.
The 10-inch MPS 250 has the same ₹49,990 MRP and power rating. It is rated at 82.5 dB (S2) or 83.5 dB (S4) and needs only a 14.2-litre sealed box, so it is the one for even tighter spaces.
The full-depth MP 300 (₹39,990 MRP) is cheaper, handles 600 W and is rated at 86 dB, but needs 164 mm of mounting depth and a 28-litre sealed box. The Cento CS 300 (₹19,990 MRP) is a cheaper 12-inch option at 350 W continuous, with 130 to 147 mm of mounting depth, depending on the Hertz page, and a 32-litre box.
Who should buy it, and who shouldn't
Buy the MPS 300 if you are planning a custom enclosure in a shallow space, want 12-inch output from it, and can match the S2 or S4 to your amplifier.
Look elsewhere if depth isn't a problem, since the MP 300 or CS 300 costs less, or if you'd rather buy a finished box, in which case the MPBX 300 S2 is the same driver ready to install.
Installation notes for Indian cars
A shallow sub is only as good as its box. Build to Hertz's volume, use 16 mm wood as specified, and seal every joint, because a leaking sealed box loses bass. Measure the space with the box's outer dimensions, not the driver's, and leave room for the 283 mm cutout and the terminals. Secure the box properly for broken roads, keep the amplifier ventilated in summer heat, and use a fused power cable from the battery. Our sound damping guide helps stop panels rattling once the bass arrives. VA3 Car Studio in Ghaziabad offers professional installation of the complete system.
Price and where to buy
The Hertz MPS 300 has an MRP of ₹49,990 in our current Indian listing, which covers both the S2 and the S4; tell us which impedance you need when you order. Check today's price on the MPS 300 S2/S4 product page. Every driver we sell is a genuine Hertz product.
The bottom line
The MPS 300 solves a specific problem: real 12-inch bass in a space too shallow for a normal sub. Hertz backs it with detailed box designs and a choice of impedances. You pay a premium over the full-depth MP 300 and Cento CS 300, you need a well-built box and a suitable amplifier, and owner feedback is still thin.
Hertz MPS 300 FAQ
Should I buy the Hertz MPS 300 S2 or the S4?
Buy the S2 if your mono amplifier is stable at 2 ohms, such as the DP 1.500 with its 500 W RMS at 2 ohms. Buy the S4 for 4-ohm amplifiers, bridged four-channel amps, or to wire two subs to a 2-ohm load.
What size box does the MPS 300 need?
Hertz's sealed design is 22.7 litres for both versions, built in 16 mm wood. The S2 can also go in a 26.9-litre ported box tuned to 34 Hz, and for the S2 Hertz gives a compact and a flatter shape for each design.
How deep is the MPS 300?
Hertz lists a mounting depth of 88 to 89 mm, depending on the document, and a 283 mm mounting hole. Hertz's flattest sealed box design for the S2 is 115 mm deep overall.
Buy the Hertz MPS 300 S2/S4 Mille Pro in India
You can buy the Hertz MPS 300 S2/S4 Mille Pro online from VA3 Car Studio with pan-India shipping. See more Hertz subwoofers, compare other car subwoofers, or book subwoofer installation in Ghaziabad.
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