Hertz MPS 300 S4 12-inch Peak 1000W Shallow Car Subwoofer

Getting deep, powerful bass in a car with limited boot space used to mean making compromises. The Hertz MPS 300 S4 changes that. At just 88mm deep, this 12-inch subwoofer from the Mille Pro series fits where standard subs simply can't, without giving up the output or low-frequency extension you'd expect from a full-size driver. If space is tight but your standards aren't, this is the sub to look at.

What is the Hertz MPS 300 S4?

The MPS 300 S4 is a 12-inch shallow-mount subwoofer from Hertz's Mille Pro series. It's built specifically for installations where depth is the limiting factor — think under-bench enclosures in pickup trucks, shallow boot builds in sedans, or any setup where a standard sub just won't fit. It handles 500W continuously and peaks at 1000W, runs at 4 Ohm with a single voice coil, and is optimised to perform in ultra-compact sealed boxes starting from just 22.7 litres (0.8 cubic feet). The driver uses Hertz's A.I.R. technology and a non-vented rear design to maintain performance in tight enclosures.

Why Choose the Hertz MPS 300 S4?

• ✅ Ultra-shallow 88mm depth — fits where standard 12-inch subs cannot
• ✅ 1000W peak power from a driver that's barely 3.5 inches deep
• ✅ Optimised for compact sealed boxes from 22.7L — no large enclosure needed
• ✅ A.I.R. technology prevents thermal compression during high-power use
• ✅ 20% more mechanical excursion than traditional shallow designs
• ✅ Non-vented rear design allows even shallower enclosure builds
• ✅ Six-layer copper voice coil for high thermal capacity and long-term reliability
• ✅ Die-cast aluminum frame for rigidity under high-excursion loads
• ✅ Solid 8AWG spring-loaded terminals for a secure, rattle-free connection
• ✅ Screw-less mesh grille included for a clean, finished look

Key Features

• Size – 300mm (12 inches): Full 12-inch cone area for genuine low-frequency extension, despite the shallow profile.
• Power Handling – 500W Continuous / 1000W Peak: Handles serious amplifier output without distortion or thermal failure.
• Impedance – 4 Ohm, Single Voice Coil: Standard 4 Ohm load works with virtually any mono amplifier on the market.
• Depth – 88mm (3.46 inches): One of the shallowest 12-inch subwoofers available, enabling installs that would otherwise be impossible.
• Optimised Enclosure Volume – 22.7L to 24L (0.8 CF): Works in genuinely small sealed boxes, making it ideal for pickup truck under-bench builds and compact boot installs.
• Voice Coil – 38mm (1.5 in.) Six-Layer Copper: High thermal mass keeps the coil cool during extended high-power sessions.
• Xmech – 20mm (0.79 in.): 20% greater mechanical excursion than conventional shallow designs, delivering deeper bass from a smaller package.
• Non-Vented Rear Design: Eliminates the need for rear ventilation clearance, allowing the enclosure to be built even shallower.
• 8AWG Spring-Loaded Terminals: Horizontal solid terminals accept thick gauge wire and hold it securely without loosening over time.
• Screw-less Mesh Grille: Included with black screws for a clean, professional finish.
• Die-Cast Aluminum Frame: Rigid basket construction resists flex at high excursion levels.
• Frequency Response – 25Hz to 400Hz: Full bass range coverage from deep sub-bass to upper bass.
• Magnet – High Density Flux Ferrite: Powerful magnetic motor in a compact form factor.
• Cone – Polypropylene: Lightweight and stiff for accurate, responsive bass reproduction.

Advanced Technologies

A.I.R. – Air Intercooling Revolution: When a subwoofer works hard in a sealed enclosure, air compression inside the box creates heat that builds up in the voice coil and degrades performance over time. Hertz's A.I.R. technology addresses this directly by managing the thermal environment around the voice coil, preventing the compression-related limitations that cause shallow subs to run out of steam at high volumes. The result is consistent output even during extended, demanding listening sessions.

Dedicated Suspension Support Structure: The MPS 300 S4 achieves its shallow depth through a purpose-engineered suspension design. Hertz redesigned the spider and coil support structure to allow the magnetic group to move inward, reducing overall depth while simultaneously increasing the linear excursion range. This is why the MPS 300 S4 achieves 20% more cone travel than a conventional shallow-mount design — it's not a compromise, it's a re-engineered approach to the same problem.

Non-Vented Rear Design: Most subwoofers require clearance behind the magnet for ventilation. The MPS 300 S4's non-vented rear eliminates this requirement, meaning the enclosure can be built right up to the back of the driver. This is particularly valuable in pickup truck under-bench builds and other tight installations where every millimetre of depth matters.

EID – Scan, Discover, Identify: Hertz's EID system lets you scan the product to verify authenticity, access full specifications, and confirm compatibility. It's a quick way to check you have a genuine Hertz product and to pull up installation documentation on the spot.

Benefits

• 🔊 Deep, accurate 12-inch bass from a driver that's barely 3.5 inches deep
• 📦 Fits in enclosures as small as 22.7 litres — no large box required
• 🌡️ A.I.R. technology keeps performance consistent at high volumes
• ⚡ 4 Ohm single voice coil works with any standard mono amplifier
• 🔧 Non-vented rear means shallower enclosure builds are possible
• 🛡️ Die-cast aluminum frame handles high-excursion loads without flex
• 🔌 8AWG spring-loaded terminals make wiring clean and secure
• ✨ Mesh grille included for a finished, professional install appearance

Who Should Buy the Hertz MPS 300 S4?

• Pickup truck owners who want under-bench bass without a large enclosure
• Sedan and hatchback owners with shallow boot builds
• Car audio enthusiasts who want genuine 12-inch performance in a tight space
• Installers building compact sealed enclosures in the 22–24 litre range
• Anyone running a standard mono amplifier at 4 Ohm looking for a matched shallow sub
• Buyers who want Hertz Mille Pro quality without compromising on available space

Technical Specifications

Why Choose Dolphin Accessories?

• ✅ 100% Genuine Products – Every product is sourced directly from authorised distributors. No counterfeits, no grey imports.
• ✅ Expert Guidance – Our team knows car audio. We'll help you match the right amplifier, enclosure, and wiring for your specific vehicle and setup.
• ✅ Pan-India Delivery – We ship to every corner of India with careful, secure packaging so your gear arrives in perfect condition.
• ✅ Secure Packaging – Premium products get premium protection. Every order is packed to handle the journey.
• ✅ After-Sales Support – Questions after your purchase? We're here for installation tips, compatibility queries, and troubleshooting.
• ✅ Trusted by Enthusiasts – Thousands of car audio lovers across India rely on Dolphin Accessories for their upgrades.

Frequently Asked Questions

Q: What makes the Hertz MPS 300 S4 a shallow-mount subwoofer?
A: Its overall depth is just 88mm (3.46 inches), which is significantly shallower than a standard 12-inch subwoofer. This is achieved through a redesigned suspension structure that moves the magnetic group inward, reducing depth without sacrificing excursion.

Q: What enclosure size does the MPS 300 S4 need?
A: It's optimised for ultra-compact sealed enclosures starting from 22.7 litres (0.8 cubic feet). This makes it ideal for under-bench builds in pickup trucks and shallow boot installs in sedans.

Q: What amplifier power does the MPS 300 S4 need?
A: It handles 500W continuously at 4 Ohm. An amplifier rated between 300W and 500W RMS at 4 Ohm will drive it cleanly and reliably.

Q: Is the MPS 300 S4 compatible with standard mono amplifiers?
A: Yes. The 4 Ohm single voice coil is the most common impedance for mono subwoofer amplifiers, so it will work with virtually any standard mono amp.

Q: What is A.I.R. technology on the Hertz MPS 300 S4?
A: A.I.R. stands for Air Intercooling Revolution. It's a thermal management system that prevents heat buildup caused by air compression in sealed enclosures during high-power use, keeping the driver performing consistently at volume.

Q: Can I install the MPS 300 S4 in a pickup truck under-bench enclosure?
A: Yes, that's one of the primary use cases Hertz designed this subwoofer for. The shallow depth and small enclosure requirement make it well-suited to under-bench builds where height and depth are both limited.

Q: What does the non-vented rear design mean?
A: It means the back of the driver doesn't require ventilation clearance. This allows the enclosure to be built right up to the rear of the magnet, enabling shallower overall box dimensions.

Q: How does the MPS 300 S4 achieve 20% more excursion than traditional shallow designs?
A: Hertz redesigned the spider and coil support structure with a dedicated support frame that allows greater linear cone travel within the same shallow depth. This is what gives the MPS 300 S4 its depth-to-performance advantage.

Q: What terminals does the MPS 300 S4 use?
A: It uses solid horizontal 8AWG spring-loaded terminals. These accept thick gauge wire and hold it securely, making for a clean, rattle-free connection.

Q: Does the Hertz MPS 300 S4 come with a grille?
A: Yes, a screw-less mesh grille is included along with black screws, giving the installation a clean, finished appearance.

Q: What is EID on Hertz products?
A: EID stands for Scan, Discover, Identify. It's Hertz's product authentication system — scan the EID code to verify the product is genuine and access its full specifications and documentation.

Q: Where can I buy the Hertz MPS 300 S4 in India?
A: You can buy it right here at Dolphin Accessories. We offer 100% genuine Hertz products with pan-India delivery, secure packaging, and dedicated after-sales support.