Hertz DS 30.3 Review: A 12-Inch Dieci Sub Designed for Compact Boxes
Updated: Oct 7
The Hertz DS 30.3 is a 12-inch (300 mm) subwoofer driver from Hertz's Dieci range, with a single 4 Ω voice coil, 250 W continuous and 1000 W peak power handling, and 91 dB sensitivity. Its Indian MRP is ₹9,990, the same as the Uno S 300 S4 and about half that of the Cento CS 300. What sets it apart is the box Hertz designed it around: a 21-litre sealed enclosure measuring 320 x 320 x 205 mm. It suits buyers who want 12-inch bass from one modest mono amplifier without filling the boot. See today's price on our Hertz DS 30.3 product page.
Quick summary
A 12-inch Dieci driver rated at 250 W continuous on a single 4 Ω coil, with 91 dB sensitivity.
Hertz's recommended boxes are compact: 21 litres sealed, or 23.9 litres reflex tuned to 40 Hz.
It needs a mono amplifier of roughly 200 to 300 W into 4 Ω, such as Hertz's DP 1.500.
Owner feedback is scarce: we found only two ratings, for the boxed DBX 30.3 that uses the DS sub.
Hertz DS 30.3 specifications
Specification | Hertz DS 30.3 |
|---|---|
Type | 12-inch (300 mm) subwoofer driver, single voice coil |
Impedance | 4 Ω (DC resistance 3.3 Ω) |
Power handling | 250 W continuous / 1000 W peak |
Sensitivity | 91 dB |
Frequency response | 28–300 Hz |
Cone and surround | Polypropylene with mica injection; butyl rubber |
Voice coil | 38 mm (1.5 in) copper on an aluminium former |
Fs / Qts / Vas | 32 Hz / 0.62 / 70 l |
Xmax / Xmech | 9 mm / 16 mm |
Mounting depth | 120 mm |
Weight | 4 kg |
Recommended sealed box | 21 l, Fb 56 Hz, 320 x 320 x 205 mm |
Recommended reflex box | 23.9 l, Fb 40 Hz, 340 x 320 x 220 mm |
India MRP | ₹9,990 |
Figures come from Hertz's official DS 30.3 page and tech sheet, and match our store listing. Hertz doesn't label a cutout diameter in the material we could read, so ask us to confirm it before you cut a baffle.
A 12-inch designed for small boxes
Hertz says the Dieci subs are designed for compact sealed or reflex enclosures, and the published 21-litre and 23.9-litre boxes bear that out. Sealed gives tighter bass and is easier to build. Reflex digs deeper and plays louder, but we couldn't find port dimensions on Hertz's page, so the port must be calculated for your build.
The cone is polypropylene stiffened with mica, a material that doesn't soak up moisture the way untreated paper can, on a butyl rubber surround. Hertz also describes a venting system for better heat dissipation, useful in a boot that bakes through May and June. Linear excursion is 9 mm, less than the CS 300's 12.5 mm, so the DS 30.3 is better suited to clean daily-driver bass than to chasing maximum output.
Choosing an amplifier on a sensible budget
As a passive driver, the DS 30.3 can't run from a head unit; it needs a mono amplifier, and with one 4 Ω coil, 200 to 300 W into 4 Ω is the right size. Hertz's own DP 1.500 is the natural partner: Hertz rates it at 280 W at 4 Ω (1% THD, 14.4 V), and its speaker-level input accepts 1.6 to 40 V RMS, handy if you keep a factory touchscreen without RCA outputs. It also suits a pair, since two DS 30.3s in parallel present about 2 Ω, where the DP 1.500 is rated at 500 W, roughly 250 W per sub.
On a tighter budget, the Class AB Zapco ST-1B (₹15,990 MRP) is rated at 200 W into 4 Ω. Zapco lists RCA inputs only, so a factory head unit would need a line-output converter such as the JL Audio LoC22. Hertz measures the DP 1.500's ratings at 14.4 V; at idle with the AC on, voltage can sit lower, and so does any amplifier's output. Set the gain with a test tone, low-pass around 80 Hz, and use the subsonic filter in a ported box. Our guide on whether you need an amplifier covers the basics.
What owners and reviewers say about the Hertz DS 30.3
When we checked in October 2026, readable owner feedback on the DS 30.3 was almost non-existent. Sonic Electronix in the US and Solocaraudio in Spain list the driver, but neither page had a customer review. Sonic Electronix's spec table also calls it dual 4-ohm; Hertz specifies a single 4 Ω coil, so wire it by Hertz's figures.
The nearest thing to owner feedback is on UK retailer Four Car Audio's DBX 30.3 page. The DBX 30.3 is Hertz's ready-made sealed 12-inch box, and Hertz says it uses the DS sub, so this is related feedback, not a review of the bare driver. Its two ratings are both at the top of the site's seven-point scale: a June 2024 buyer left a one-line comment calling it superb and mentioning the sound quality, and a June 2026 rating has no comment. That's far too little for a consensus.
Hertz's own claims of high efficiency and efficient cooling are promotional, not an independent test. If you own a DS 30.3, tell us how it has held up.
DS 30.3 vs S 300 S4, DS 25.3 and CS 300
At the same ₹9,990 MRP, the Uno Hertz S 300 S4 shares the 12-inch size, 4 Ω coil and 250 W continuous rating, but it differs in cone material and box size. It uses a pressed-paper V-cone with a foam surround and 89.5 dB sensitivity, and Hertz's recommended boxes for it are roughly twice the volume: 42 litres sealed or 50 litres reflex. If boot space is tight, the DS 30.3 is the easier fit, and it's 1.5 dB more sensitive.
The 10-inch DS 25.3, also ₹9,990 MRP, handles 150 W continuous at 89 dB and wants just 15.3 litres sealed, so pick it if space or amplifier power is limited. To skip box building, the DBX 25.3 puts a 10-inch DS driver in a ready-made sealed enclosure (₹19,990 MRP). A step up, the Cento CS 300 (₹19,990 MRP) handles 350 W continuous, but at 86.5 dB it needs noticeably more power for the same loudness, and Hertz recommends a 32-litre sealed box for it.
Who should buy it, and who shouldn't
Buy the DS 30.3 if you want a 12-inch sub in a small box, driven by one 200 to 300 W mono amplifier, to fill out a factory or entry-level front stage in a hatchback or compact sedan.
Look elsewhere if you want competition-level output, or you have no plan for an amplifier and a box. For something you simply plug in, the DBA 201 active box pairs an 8-inch driver with a built-in 220 W amplifier.
Installation notes for Indian cars
Build the box from MDF, seal every joint, and stay close to Hertz's volumes. If you reshape the sealed box to suit your boot, keep it near 21 litres with internal depth comfortably more than the 120 mm mounting depth. Strap or bracket the box down so it can't slide over speed breakers and broken roads.
Mount the amplifier where air can reach it, not under the boot carpet, and fuse the power cable near the battery, to the rating in the amplifier's instructions. A 12-inch also wakes up boot-lid rattles; our sound damping guide helps. VA3 Car Studio in Ghaziabad offers professional installation.
Price and where to buy
The Hertz DS 30.3 carries an MRP of ₹9,990. VA3 Car Studio often sells below MRP, so check the current offer on the DS 30.3 product page. The box contains the subwoofer only; Hertz's DSG 300.3 grille is sold separately.
The bottom line
The DS 30.3 offers 12-inch bass from a 21-litre box, 91 dB sensitivity that a modest amplifier can drive, and a ₹9,990 MRP. It isn't built for extreme output, and owner feedback is almost absent, so buy it on Hertz's published figures. With a 200 to 300 W amplifier and a well-built box, it adds proper low end without taking over the boot.
Hertz DS 30.3 FAQ
What size box does the Hertz DS 30.3 need?
Hertz recommends a compact sealed box of 21 litres, about 320 x 320 x 205 mm, or a 23.9-litre reflex box tuned to 40 Hz. Sealed is smaller and tighter; reflex adds deeper bass for a little more space.
Can I run the DS 30.3 from my head unit?
No. It is a passive driver, so it needs a mono amplifier. One delivering roughly 200 to 300 W into 4 Ω suits a single DS 30.3; Hertz rates its DP 1.500 at 280 W at 4 Ω.
Is the DS 30.3 a single or dual voice coil subwoofer?
Hertz lists a single 4 Ω voice coil with 3.3 Ω DC resistance. One sub is a 4 Ω load, and two wired in parallel make about 2 Ω, which suits mono amplifiers that are stable at 2 Ω.
Buy the Hertz DS 30.3 Dieci in India
Check the Hertz DS 30.3 Dieci price in India, browse more Hertz subwoofers or compare all car subwoofers in India. Want it fitted properly? Book subwoofer installation at our Ghaziabad studio.
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