Hertz DCX 100.3 Review: A 4-Inch Dieci Coaxial for Dash and Small Door Openings
Updated: Oct 7
The Hertz DCX 100.3 is a 4-inch (100 mm) two-way coaxial speaker from the Dieci range, with a 15 mm neodymium PEI-dome tweeter in front of a water-repellent paper woofer. Hertz rates it at 30 W continuous (60 W peak) into 4 Ω, with 92 dB sensitivity and a 70 Hz to 21 kHz response. At ₹5,990 MRP, it is the least expensive Dieci coaxial we sell. It is made for the small openings many cars use on the dashboard, in rear doors or in rear side panels. See it on our Hertz DCX 100.3 product page.
Quick summary
A compact two-way for 4-inch openings: 15 mm PEI tweeter, TPU surround and a water-repellent cone.
92 dB sensitivity and 30 W continuous handling: a head-unit speaker first, an amplified one only with care.
Its 115 Hz resonance means it is a midrange-and-treble speaker, not a bass speaker.
Three UK buyer reviews with an average at the top of the scale; the only comment we could read calls it a real big improvement.
Hertz DCX 100.3 specifications
Specification | Hertz DCX 100.3 |
|---|---|
Type | 4-inch (100 mm) two-way coaxial |
Tweeter | 15 mm PEI dome, neodymium magnet |
Power handling | 30 W continuous, 60 W peak |
Impedance | 4 Ω (Re 3.3 Ω) |
Sensitivity | 92 dB |
Frequency response | 70 Hz – 21 kHz |
Woofer cone and surround | Water-repellent pressed paper; TPU |
Voice coil and magnet | 25 mm pure copper on Conex former; 70 x 32 x 10 mm |
Xmax | 1.5 mm |
Fs / Qts / Vas | 115 Hz / 0.79 / 1.7 litres |
Weight | 0.45 kg |
India MRP | ₹5,990 |
Figures come from Hertz's official DCX 100.3 page and match our listing. Dimensions are printed only as lettered figures (99, 94, 50 and 43 mm, plus 129 mm) without a legend, so compare them with your factory speaker rather than treating any one as the cutout.
What a small speaker in the dash should do
A 4-inch speaker on top of the dashboard fires up into the windscreen, and the glass reflects the sound back towards the cabin. Done well, that lifts vocals to eye level. Done badly, it sounds thin and harsh. The DCX 100.3 handles the part of the job a small driver can: Hertz specifies a large motor assembly for voice coil control, a TPU surround and a neodymium PEI-dome tweeter chosen for compactness and energy at high frequencies.
Its published resonance is 115 Hz and its excursion is 1.5 mm, so it is not a bass speaker, and it shouldn't be asked to be one. In a car with door woofers, let them carry the low end.
Head unit or amplifier?
With 92 dB sensitivity, the DCX 100.3 plays at a sensible level on head-unit power, and in most cars that is the right way to run it. Its 30 W continuous rating is modest. If you route it through an amplifier, keep the gain conservative and use a high-pass filter around 100 Hz or a little higher, so the cone isn't pushed beyond its 1.5 mm of travel. A 60 W-per-channel amplifier such as the Hertz DP 4.300 can feed it safely only with that kind of care.
One more check before replacing dash speakers: some factory systems split one channel between a dash speaker and a door speaker through a small inline filter. If yours does, the wiring needs thought, and a DSP can sort out the balance properly; our article on why DSP matters in car audio covers the basics.
What owners and reviewers say about the Hertz DCX 100.3
There is a little feedback, all positive. This is what we found when we checked in October 2026.
Four Car Audio, a UK Hertz dealer, counts three reviews, with an average at the top of its scale. A September 2016 buyer calls the speakers a real big improvement, and an October 2023 buyer gives a score one step below the top, with no comment. We could read only those two, and neither says which car or which position they went into, or what was replaced. The retailer's description, supplied by Hertz, is promotional.
DCX 100.3 vs JL C1-400x and DCX 87.3
The JL Audio C1-400x (₹12,490 MRP) is another 4-inch coaxial in our range. It uses a 19 mm aluminium-dome tweeter, is rated at 35 W RMS and quotes a response from 64 Hz. JL also publishes a 94 mm cutout and 46 mm mounting depth, which makes fitment easier to confirm. The DCX 100.3 costs ₹6,500 less and has a close continuous rating, so for a head-unit upgrade it is the sensible starting point.
Within Dieci, the smaller Hertz DCX 87.3 carries an MRP of ₹11,990, roughly twice the 4-inch model's price, with the same power rating and a response that starts higher. If your opening takes a 4-inch speaker, the DCX 100.3 is the obvious choice. For 5-inch openings, look at the DCX 130.3 (₹7,990 MRP).
Who should buy it, and who shouldn't
Buy the DCX 100.3 if your car has 4-inch dash, door or rear-panel openings with tired factory speakers, and you want clearer vocals on head-unit power without spending much.
Look elsewhere if you expect bass from a 4-inch speaker, or plan a high-powered system; a speaker with higher continuous handling, or a component set with a separate tweeter, suits that better.
Installation notes for Indian cars
Dash speakers usually sit under a grille held by clips, and the trim around them can be brittle after years of sun, so remove it gently. Measure the factory speaker, its screw holes and the depth available below the dash, or ask us to check fitment for your car; Hertz's lettered dimensions need comparing with the original. Foam tape around the frame stops buzzes against the dash plastic. In doors, keep the water barrier intact. VA3 Car Studio in Ghaziabad offers professional installation.
Price and where to buy
The Hertz DCX 100.3 has an India MRP of ₹5,990 for the pair. Check today's price on our DCX 100.3 product page. Every pair we sell is a genuine Hertz product, and we can check whether your dash openings take a 4-inch speaker before you order.
The bottom line
The DCX 100.3 is a modest, sensibly built 4-inch coaxial and the most affordable Dieci coaxial we sell. It suits dashboards and small doors on head-unit power, the few owners who have reviewed it rate it highly, and it costs far less than the alternatives above. Just don't ask it for bass or big amplifier power.
Hertz DCX 100.3 FAQ
Can the Hertz DCX 100.3 replace 4-inch dashboard speakers?
Often, yes, if the opening, screw holes and depth match. Hertz prints only lettered dimensions, so compare them with the factory speaker, and check whether the dash speaker shares a channel with the doors.
Does the DCX 100.3 need an amplifier?
No. Its 92 dB sensitivity suits head-unit power. If you use an amplifier, keep the gain conservative and add a high-pass filter around 100 Hz, because the continuous rating is 30 W.
Should I choose the DCX 100.3 or the DCX 87.3?
Choose by opening size. If your car takes a 4-inch speaker, the DCX 100.3 costs about half as much as the 87 mm DCX 87.3, with the same power rating and deeper rated bass (70 Hz against 130 Hz).
Buy the Hertz DCX 100.3 Dieci in India
You can buy the Hertz DCX 100.3 Dieci online from VA3 Car Studio with pan-India shipping. See more Hertz speakers, compare other coaxial speakers, or book a speaker upgrade in Ghaziabad.
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