Zapco REF 250.2 Review: 800 W Bridged Class AB Power for Sound-Quality Bass

Oct 2

7 min read

Updated: Oct 6

The Zapco REF 250.2 is the two-channel model in Zapco's Reference line and the most powerful per channel of its multichannel models: 2 x 250 W RMS into 4 Ω, 2 x 350 W into 2 Ω, or 800 W from one bridged channel into 4 Ω, all Class AB with rated distortion below 0.02%. Its Indian MRP is ₹1,59,990, ₹10,000 above the REF 500.1 monoblock and ₹30,000 below the four-channel REF 150.4. With no crossovers or bass controls, it suits a DSP-based system that needs clean, high power for subwoofers. Our REF 250.2 store page has today's price.

Zapco REF 250.2 two-channel Class AB amplifier from the Reference series

Summary

Two Class AB channels at 250 W (4 Ω) or 350 W (2 Ω), or one bridged channel at 800 W into 4 Ω.
The highest rated signal-to-noise ratio in the Reference line, above 104 dB.
Bridged, it makes far more power into 4 Ω than the REF 500.1 (800 W against 320 W); the monoblock keeps a 2 Ω rating.
No review of this exact model; a June 2026 test of two siblings found both beat their ratings.

Zapco REF 250.2 specifications

Specification	Zapco REF 250.2
Type	2-channel Class AB high-end amplifier
Power, 4 Ω	2 x 250 W RMS
Power, 2 Ω	2 x 350 W RMS
Power, 4 Ω bridged	1 x 800 W RMS
Rating conditions	14.4 V, 1% THD
THD at rated power	Less than 0.02%
Signal-to-noise ratio	More than 104 dB
Frequency response	10 Hz – 40 kHz (±1 dB)
Input sensitivity	0.5 – 8 V
Input impedance	More than 20 kΩ
Inputs	2 x RCA, balanced (internal switch for unbalanced)
Controls	Gain only
Fuse rating	2 x 40 A
Dimensions	416 x 210 x 62 mm
India MRP	₹1,59,990

Figures are from Zapco's REF 250.2 page, the REF owner's manual and the 2026 Indian catalogue, which agree on power and noise. Only one bridged load is rated, 4 Ω, so we treat it as the minimum for bridged use.

The strongest channels among the multichannel Reference models

Per channel, the REF 250.2 has two-thirds more power at 4 Ω than the REF 150.4 or REF 150.6 (250 W against 150 W); only the REF 500.1 monoblock has a stronger single channel (320 W at 4 Ω, 550 W at 2 Ω). The REF 250.2's signal-to-noise rating of above 104 dB is the best of the four Reference models.

The parts follow the rest of the series: Sanken MN1526 and MP1526 output transistors (rated by Zapco at 260 V and 15 A), hand-wound toroidal transformers, ELNA and Revenbi signal-path capacitors and socketed MUSES8820 op-amps. Zapco pitches the line at daily-use cars where two amplifiers are usually the most that fit; in that system, the REF 250.2 is a natural second amplifier, powering the bass while a four- or six-channel model runs the speakers.

Bridged or stereo: driving subwoofers

With even JL's flagship C7-650cw woofer recommended for 50–175 W, 250 W per channel is more than most door speakers need, so this amplifier's natural job is subwoofers.

Bridged, the two channels become one 800 W channel for a 4 Ω load. That is more than any single 4 Ω JL driver in the 2026 catalogue is rated for: the thin-line 13TW5v2-4 handles 600 W and the 12W3v3-4 500 W. Set the gain or a DSP limit to the sub's rating and the spare power simply keeps the amplifier clear of clipping. Don't bridge it into a 2 Ω or 3 Ω load, because Zapco gives no rating there.

In stereo, each channel can drive its own subwoofer. A dual-4 Ω sub with its coils in parallel presents 2 Ω, where the REF 250.2 makes 350 W per channel, a close match for two of JL's 400 W shallow-mount 12TW3-D4 or 10TW3-D4 subs. A pair of 4 Ω 12W3v3-4s would get 250 W each, well inside their rating.

There is no low-pass filter, subsonic filter or bass boost on board, so a DSP or a head unit's subwoofer crossover must supply them, including a subsonic high-pass for a ported box.

Building a two-amp Reference system

Pair a Zapco REF 150.4 running an active two-way front stage with a REF 250.2 on the subwoofer, and the two amplifiers total ₹3,49,980 at MRP. The same front amp with a Zapco REF 500.1 costs ₹3,39,980. The extra ₹10,000 buys much more power into a 4 Ω sub and a second channel for another subwoofer later; the REF 500.1 is the better match for one sub wired to 2 Ω, where it is rated at 550 W.

A processor with six or more outputs covers the system; Zapco's DSP-Z8 IV AT has eight, plus speaker-level inputs for factory touchscreens. Our article on the need for DSP in car audio systems explains why the processor matters so much here.

What owners and reviewers say about the Zapco REF 250.2

When we checked in October 2026, we found no owner or press review of the REF 250.2 itself. The closest evidence is a Russian-language CarMus bench and listening test from 22 June 2026 of two siblings in the same series, the four-channel REF 150.4 and the REF 500.1 monoblock. It doesn't cover the two-channel, and it shows no byline or score.

Both tested amplifiers delivered more than their rated power, with distortion in the thousandths of a percent; our REF 150.4 and REF 500.1 reviews give the figures. The testers described the REF 150.4's sound as light and airy at the top, neutral in the midrange and tight in the bass, and valued the socketed op-amps as a way to tune it.

Their reservations were a large chassis that doesn't suit installs with little space, and very detailed treble that can turn slightly dry with bright tweeters, which matters only if this amplifier ends up on a front stage. How the REF 250.2 itself measures and sounds is untested; if you own one, please tell us about it.

REF 250.2 vs REF 500.1 and Z-150.2 AP

Against the REF 500.1 (₹1,49,990), the load decides: 800 W bridged into 4 Ω against the monoblock's 320 W, while a single 2 Ω sub suits the REF 500.1 better (550 W, against 350 W from one REF 250.2 channel). The REF 250.2 also quotes a slightly better signal-to-noise ratio, above 104 dB against 102 or 103 dB, depending on the Zapco document.

The Zapco Z-150.2 AP (₹1,10,990) costs ₹49,000 less and is smaller at 328 x 190 mm. It is rated at 2 x 150 W into 4 Ω, 2 x 275 W into 2 Ω and 550 W bridged into 4 Ω, adds 1 Ω and 2 Ω bridged ratings for music signal only, quotes a higher signal-to-noise ratio (above 110 dB) and has pass-through RCA outputs, which no REF document lists. The REF answers with more power at 4 Ω and 2 Ω, lower rated distortion (below 0.02% against below 0.1%) and response to 40 kHz rather than 30 kHz.

Who should choose it, and who shouldn't

Choose it if you want clean Class AB power for one 4 Ω subwoofer, or for two dual-coil subs at 350 W each, in a DSP-based system, ideally alongside a REF 150.4 or REF 150.6.

Look elsewhere if your single sub is a 2 Ω load (the REF 500.1 suits it better), you need onboard bass controls, or bass per rupee matters more than amplifier class. Zapco's Class D ST-1000XM III is rated at 500 W into 4 Ω and 1,000 W into 1 Ω at ₹49,990 MRP.

Installation notes for Indian cars

At 416 x 210 x 62 mm, the REF 250.2 needs a proper mounting board rather than an under-seat slot in many cars. Next to a REF 150.4 or REF 500.1, the pair takes a space about 420 mm wide and 416 mm deep, plus room for cables and air; the back of the rear seat or a raised boot floor is where to start measuring.

Zapco specifies two 40 A fuses, 80 A in total. That is a protection rating, not a measured current draw, but it is a sensible figure to size the wiring around for this amplifier alone. With a second Reference amp, run one 0 AWG power cable from the battery to a fused distribution block, then individually fused 4 AWG leads to each amplifier; our Tchernov 4 AWG power cable review covers one option. Class AB amps idle warm and Indian summers start them hot, so keep the fins in open air, and set the internal unbalanced-input switch before mounting if your processor needs it. VA3 Car Studio in Ghaziabad installs and tunes two-amp Reference systems.

Price and where to buy

The REF 250.2 has an MRP of ₹1,59,990 in the 2026 Indian catalogue, and VA3 Car Studio often sells it for less; current pricing is on our Zapco REF 250.2 product page. It is a genuine Zapco amplifier, supplied through the brand's Indian distributor, Supreme Audiotek Pvt. Ltd., New Delhi.

Check today's price at VA3 Car Studio

Our verdict

The REF 250.2 is the Reference line's power amplifier: the most watts per channel of the multichannel models, the best rated noise figure in the series and 800 W bridged. It needs a DSP for every filter, has no test of its own, and Class D offers far more bass per rupee. As the bass half of a two-amp Reference system with a 4 Ω subwoofer, it is the strongest choice in the line.

Zapco REF 250.2 FAQ

Can the Zapco REF 250.2 power a subwoofer?

Yes. Bridged, it delivers 800 W into a single 4 Ω subwoofer, and in stereo it gives two subwoofers 250 W each at 4 Ω or 350 W each at 2 Ω. It has no low-pass filter, so a DSP or head-unit crossover must handle the filtering.

Should I choose the REF 250.2 or the REF 500.1 for one subwoofer?

For a 4 Ω sub, the REF 250.2 bridged is rated at 800 W against the REF 500.1's 320 W, for ₹10,000 more at MRP. For a dual-coil sub wired to 2 Ω, the REF 500.1's 550 W rating makes it the better fit, because Zapco rates the REF 250.2's bridged mode only at 4 Ω.

Is the REF 250.2 a good amplifier for door speakers?

It can drive them, but 250 W per channel is more than most door speakers need: even JL's C7-650cw woofer is recommended for 50–175 W. It makes more sense on subwoofers, with a REF 150.4 or REF 150.6 running the speakers.

Buy the Zapco REF 250.2 in India

Check the Zapco REF 250.2 price in India, browse more Zapco amplifiers or compare all car amplifiers in India. Want it fitted properly? Book amplifier installation at our Ghaziabad studio.