Resolut M25-IN Review: MOST 25 Digital Input for Factory Car Audio Systems
Updated: Oct 6
The Resolut M25-IN is a plug-in module that lets a Resolut processor take its music straight from a car's factory MOST 25 optical network, receiving up to eight channels of digital audio and, Resolut says, passing them on in BitPerfect form. Its India MRP is ₹54,990, and Resolut lists it for the A-DSP, T-DSP mk2, H-DSP and M-DSP. It's only relevant to cars whose factory audio runs over a MOST 25 bus, a fibre-optic system used in the factory infotainment of some cars. Resolut doesn't publish a vehicle list, so we check each car first. See today's price on our M25-IN product page.
Quick summary
Receives up to eight channels of digital audio from a factory MOST 25 optical bus.
Resolut says the signal passes directly to the processor in BitPerfect mode, so there is no analogue step in between.
Draws no more than 200 µA with the system off and no more than 900 mW when running.
Resolut names no compatible vehicles, so fitment has to be checked car by car.
Resolut M25-IN specifications
Specification | Resolut M25-IN |
|---|---|
Type | Plug-in MOST 25 digital input module |
Interface | MOST, optical, 25 Mbit |
Channels received | Up to 8 |
Transfer | BitPerfect, per Resolut |
Current when off | No more than 200 µA |
Power when on | No more than 900 mW |
Dimensions | 42 x 34 x 24 mm |
Compatible processors | A-DSP, T-DSP mk2, H-DSP, M-DSP |
Vehicle list | Not published by Resolut |
India MRP | ₹54,990 |
Figures come from Resolut's M25-IN page. Our own listing names several car brands, but Resolut's page doesn't, so we haven't repeated them here.
What MOST 25 integration means
MOST stands for Media Oriented Systems Transport. In cars built around it, the factory head unit and amplifier exchange audio as digital data over optical fibre rather than as analogue signals on copper wires; Resolut's module works with the 25 Mbit version.
Normally, adding a processor to such a car means taking the factory amplifier's speaker-level outputs, after the factory's own processing and amplification, and converting them back to digital through an analogue input such as the A-IN. The M25-IN instead connects to the MOST bus itself, so the factory system's digital audio passes into the processor directly. Resolut describes that as BitPerfect transfer of up to eight channels, which avoids the extra conversion steps entirely.
What Resolut doesn't publish
Resolut's page is brief. It doesn't list compatible cars or head units, and it doesn't explain how factory volume control, warning chimes, navigation prompts or parking-sensor tones are handled once the processor takes over. Those details vary between factory systems, so treat the M25-IN as a project to plan with an installer rather than a part to order on spec alone.
Which processors it works with
Resolut lists the M25-IN for the A-DSP, T-DSPmk2, H-DSP and M-DSP; the X-series processor amplifiers don't list it. Resolut's T-DSP mk2 page lists a MOST 150 module and a brand-specific Ethernet module as in development (the page carries no date), and Resolut's DSP Tool manual lists MOST 150 among its optional interfaces, so the M25-IN is specifically for MOST 25 systems. If your car uses one of those newer networks, this module isn't the answer.
What owners and reviewers say about the Resolut M25-IN
We found no owner reviews of the M25-IN when we checked in October 2026. The Moscow dealer Magnitolkin's M25-IN page says there are no reviews yet and, like Resolut, names no car models; the SoundDrive Resolut listing shows no ratings; and Drive2, where Russian installers document factory integrations, blocked our access. Without real-world reports, we can't say how smoothly it works in any particular car. If you've fitted one, we'd like to hear which car it was.
M25-IN vs analogue integration
The alternative in a MOST car is analogue integration from the factory amplifier's outputs. On a Resolut processor that means the A-IN (₹44,990), which accepts speaker-level signals up to 45 V RMS. Outside Resolut, JL Audio's FiX 86 (₹69,990) is built for factory integration, with eight inputs accepting 250 mV to 30 V RMS and delay correction for summing factory signals, at 24-bit/48 kHz. Both work regardless of the car's network, at the cost of an analogue step.
The cheapest Resolut route to a MOST 25 digital connection is the A-DSP plus the M25-IN, at a combined MRP of ₹2,74,980. That's a serious outlay, so it's worth considering mainly if a digital feed from the factory system, which Resolut describes as BitPerfect, is the point of the build.
Who should buy it, and who shouldn't
Consider the M25-IN if your car's factory system uses a MOST 25 bus, you're keeping the factory head unit, and you want its audio to reach a Resolut A-DSP, T-DSPmk2, H-DSP or M-DSP digitally.
Skip it if your car doesn't use MOST 25, if you own an X-series processor amplifier, or if a well-executed analogue integration would satisfy you for less. Our guide on whether your car needs an amplifier can help frame the wider plan.
Installation notes for Indian cars
Ask us to identify your car's system before ordering; MOST connections use distinctive fibre-optic connectors that an installer can recognise. Fibre must never be bent tightly, crushed under trim or left with dirty connector faces, and factory networks can be sensitive to how new devices are added, so this is a job for someone experienced with them. The module's low standby draw, no more than 200 µA, matters if the car sits parked for long spells. Once connected, the processor still needs a full tune; our guide to setting up a DSP in your car explains what's involved. VA3 Car Studio in Ghaziabad offers professional installation.
Price and where to buy
The Resolut M25-IN has an MRP of ₹54,990. Check today's price on our M25-IN listing, and send us your car's make, model and year so we can check its audio system first.
The bottom line
The M25-IN does one specialised job: it takes up to eight channels of digital audio from a factory MOST 25 network into a Resolut processor without an analogue step. For the right car it keeps the factory signal digital all the way into the processor. But Resolut publishes no vehicle list and we found no owner reports, so confirm your car's system with us before you commit.
Resolut M25-IN FAQ
Will the Resolut M25-IN work in my car?
Only if your car's factory audio system uses a MOST 25 optical bus. Resolut doesn't publish a list of compatible vehicles, so send us your car's details and we'll check its system before you order.
How many channels can the M25-IN receive?
Up to eight, according to Resolut. Resolut's DSP Tool manual lets you route and mix inputs to each output, but it doesn't say how the MOST channels are mapped, so ask us.
Does the M25-IN drain the battery when the car is parked?
Resolut rates its current draw with the system off at no more than 200 µA, and its power consumption when running at no more than 900 mW.
Buy the Resolut M25-IN MOST 25 Digital Input Module in India
You can buy the Resolut M25-IN MOST 25 Digital Input Module online from VA3 Car Studio with pan-India shipping. See more Resolut DSP processors, compare other car DSP processors, or book DSP installation and tuning in Ghaziabad.
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