Keep Your Factory Harman Kardon Amp: Subaru Aftermarket Head Unit Install Kit (Maestro RR or RR2)

Item Number: AHH-HK-KIT

No sound after installing your new head unit? Harman Kardon-equipped Subaru vehicles use a separate factory amplifier (under the front passenger seat) that powers every speaker in the car. On the 2015-and-newer system, that amp is controlled by data communication from the factory radio — it cannot be turned on with a simple +12V remote wire, so standard wiring adapters alone leave the car silent. An iDatalink Maestro interface module is the only solution we know of that keeps the Harman Kardon amp working with an aftermarket head unit, and this package is the complete, pre-programmed, plug-and-play way to get one. It also retains your steering wheel controls — no separate SWC module needed.

Which Maestro module does your Subaru need?

The module is matched to the vehicle's amplifier generation — pick the one for your model in the options below:

Maestro RR (standard — included in the base price):
- 2015-2017 Subaru Legacy and Outback
- 2016-2018 Subaru Forester
- 2016-2018 Subaru WRX and WRX STI
- 2015-2017 Subaru Crosstrek
- 2015-2016 Subaru Impreza

Maestro RR2 (required — the newer amplifier generation):
- 2018-2019 Subaru Legacy and Outback
- 2019-2024 Subaru Forester (including the 2022-2025 Forester Wilderness)
- 2019-2021 Subaru WRX and WRX STI
- 2018-2023 Subaru Crosstrek
- 2017-2023 Subaru Impreza (with the amplified sound system)
- 2019-2022 Subaru Ascent

The RR2 also works in the older vehicles (and can show engine data and vehicle status on compatible head units), but the standard RR cannot be used in the newer ones. Model not listed, or not sure which system you have? Email us with your model, year, and trim and we will confirm the right setup before you order.

Have an older Harman Kardon Subaru?

The 2010-2014 Legacy and Outback and the 2015 WRX/STI use the older Harman Kardon amplifier with a conventional turn-on wire — no Maestro module is needed, and a simpler custom harness does the job for much less. See the 2010-2015 Harman Kardon guide instead.

Choosing your head unit

- iDatalink-compatible units (many Pioneer, Sony, Alpine, and Kenwood models) give the best result: steering wheel controls plus full sound adjustment, including front/rear fade, right on the head unit.
- Budget Android units (ATOTO and similar) work too, but the front/rear fade is fixed at the level we program into the module.
- The head unit must have front RCA pre-outs to feed the Maestro. For the few units without them (the ATOTO A6PF, for example) a line output converter is required — ask us.

For the full walk-through, plus the USB and AM/FM antenna add-ons that finish the job, see our Subaru Harman Kardon install guide.

Upgrading your speakers? See our Subaru Speaker & Tweeter Adapters — plug-and-play for 2005-2026 models including Harman Kardon systems.

What's included:

- iDatalink Maestro interface module (RR or RR2, per your selection), programmed for your exact head unit before we ship
- iDatalink Subaru vehicle harness, matched to your model
- Custom-assembled plug-and-play wiring for your specific head unit's connector — no splicing into the factory harness

Not included: the head unit itself, the dash kit, the USB retention harness, and the AM/FM antenna adapter — the install guide has the complete parts list for your vehicle.

Installation:

Every package is built to order and flashed to your head unit's serial number, so it arrives ready to plug in — build time is about one week. In the vehicle:

1. Remove the factory radio and connect the plug-and-play harness to the factory connectors.
2. Plug the OBDII connector in under the driver's dash (this is how the Maestro reads vehicle data).
3. Connect the plugs, RCA leads, and data/steering-wheel cables to your new head unit.
4. Tuck the Maestro module behind the radio and test.

We will ask for your head unit's serial number in the order options (it is OK to email it after checkout). If you ever switch head units later, the module can be re-flashed for the new radio with iDatalink's Weblink updater.

Purchase:

Price: $304