Subaru STI (GD) Amp + Speakers + Head Unit

We gave this customer's Subaru WRX STI a thorough sound system upgrade. The customer supplied a 4CH amp from MTX that can output about 75W RMS for the door speakers. We also upgraded the infotainment and got rid of the factory CD changer head unit.

The parts we installed were:

Generous sound deadening is recommended for these cars as the metal is very thin and the frameless door windows make for a very flimsy feeling door slam. We were able to reuse the factory tweeter bracket with some bending for the aftermarket tweeter. Most tweeters will fit this vehicle but the door speakers proved to be tricky. Modifications must be made to the door card and spacers or speaker brackets need to be used to prevent the speaker from hitting the window.

The factory speakers are cheap clear plastic and sound awful by modern standards. Additionally, we noticed that the speaker terminals had some corrosion and moisture had gotten on them. It is a good idea to replace some of this wire to prevent issues down the road, we did not want to use speaker harness adapters for this reason. The amp sits nicely under the passenger seat with minimal intrusion into the rear seat legroom. 

With a job like this we would recommend a 5-CH amp to add a modest subwoofer in the trunk without much additional wiring. It's easy to upgrade this amp down the road as well.

For a quote on upgrading your vehicle's sound system, contact us at

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Subaru GD STI door speakers

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Subaru GD STI 4CH amp

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Subaru sti factory speaker terminals