The Beat-Sonic ENA-3S1 is a plug-and-play amplifier kit that dramatically improves the sound quality of your factory Subaru stereo — and adds a dedicated RCA subwoofer output for easy bass expansion. No cutting, no harness modifications, and no need to replace your head unit or speakers. More clarity. More bass. More detail. All from a single compact unit that installs in under two hours.
Professional local installation available in La Mirada, Southern California. Contact us at info@beatsonicusa.com to book.
Why your factory stereo sounds underwhelming — and how the ENA-3S1 fixes it
Subaru factory head units are built to a cost. The amplifier stage inside your OEM radio or external amplifier is one of the first areas where manufacturers cut corners, resulting in a flat, compressed sound even through otherwise decent factory speakers. The ENA-3S1 solves this by strengthening and optimizing the audio signal before it reaches your factory amplifier — giving it a cleaner, more powerful signal to work with, and allowing your factory system to perform closer to its true potential across all frequency ranges.
Your factory head unit, steering wheel controls, and speakers all stay in place and continue to work exactly as before. You simply get the sound your system was always capable of — finally unlocked. And with the dedicated RCA subwoofer output, adding a powered subwoofer is as simple as running a single RCA cable.
Key features
- Plug-and-play installation — no special tools, no harness modifications, no cutting
- 50W x 4-channel output — significantly more power than factory head unit amplification
- Dedicated RCA subwoofer output — easily add a powered subwoofer without additional wiring complexity
- Harman Kardon compatible — works with or without Harman Kardon. Some models will require an additional required module that is included if you selected "Without Harman Kardon" on the drop down menu.
- High-quality FET op-amp input stage — reproduces fine musical detail including voice tone and breath at high resolution
- Ultra-compact design — flexible installation location, fits easily behind the dash
- Premium acoustic components — low-impedance capacitors and 70μ extra copper thickness for improved frequency response across low, mid, and high ranges
- Retains factory head unit — your display, controls, and all factory features continue to work normally
- Compatible with aftermarket speakers — keep impedance at 4Ω–8Ω when using aftermarket speakers
- Made in Japan
Specifications
- Maximum output: 50W x 4ch (4Ω)
- Compatible impedance: 4–8Ω
- Input sensitivity: 0.5–5V
- Frequency response: 15–80kHz (+0, -1dB)
- Total harmonic distortion: 0.01% (1kHz / 4Ω)
- Power supply: DC12V (minus ground), DC11V–15V range
- Current consumption: 0.2A (no signal)
- Fuse: 15A
- Audio output: AUX level (RCA) + speaker level (high-level input)
- Dimensions: 96mm (W) x 40mm (D) x 113.5mm (H)
- Weight: 420g
Compatible vehicles
The ENA-3S1 is compatible with the following Subaru and Toyota models:
- 2022–2026 Toyota GR86
- 2013–2026 Subaru BRZ
- 2018–2026 Subaru Forester — without Harman Kardon requires VAZ-A02K module
- 2021–2026 Subaru Impreza — without Harman Kardon requires VAZ-A02K module
- 2021–2025 Subaru Legacy — without Harman Kardon requires VAZ-A02K module
- 2016–2019 Subaru Outback
- 2020–2025 Subaru Outback — without Harman Kardon requires VAZ-A02K module
- 2016–2021 Subaru WRX
- 2022–2026 Subaru WRX — without Harman Kardon requires VAZ-A02K module
- 2016–2019 Subaru XV Crosstrek
- 2022–2026 Subaru XV Crosstrek — without Harman Kardon requires VAZ-A02K module
Note on Harman Kardon models and RCA subwoofer output: The ENA-3S1's RCA subwoofer outputs are compatible with non-Harman Kardon models only. On Harman Kardon-equipped vehicles, there is a known issue where the radio's volume control does not control the aftermarket subwoofer connected via the RCA outputs — meaning if the vehicle volume is set to 0, the subwoofer will still play. The workaround is to use a subwoofer with a separate bass volume control knob. If you do not plan on adding an aftermarket subwoofer via the RCA outputs, this issue does not affect you and the ENA-3S1 will otherwise function normally on compatible Harman Kardon models.
Not sure which option applies to your vehicle? Email info@beatsonicusa.com with your year, model, trim, and audio system before purchasing.
Installation
No special tools required. No modifications to the factory wiring harness. Most owners complete the install in under two hours using our step-by-step YouTube video guides. Professional installation is available in Southern California through Beat-Sonic directly, or through our authorized installer network worldwide. Email info@beatsonicusa.com with your location or zip code to find the nearest shop.
Frequently asked questions
Will I need to replace my factory speakers or head unit?
No. The ENA-3S1 works with your existing factory head unit and speakers. You keep everything in place — the amp simply adds power and clarity to what you already have.
Is this compatible with aftermarket head units?
The ENA-3S1 works with aftermarket head units as long as the factory head unit retains the factory connectors that our ENA-3S1 plug and play harness connects to.
Is this compatible with Harman Kardon factory systems?
Yes, Harman Kardon equipped models are compatible. When placing your order, select your audio system option (with or without Harman Kardon) to ensure you receive the correct harness configuration. If you are unsure which option applies to your vehicle, email info@beatsonicusa.com with your year, model, and trim before purchasing.
What is the VAZ-A02K module and do I need it?
The VAZ-A02K is a required adapter module for select newer Subaru models without Harman Kardon. If your vehicle is listed with "without Harman Kardon requires VAZ-A02K" in the compatibility list above, simply select "Without Harman Kardon (includes required module)" when ordering — the module will be included with your kit.
Can I add a powered subwoofer using the RCA outputs on a Harman Kardon-equipped model?
The ENA-3S1's RCA subwoofer outputs are compatible with non-Harman Kardon models only. On Harman Kardon-equipped vehicles, the radio's volume control does not control the aftermarket subwoofer connected via the RCA outputs — meaning if the vehicle volume is set to 0, the subwoofer will still play. We are currently working on a solution. In the meantime, the workaround is to use a subwoofer with a separate bass volume control knob. If you do not plan on adding an aftermarket subwoofer via the RCA outputs, this issue does not affect you.
Can I add a powered subwoofer with this amp?
Yes. The ENA-3S1 includes a dedicated RCA subwoofer output specifically for easy subwoofer expansion. Simply run an RCA cable from the sub output to your powered subwoofer.
Can I use aftermarket speakers with this amp?
Yes. If using new aftermarket speakers, keep the impedance at 4Ω–8Ω for non-amplified models.
Will my steering wheel controls still work?
Yes. All factory features including steering wheel controls and your factory display continue to work normally.
What is the RMS output vs. peak output?
The 50W x 4ch rating is peak output. RMS is the continuous power output your amp delivers — peak is during short bursts. This is standard across the amplifier industry.
How long does installation take?
Most installs take about 2 hours following our YouTube video guide. Professional installation is available in Southern California or through our authorized installer network worldwide.
Does this ship to Canada or internationally?
Yes. We ship to Canada and Mexico.