Garage
Shop

2015 Subaru WRX STI

Use our shopping filters to find the right 2/3/4-channel amp to power upgraded speakers properly.

Amps for Adding Speakers for 2015 Subaru WRX STI

Some vehicles require an amp bypass module, a line-output converter like the NVX XLCA2 or AudioControl LC2i, or a DSP to integrate with your factory radio and avoid bass roll-off. Bass roll-off occurs when a factory radio's crossover is designed only for the original equipment speakers, resulting in a not complete signal being sent to your new aftermarket amp.

Loading...
Filters
filter-icon Filters & Sort

Diamond Audio HXM800.4D

800W RMS Class D Motorsport Series 4-Channel Full Range Car, Marine and Powersport Amplifier with Bluetooth

HXM800.4D big
Go to item page Right Arrow Icon of Right Arrow

800W RMS Class D Motorsport Series 4-Channel Full Range Car, Marine and Powersport Amplifier with Bluetooth

• 120 watts x 4 channel @ 4 ohm
• 200 watts x 4 channel @ 2 ohm
• Bridged: 400 watts x 2 channel @ 4 ohm
• Total RMS Power: 800 watts
• Class D 2 ohm Stable 4-Channel Amplifier

2+ offers available
shipping truck icon Free shipping in USA. Provide zip for delivery date.
VIP Star Icon

VIP Product Get $65.00 in rewards to spend later

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

List price $679.99
$649.99

In stock

Continue to cart

Available Offers (2) for Diamond Audio HXM800.4D
FREE NVX Amp Kit at Checkout!
Save 30% off an NVX XKIT84 Amp Kit at Checkout! Add a qualifying amplifier to your cart and save 30% on the NVX XKIT84 Amp Kit! No code needed — discount applies automatically at checkout.
Limited time!

DS18 FRP-1.2K4/TI

1200W RMS Class D FRP Series 4-Channel Car Amplifier (Titanium)

FRP-1.2K4/TI big
Go to item page Right Arrow Icon of Right Arrow

1200W RMS Class D FRP Series 4-Channel Car Amplifier (Titanium)

• 120 watts x 4 channel @ 4 ohm
• 200 watts x 4 channel @ 2 ohm
• 300 watts x 4 channel @ 1 ohm
• Bridged: 350 watts x 2 channel @ 4 ohm
• Bridged: 500 watts x 2 channel @ 2 ohm
• Total RMS Power: 1200 watts
• Class D 1 ohm Stable 4-Channel Amplifier

Save 30% off an NVX XKIT44 Amp Kit at Checkout!
shipping truck icon Free shipping in USA. Provide zip for delivery date.
VIP Star Icon

VIP Product Get $30.00 in rewards to spend later

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

List price $359.99
-17% $299.95

In stock.


Available Deal
FRP-1.2K4/TI main
Offer may end without notice

Eligible items

Shop items below for 30% off up to $100 discount on Save 30% off an NVX Amp Kit!

NVX XKIT44

$119.99

$83.99

$36 Savings!

Add to cart

• 120 watts x 4 channel @ 4 ohm
• 200 watts x 4 channel @ 2 ohm
• 300 watts x 4 channel @ 1 ohm
• Bridged: 350 watts x 2 channel @ 4 ohm
• Bridged: 500 watts x 2 channel @ 2 ohm
• Total RMS Power: 1200 watts
• Class D 1 ohm Stable 4-Channel Amplifier

Limited time!

Kenwood KAC-M8005

800W RMS Class D M Series 5-Channel Marine Amplifier

KAC-M8005 big
Go to item page Right Arrow Icon of Right Arrow

800W RMS Class D M Series 5-Channel Marine Amplifier

• 50 watts x 4 channel + 300 watts x 1 channel @ 4 ohm
• 75 watts x 4 channel + 500 watts x 1 channel @ 2 ohm
• 700 watts x 1 channel @ 1 ohm (subwoofer output)
• Bridged: 150 watts x 2 channel @ 4 ohm
• Total RMS Power: 800 watts
• Class D 2 ohm Stable 5-Channel Amplifier

FREE Belva Amp Kit at Checkout!
shipping truck icon Free shipping in USA. Provide zip for delivery date.
VIP Star Icon

VIP Product Get $49.90 in rewards to spend later

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

List price $520.00
$499.00

In stock

Only 2 Left!

• 50 watts x 4 channel + 300 watts x 1 channel @ 4 ohm
• 75 watts x 4 channel + 500 watts x 1 channel @ 2 ohm
• 700 watts x 1 channel @ 1 ohm (subwoofer output)
• Bridged: 150 watts x 2 channel @ 4 ohm
• Total RMS Power: 800 watts
• Class D 2 ohm Stable 5-Channel Amplifier

Limited time!

Wet Sounds STX MICRO-4

560W Peak Class D Stealth STX Series 4 Channel Compact Marine and Powersports Amplifier

STX Micro-4 big
Go to item page Right Arrow Icon of Right Arrow

560W Peak Class D Stealth STX Series 4 Channel Compact Marine and Powersports Amplifier

• @ 4 ohm
• @ 2 ohm
• Bridged: @ 4 ohm
• Total RMS Power:
• Class D 2 ohm Stable 4-Channel Amplifier

FREE NVX Amp Kit at Checkout!
shipping truck icon Free shipping in USA. Provide zip for delivery date.
VIP Star Icon

VIP Product Get $50.00 in rewards to spend later

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

$499.99

Available

Ships in 10-14 days

Wet Sounds Sinister-SDX6

1755W RMS Class D Sinister Series 6 Channel Marine Amplifier

Sinister-SDX6 big
Go to item page Right Arrow Icon of Right Arrow

1755W RMS Class D Sinister Series 6 Channel Marine Amplifier

• 185 watts x 6 channel @ 4 ohm
• 290 watts x 6 channel @ 2 ohm
• Bridged: 585 watts x 3 channel @ 4 ohm
• Total RMS Power: 1755 watts
• Class D 2 ohm Stable 6-Channel Marine Amplifier

shipping truck icon Free shipping in USA. Provide zip for delivery date.
VIP Star Icon

VIP Product Get $190.00 in rewards to spend later

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

$1,899.99

Available

Ships in 10-14 days

• 185 watts x 6 channel @ 4 ohm
• 290 watts x 6 channel @ 2 ohm
• Bridged: 585 watts x 3 channel @ 4 ohm
• Total RMS Power: 1755 watts
• Class D 2 ohm Stable 6-Channel Marine Amplifier

MB Quart RA1-150.2

100W RMS Class D Reference Series 2 Channel Car Amplifier

RA1-150.2 big
Go to item page Right Arrow Icon of Right Arrow

100W RMS Class D Reference Series 2 Channel Car Amplifier

• 50 watts x 2 channel @ 4 ohm
• 100 watts x 2 channel @ 2 ohm
• Bridged: 200 watts x 1 channel @ 4 ohm
• Total RMS Power: 200 watts
• Class D 2 ohm Stable 2-Channel Amplifier

2+ offers available
shipping truck icon Free shipping in USA. Provide zip for delivery date.
VIP Star Icon

VIP Product Get $26.25 in rewards to spend later

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

$262.50

In stock

Only 1 Left!

Continue to cart

Available Offers (2) for MB Quart RA1-150.2
FREE Belva Amp Kit at Checkout!
Save 30% on an NVX XKIT42 Amp Kit with Purchase! Add a qualifying amplifier to your cart and save 30% on the NVX XKIT42 Amp Kit! No code needed — discount applies automatically at checkout.

NVX NBA201 (Open Box, Great)

1400W Peak (700W) RMS N-Series Class A/B 2-Channel Amplifier

NBA201 big
Go to item page Right Arrow Icon of Right Arrow

1400W Peak (700W) RMS N-Series Class A/B 2-Channel Amplifier

• 200 watts x 2 channel @ 4 ohm
• 350 watts x 2 channel @ 2 ohm
• Bridged: 700 watts x 1 channel @ 4 ohm
• Total RMS Power: 700 watts
• CEA-2006 Compliant

shipping truck icon Free shipping in USA. Provide zip for delivery date.

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

1
List price $249.99
-48% $129.99

In stock

Only 2 Left!

Rockford Fosgate Punch Marine PM400X4

400W RMS Class AB Punch Series 4 Channel Marine Amplifier

PM400X4 big
Go to item page Right Arrow Icon of Right Arrow

400W RMS Class AB Punch Series 4 Channel Marine Amplifier

• 50 watts x 4 channel @ 4 ohm
• 100 watts x 4 channel @ 2 ohm
• Bridged: 200 watts x 2 channel @ 4 ohm
• Total RMS Power: 400 watts
• Class A/B 2 ohm Stable 4-Channel Amplifier

shipping truck icon Free shipping in USA. Provide zip for delivery date.
VIP Star Icon

VIP Product Get $52.00 in rewards to spend later

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

1
$519.99

Available

Ships in 10-14 days

• 50 watts x 4 channel @ 4 ohm
• 100 watts x 4 channel @ 2 ohm
• Bridged: 200 watts x 2 channel @ 4 ohm
• Total RMS Power: 400 watts
• Class A/B 2 ohm Stable 4-Channel Amplifier

Wet Sounds SYN-DX4

800W Peak Class D SYN-DX Series 4 Channel Marine Amplifier

SYN-DX4 big
Go to item page Right Arrow Icon of Right Arrow

800W Peak Class D SYN-DX Series 4 Channel Marine Amplifier

• @ 4 ohm
• @ 2 ohm
• Bridged: @ 4 ohm
• Total RMS Power:
• Class D 2 ohm Stable 4-Channel Amplifier

shipping truck icon Free shipping in USA. Provide zip for delivery date.
VIP Star Icon

VIP Product Get $120.00 in rewards to spend later

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

$1,199.99

Available

Ships in 10-14 days

Used from: $839.99

• @ 4 ohm
• @ 2 ohm
• Bridged: @ 4 ohm
• Total RMS Power:
• Class D 2 ohm Stable 4-Channel Amplifier

DS18 SXE-2000.4D/BK

2000W Peak (640W RMS) Class D SXE Series 4 Channel Car Amplifier

SXE-2000.4D/BK big
Go to item page Right Arrow Icon of Right Arrow

2000W Peak (640W RMS) Class D SXE Series 4 Channel Car Amplifier

• 100 watts x 4 channel @ 4 ohm
• 160 watts x 4 channel @ 2 ohm
• Bridged: 320 watts x 2 channel @ 4 ohm
• Total RMS Power: 640 watts
• Class D 2 ohm Stable 4-Channel Amplifier
• Black Brushed Aluminum Body Color

shipping truck icon Free shipping in USA. Provide zip for delivery date.
VIP Star Icon

VIP Product Get $24.00 in rewards to spend later

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

$239.95

In stock

Only 3 Left!

Wet Sounds HTM-8

1200W RMS Class D HTM Series 8 Channel Marine Amplifier with LED Backlit Badge

HTM-8 big
Go to item page Right Arrow Icon of Right Arrow

1200W RMS Class D HTM Series 8 Channel Marine Amplifier with LED Backlit Badge

• 85 watts x 8 channel @ 4 ohm
• 150 watts x 8 channel @ 2 ohm
• Bridged: 300 watts x 4 channel @ 4 ohm
• Total RMS Power: 1200 watts
• Class D 2 ohm Stable 8-Channel Amplifier

Shipping Credit Applied
shipping truck icon Free shipping in USA. Provide zip for delivery date.
VIP Star Icon

VIP Product Get $100.00 in rewards to spend later

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

$999.99

In stock

Only 1 Left!

• 85 watts x 8 channel @ 4 ohm
• 150 watts x 8 channel @ 2 ohm
• Bridged: 300 watts x 4 channel @ 4 ohm
• Total RMS Power: 1200 watts
• Class D 2 ohm Stable 8-Channel Amplifier

Limited time!

MTX PS200.2

200W RMS Class D PS Series 2-Channel Powersports Amplifier

PS200.2 big
Go to item page Right Arrow Icon of Right Arrow

200W RMS Class D PS Series 2-Channel Powersports Amplifier

• 50 watts x 2 channel @ 4 ohm
• 100 watts x 2 channel @ 2 ohm
• Bridged: 200 watts x 1 channel @ 4 ohm
• Total RMS Power: 200 watts
• Class D 2 ohm Stable 2-Channel Amplifier

shipping truck icon Free shipping in USA. Provide zip for delivery date.

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

List price $379.95
Save $123.99
-33% $255.96

Available

Ships in 10-14 days

• 50 watts x 2 channel @ 4 ohm
• 100 watts x 2 channel @ 2 ohm
• Bridged: 200 watts x 1 channel @ 4 ohm
• Total RMS Power: 200 watts
• Class D 2 ohm Stable 2-Channel Amplifier

Limited time!

Cerwin Vega SRPM700.4DW

700W RMS Class D Stroker RPM Series 4-Channel Marine Amplifier (White)

SRPM700.4DW big
Go to item page Right Arrow Icon of Right Arrow

700W RMS Class D Stroker RPM Series 4-Channel Marine Amplifier (White)

• 100 watts x 4 channel @ 4 ohm
• 150 watts x 4 channel @ 2 ohm
• Bridged: 300 watts x 2 channel @ 4 ohm
• Total RMS Power: 700 watts
• Class D 2 ohm Stable 4-Channel Amplifier

FREE NVX Amp Kit at Checkout!
shipping truck icon Free shipping in USA. Provide zip for delivery date.
VIP Star Icon

VIP Product Get $43.00 in rewards to spend later

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

List price $515.99
-17% $429.99

In stock.

Limited time!

Kicker PXA400.4 (48PXA4004)

800W Peak (400W RMS) Class D PXA Series 4-Channel Marine and Powersports Amplifier

PXA400.4 big
Go to item page Right Arrow Icon of Right Arrow

800W Peak (400W RMS) Class D PXA Series 4-Channel Marine and Powersports Amplifier

• 100 watts x 4 channel @ 4 ohm
• 150 watts x 4 channel @ 2 ohm
• Bridged: 200 watts x 2 channel @ 4 ohm
• Total RMS Power: 400 watts
• Class D 2 ohm Stable 4-Channel Amplifier

shipping truck icon Free shipping in USA. Provide zip for delivery date.
VIP Star Icon

VIP Product Get $40.00 in rewards to spend later

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

List price $549.99
Save $150.03
-27% $399.96

Available

Ships in 10-14 days

JBL Club A5055 (AMPCBA5055AM) + NVX XKIT46

Class AB + D High Performance 5-Channel Amplifier + NVX XKIT46 4 Gauge 6-Channel Amp Wirring Kit

Club A5055, XKIT46 big
Go to item page Right Arrow Icon of Right Arrow

Class AB + D High Performance 5-Channel Amplifier + NVX XKIT46 4 Gauge 6-Channel Amp Wirring Kit

• Class AB + D Amp Technology
• 4 Ohm: 50 Watts RMS x 4 + 320 Watts RMS x 1
• Variable Crossover and Bass Boost
• Variable High and Low-Pass Filters
• Full on Board Protection

Save 15% Off Package Deals at Checkout!
shipping truck icon Free shipping in USA. Provide zip for delivery date.

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

48
List price $709.94
-23% $544.94

In stock

• Class AB + D Amp Technology
• 4 Ohm: 50 Watts RMS x 4 + 320 Watts RMS x 1
• Variable Crossover and Bass Boost
• Variable High and Low-Pass Filters
• Full on Board Protection

Hertz HMD8 DSP

1040W RMS Class D Hertz Marine Series (HMS) 8-Channel Marine Amplifier with Digital Signal Processor

HMD8 DSP big
Go to item page Right Arrow Icon of Right Arrow

1040W RMS Class D Hertz Marine Series (HMS) 8-Channel Marine Amplifier with Digital Signal Processor

• 85 watts x 8 channel @ 4 ohm
• 130 watts x 8 channel @ 2 ohm
• Bridged: 260 watts x 4 channel @ 4 ohm
• Total RMS Power: 1040 watts
• Class D 2 ohm Stable 8-Channel-Channel Marine Amplifier with Digital Signal Processor

shipping truck icon Free shipping in USA. Provide zip for delivery date.
VIP Star Icon

VIP Product Get $160.00 in rewards to spend later

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

List price $1825.00
-12% $1,599.99

Available

Ships in 10-14 days

Rockford Fosgate Power T400X2ad

400W RMS Class AD Power Series 2 Channel Amplifier

T400X2AD big
Go to item page Right Arrow Icon of Right Arrow

400W RMS Class AD Power Series 2 Channel Amplifier

• 200 watts x 2 channel @ 4 ohm
• 200 watts x 2 channel @ 2 ohm
• Bridged: 400 watts x 1 channel @ 4 ohm
• Total RMS Power: 400 watts
• Class AD 2 ohm Stable 2-Channel Amplifier

2+ offers available
shipping truck icon Free shipping in USA. Provide zip for delivery date.
VIP Star Icon

VIP Product Get $46.00 in rewards to spend later

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

$459.99

In stock

Only 1 Left!

Continue to cart

Available Offers (2) for Rockford Fosgate Power T400X2ad
FREE NVX Amp Kit at Checkout!
Save 30% off an NVX XKIT82 Amp Kit at Checkout! Add a qualifying amplifier to your cart and save 30% on the NVX XKIT82 Amp Kit! No code needed — discount applies automatically at checkout.
Used from: $390.99

Diamond Audio HXM800.2D

800W RMS Class D MotorSport Series 2-Channel Car, Marine and Powersport Amplifier

HXM800.2D big
Go to item page Right Arrow Icon of Right Arrow

800W RMS Class D MotorSport Series 2-Channel Car, Marine and Powersport Amplifier

• 300 watts x 2 channel @ 4 ohm
• 400 watts x 2 channel @ 2 ohm
• Bridged: 800 watts x 1 channel @ 4 ohm
• Total RMS Power: 800 watts
• Class D 2 ohm Stable 2-Channel Amplifier

2+ offers available
shipping truck icon Free shipping in USA. Provide zip for delivery date.
VIP Star Icon

VIP Product Get $50.00 in rewards to spend later

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

$499.99

In stock

Only 2 Left!

Continue to cart

Available Offers (2) for Diamond Audio HXM800.2D
FREE NVX Amp Kit at Checkout!
Save 30% on an NVX XKIT42 Amp Kit with Purchase! Add a qualifying amplifier to your cart and save 30% on the NVX XKIT42 Amp Kit! No code needed — discount applies automatically at checkout.

Hertz Venezia V6

1740W RMS Class D Venezia Series 6-Channel Marine Amplifier

Venezia V6 big
Go to item page Right Arrow Icon of Right Arrow

1740W RMS Class D Venezia Series 6-Channel Marine Amplifier

• 160 watts x 6 channel @ 4 ohm
• 290 watts x 6 channel @ 2 ohm
• Total RMS Power: 1740 watts
• Class D 2 ohm Stable 6-Channel Amplifier

2+ offers available
shipping truck icon Free shipping in USA. Provide zip for delivery date.
VIP Star Icon

VIP Product Get $140.00 in rewards to spend later

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

List price $1600.00
-13% $1,399.99

In stock

Only 1 Left!

Continue to cart

Available Offers (2) for Hertz Venezia V6
FREE Belva Amp Kit at Checkout!
Save 30% off an NVX XKIT06 Amp Kit at Checkout! Add a qualifying amplifier to your cart and save 30% on the NVX XKIT06 Amp Kit! No code needed — discount applies automatically at checkout.

Deaf Bonce Machete MFA 2.220

700W RMS Class D Machete Series 2-Channel Car Amplifier

MFA 2.220 big
Go to item page Right Arrow Icon of Right Arrow

700W RMS Class D Machete Series 2-Channel Car Amplifier

• 220 watts x 2 channel @ 4 ohm
• 350 watts x 2 channel @ 2 ohm
• Bridged: 700 watts x 1 channel @ 4 ohm
• Total RMS Power: 700 watts
• Class D 2 ohm Stable 2-Channel-Channel Amplifier

shipping truck icon Free shipping in USA. Provide zip for delivery date.

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

$189.90

In stock

• 220 watts x 2 channel @ 4 ohm
• 350 watts x 2 channel @ 2 ohm
• Bridged: 700 watts x 1 channel @ 4 ohm
• Total RMS Power: 700 watts
• Class D 2 ohm Stable 2-Channel-Channel Amplifier

Items per page: 20 40 60

    Clear all
    why-shoping-with-sonic

    We love people and we're ready to help you! See what separates us from our competition.

    Take advantage of our VIP rewards like 10% back on your purchases, free 2-day shipping, extended warranties, and free returns! Gain access to all of these rewards without any membership fees.
    Get great discounted (and possibly FREE) installation accessories with most car stereo purchases. This includes dash kits, wiring harnesses and antenna adapters that you will need to properly install your new car stereo.
    We are an Authorized Dealer for all the brands we sell, including the most premium brands in car and marine audio such as Hertz, JL Audio, NVX, Rockford Fosgate, Kicker, Alpine, Kenwood and many more.
    Shop Deals and get up to 30% off premium brands! Shop Now! We are always looking out for the best products and deals to offer our customers. Don’t pay too much by shopping elsewhere!
    We have information on brands, gear, and more for you to explore! Check out our YouTube Channel for helpful how-to videos, product reviews, and Q&As. For a more detailed look, also visit our Learning Center!
    Our trained experts are here to assist you! They are just a phone call or click away to help you get the right gear for you and your vehicle!
    Why Shop With Us?
    FAQ for Multi-channel Amplifiers for Adding Speakers in 2015 WRX STI

    Q: Can I upgrade or change the Multi-channel Amplifiers for Adding Speakers in 2015 Subaru WRX STI?

    A: Yes this page includes all the best Multi-channel Amplifiers for Adding Speakers that work in your WRX STI.

    Save up to 10 different vehicles in your garage
    Vehicle
    Store
    Delete

    2015 Subaru WRX STI

    2005 Acura TL

    2009 Mercedes-Benz E-Class

    2008 Jeep Compass

    1992 Audi 100 Quattro

    2013 BMW 740Li

    2000 Lincoln Continental

    1995 GMC C2500 Suburban

    2023 Chevrolet Blazer

    2017 Alfa Romeo 4C Spider

    Vehicle
    Store
    Delete

    2001 Harley Davidson FLTR/I Road Glide

    2009 Harley Davidson FLHTC Electra Glide Classic

    Add vehicle Clear all vehicles
    Where to find vehicle info
    Are you sure you want to clear your garage?
    This action cannot be undone. Confirm
    This category was not designed for products.
    If you continue, you will be redirected to a category customized for your vehicle. Continue
    Loading...
    Identify your vehicle and submodel details
    • Owner's manual
    • Vehicle's insurance card
    • Vehicle registration
    • Vehicle produced after 2005: Inside driver's side door
    • Vehicle produced before 2005: Rear passenger doorjamb, glove box, center console, or engine compartment
    Car Info Side Door Icon
    Vehicle Registration Icon
    Vehicle Insurance Icon

    Modern vehicles often require specific brackets, wiring harnesses, and mounting solutions. A fit guide ensures:

    • You see only parts engineered for your exact vehicle
    • You avoid incompatible radios, speakers, or wiring
    • Installation is smoother, faster, and frustration-free
    • You get the correct accessories the first time

    Whether you're replacing a factory stereo or upgrading your entire audio system, the Fit Finder eliminates uncertainty.