Garage
Shop
Account Icon
Account
Box Icon
Track
order
Telephone Icon
Call
Help Icon
Help
Door with Arrow Icon
Sign In

2005 Smart Fortwo

Change vehicle | Remove vehicle

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

Overview Upgrade your Speakers Add a Subwoofer Add an Amplifier Digital Sound Processors Audio Installation & Accessories Add a Backup Camera Dads & Grads Sale

Amps for Adding Speakers for 2005 Smart Fortwo

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.

Filters
Reset Done
Product Type
Price Range
Product Fitment Type
Number of Channels
Each channel on an amplifier will power one speaker using a positive and negative cable. There are various types of amplifiers, each designed to power a certain number of speakers. Monoblock amplifiers, also known as single channel, are designed to power one or more subwoofers. These amplifiers often have very high power ratings. On the other hand, multi-channel amplifiers power multiple speakers, usually at lower power ratings. 2-Channel and 4-Channel amplifiers can power car speakers or low powered subwoofers. Occasionally you might see a 5 or 6-channel amplifier that can power speakers and subwoofers at the same time. The most common setup is a monoblock amp to run subwoofers and a 4-channel amp to run door speakers. Check out our Knowledge Base for more information.
Amplifier Key Features
Amplifiers can offer a diverse array of features. If you select more than one feature, then you will view amplifiers that have ALL features selected. These include speaker-level inputs that facilitate seamless integration with factory audio systems, Bluetooth connectivity suitable for ATV/UTV or Classic vehicle setups, built-in DSPs that provide enhanced control over your audio signal, and a host of other functionalities to explore.
Amplifier Class

An amplifier increases the power of the signal being fed to it by taking energy from its power supply and matching the signal but increasing its amplitude. Amplifiers use many different methods for converting these electrical signals and have been categorized into classes.

Class A/B: Greater than 50% of the input signal is amplified while the other percentage is “off”. These amplifiers have a small amount of current flowing through the output transistors all the time which almost eliminates crossover distortion. Class A/B has great sound quality but is not as efficient as class D. These amps are most commonly used to drive speakers.

Class D: Also known as switching amplifiers, class D amps have output transistors that are completely turned “on” or “off”. This means that when the transistors are on, there is almost no voltage across them but when they are off there is significant voltage but no current flowing through it which makes these amplifiers very efficient at the cost of sound quality. These amps are most commonly used to drive subwoofers.

Other Classes: You may see classes such as GH, bD, X, FD, etc. by some manufactures. These amplifiers tend to be either class A/B, D or a hybrid of the two but with improvements to their designs that can make them more efficient or offer better sound quality.
Total RMS Power Output
Total RMS power is measured by multiplying RMS power per channel by the number of channels, and is calculated at the lowest level of operating impedance.

RMS power is the amount of continuous power, measured in watts, that an amplifier produces is called RMS power. The higher the RMS figure, the louder and cleaner your music sounds.

The RMS output figure is much more accurate than the peak rating when comparing products.
Total Peak Power Output
The total peak power output is measured as the wattage per channel multiplied by the number of channels, and is calculated at the lowest level of operating impedance.

It is measured during a brief musical burst, such as a sudden drum accent. Some manufacturers display peak power ratings on the face of their products to increase the appeal.

The RMS power rating is more accurate, and we recommend using it for product comparison.
Series
Many brands group their products into series or lines of products to help customers know the level of quality (good, better, best for example). You can filter by series and the brand using our guided browsing.
Punch Series (32)
Machete Series (19)
V Series (16)
Power Series (15)
XDM Series (15)
Prime Series (13)
Hydro Series (12)
CVP Series (11)
FRP Series (9)
SXE Series (9)
VXi Series (9)
Gen-X (8)
Ground Pounder Series (7)
MVi Series (7)
Reference Series (7)
eXcelon Series (6)
KXM Series (6)
M2 Series (6)
Marine V Series (6)
Nautic Series (6)
RD Series (6)
SMD Series (6)
BX Series (5)
Club Series (5)
Elite Series (5)
HED Series (5)
MUD Series (5)
N Series (5)
SAE Series (5)
Stroker Pro Series (5)
SYN-DX Series (5)
Thunder Series (5)
VEGA Series (5)
Venezia Series (5)
Apocalypse Sport Series (4)
Brutus BG Series (4)
CRA Series (4)
CX Series (4)
DSP Series (4)
HCP Series (4)
HEX Series (4)
iON Series (4)
JA Series (4)
KM Series (4)
MA Series (4)
Mean Machine Series (4)
Micro Series (4)
MX Series (4)
R-Series (4)
SALT Series (4)
SFB Series (4)
Stealth Bomber Series (4)
Stroker RPM Series (4)
V-Drive Series (4)
XED Series (4)
ACX Series (3)
AP Series (3)
Apex Series (3)
Apocalypse Atom Pro Series (3)
Bomber Series (3)
Brutus BRL Series (3)
D Series (3)
Diamond Elite Series (3)
Discus Series (3)
DXM Series (3)
Epic Series (3)
GM Series (3)
HD Series (3)
HTM Series (3)
JD Series (3)
Kappa Perfect Series (3)
LX Series (3)
M Series (3)
Marine Series (3)
NXL Series (3)
Power Pack Series (3)
Premium Pro Series (3)
PS Series (3)
Rebel Series (3)
S Series (3)
Sinister Series (3)
Stroker Series (3)
Terminator Series (3)
Trident Series (3)
X Series (3)
Zeus Series (3)
ZR Series (3)
Altitude Series (2)
Buran Series (2)
COLOSSUS Mini Series (2)
COLOSSUS Series (2)
Compact Mean Machine Series (2)
Competition Series (2)
DB Series (2)
DMD Series (2)
DRVN Series (2)
Edge Series (2)
Excelon Motorsports Series (2)
Excelon Reference Series (2)
Formula Series (2)
Godfather Series (2)
Hooligan Series (2)
HRPM Series (2)
HXM Series (2)
LC Series (2)
M5 Series (2)
MDX Series (2)
MHD Series (2)
MicroV2 Series (2)
N-Series (2)
Punch BR Series (2)
PXA Series (2)
QS Series (2)
SAM Series (2)
Signature Series (2)
SPL Show Series (2)
Stage GT Series (2)
Status Series (2)
Stealth Mini Series (2)
VFL Series (2)
WET Series (2)
ACM Series (1)
Alpha Series (1)
Atom Series (1)
CVPRO Series (1)
DC Series (1)
DS Series (1)
EV Series (1)
FX Series (1)
GT Series (1)
HCCA Series (1)
HMS Series (1)
HMP Series (1)
HTX Series (1)
Key Series (1)
KPX Series (1)
Micro8U Series (1)
Mille Pro Series (1)
MINI BANG Series (1)
Mini Series (1)
MotorSport Series (1)
Performance Series (1)
Picasso-Nano Series (1)
PowerZone 2 Series (1)
Primo Series (1)
Primus Series (1)
PXE Series (1)
Q-Series (1)
RPM Series (1)
RTX Series (1)
Smash Series (1)
SPL (1)
SPX Series (1)
Stealth STX Series (1)
VFL Comp Series (1)
VFL Stealth Series (1)
Warhorse Series (1)
XC-Series (1)
XFL Series (1)
XQ Series (1)
ZXI Series (1)
Minimum Impedance Unbridged
The lowest impedance the amplifier will handle when it is not bridged.
Minimum Impedance Bridged
The lowest impedance the amplifier will handle when it is bridged.
Remote bass/level controller
If the amp comes with a bass/gain remote you will be able to control the level of your bass from your dashboard. Typically bass remotes also include a 16-20 ft. wire for installation.
Sonic Certified Amplifier
Sonic Certified amplifiers have been tested by the experts at Sonic Electronix to meet or exceed the wattage ratings provided by the manufacturer. If this is marked as Yes, then you can trust the wattage ratings. If marked as No, then we have tested the amplifier and it did not meet the advertised wattage ratings. If marked as Not Tested, then the Sonic Electronix experts have not yet been able to test the amp.
Preamp Outputs
Many amplifiers are equipped with RCA preamp outputs which pass the original music signal from the source to additional amplifiers. This is known as daisy chaining because the source connects to the first amp, and the first amp connects to the second amp, etc. The advantage to daisy chaining is you only need one 2-channel RCA cable to transfer the signal from the head-unit to the amplifier, and then one additional cable for each amp being daisy chained.
Built-in Crossover

A crossover is a type of filtering system that permits only certain frequencies to play. A Low-Pass (LP) crossover allows only frequencies below its setting to get through which is good in the case of some subwoofers. A High-Pass(HP) filter allows frequencies above its setting to pass through, this is normally used on speakers.

When a crossover is set to FULL it means no filtering is added and the full frequency spectrum is allowed through the amplifier. Filtering is important because feeding a speaker frequencies it cannot reproduce effectively creates distortion.

Amp Bluetooth Connectivity
This feature will tell you if the amplifier has the capability to connect to a Bluetooth device.
Deals
Promotions we have offer More Ways to Shop for items that are on clearance, last chance, special offer and sales, Made in America, and more!
Condition
Availability
filter-icon Filters & Sort

DC Audio 90.4

520W RMS Class AB Competition Series 4-Channel Car Amplifier (with Bass Remote)

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

DC Audio 90.4

520W RMS Class AB Competition Series 4-Channel Car Amplifier (with Bass Remote)

• 90 watts x 4 channel @ 4 ohm
• 130 watts x 4 channel @ 2 ohm
• Bridged: 250 watts x 2 channel @ 4 ohm
• Total RMS Power: 520 watts
• Class A/B 2 ohm Stable 4-Channel-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

3
List price $621.50
-20% $499.99

In stock.

Add to Cart
Continue to cart
Available Offers (2) for DC Audio 90.4
FREE NVX Amp Kit at Checkout!
Add both to cart
Save 30% off an NVX XKIT44 Amp Kit at Checkout! Add a qualifying amplifier to your cart and save 30% on the NVX XKIT44 Amp Kit! No code needed — discount applies automatically at checkout.
Select your other item
Limited time!

DS18 G1800.4D

1800W Peak (920W RMS) Class D GEN-X Series 4 Channel Full Range Car Amplifier

G1800.4D big
Go to item page Right Arrow Icon of Right Arrow

DS18 G1800.4D

1800W Peak (920W RMS) Class D GEN-X Series 4 Channel Full Range Car Amplifier

• 150 watts x 4 channel @ 4 ohm
• 230 watts x 4 channel @ 2 ohm
• Bridged: 430 watts x 2 channel @ 4 ohm
• Total RMS Power: 920 watts
• Class D 2 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 $28.80 in rewards to spend later

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

$287.95

In stock.

Add to Cart
Available Deal
G1800.4D main
Offer may end without notice
Continue Shopping Continue to checkout
Eligible items

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

NVX XKIT44

NVX XKIT44

$119.99

$83.99

$36 Savings!

Add to cart
Limited time!

DS18 FRP-1.2K4/BL

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

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

DS18 FRP-1.2K4/BL

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

• 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.

Add to Cart
Available Deal
FRP-1.2K4/BL main
Offer may end without notice
Continue Shopping Continue to checkout
Eligible items

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

NVX XKIT44

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

Cerwin Vega S9500.2D

500W RMS Class D Stroker Series 2-Channel Car Amplifier with Bass Remote

S9500.2D big
Go to item page Right Arrow Icon of Right Arrow

Cerwin Vega S9500.2D

500W RMS Class D Stroker Series 2-Channel Car Amplifier with Bass Remote

• 200 watts x 2 channel @ 4 ohm
• 250 watts x 2 channel @ 2 ohm
• Bridged: 500 watts x 2 channel @ 4 ohm
• Total RMS Power: 500 watts
• Class D 2 ohm Stable 2-Channel Amplifier

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% $299.99

In stock.

Add to Cart
See all 5 special offers

Diamond Audio DMD1100.6D

1100W RMS Class D DMD Series 6-Channel Car Amplifier

DMD1100.6D big
Go to item page Right Arrow Icon of Right Arrow

Diamond Audio DMD1100.6D

1100W RMS Class D DMD Series 6-Channel Car Amplifier

• 80 watts x 4 channel @ 4 ohm
• 125 watts x 4 channel @ 2 ohm
• Bridged: 250 watts x 2 channel @ 4 ohm
• Total RMS Power: 1100 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 $55.00 in rewards to spend later

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

$549.99

In stock.

Add to Cart
Continue to cart
Available Offers (2) for Diamond Audio DMD1100.6D
FREE NVX Amp Kit at Checkout!
Add both to cart
Save 30% off an NVX XKIT46 Amp Kit at Checkout! Add a qualifying amplifier to your cart and save 30% on the NVX XKIT46 Amp Kit! No code needed — discount applies automatically at checkout.
Select your other item

Cerwin Vega B52

1000W Peak (500W RMS) Class D Stealth Bomber Series 2 Channel Car Amplifier with Bass Remote

B52 big
Go to item page Right Arrow Icon of Right Arrow

Cerwin Vega B52

1000W Peak (500W RMS) Class D Stealth Bomber Series 2 Channel Car Amplifier with Bass Remote

• 150 watts x 2 channel @ 4 ohm
• 250 watts x 2 channel @ 2 ohm
• Bridged: 500 watts x 1 channel @ 4 ohm
• Total RMS Power: 500 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 $33.00 in rewards to spend later

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

1
List price $395.99
-17% $329.99

In stock

Add to Cart
Continue to cart
Available Offers (2) for Cerwin Vega B52
FREE Belva Amp Kit at Checkout!
Add both to cart
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.
Select your other item
See all 6 special offers

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

DS18 SXE-2000.4D/BK

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!

Add to Cart
Limited time!

DS18 FX6

4500W Peak (1500W RMS) Class D FX Series 6-Channel Car Amplifier with LED

FX6 big
Go to item page Right Arrow Icon of Right Arrow

DS18 FX6

4500W Peak (1500W RMS) Class D FX Series 6-Channel Car Amplifier with LED

• 180 watts x 6 channel @ 4 ohm
• 250 watts x 6 channel @ 2 ohm
• Bridged: 500 watts x 3 channel @ 4 ohm
• Total RMS Power: 1500 watts
• Class D 2 ohm Stable 6-Channel-Channel Amplifier

Save 30% off an NVX XKIT46 Amp Kit at Checkout!
shipping truck icon Free shipping in USA. Provide zip for delivery date.
VIP Star Icon

VIP Product Get $84.00 in rewards to spend later

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

List price $1007.99
-17% $839.95

In stock.

Add to Cart
Available Deal
FX6 main
Offer may end without notice
Continue Shopping Continue to checkout
Eligible items

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

NVX XKIT46

NVX XKIT46

$129.99

$90.99

$39 Savings!

Add to cart

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

Rockford Fosgate Power T400X2ad

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

Available

Ships in 10-14 days

Add to Cart
Continue to cart
Available Offers (2) for Rockford Fosgate Power T400X2ad
FREE NVX Amp Kit at Checkout!
Add both to cart
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.
Select your other item
Used from: $390.99
See all 6 special offers

Belva BXA5002 with Belva 8 Gauge Amp kit

250W Max Class AB 2-Ohm Stable 2-Channel Amplifier Package

BXA5002, BAK82BL big
Go to item page Right Arrow Icon of Right Arrow

Belva BXA5002 with Belva 8 Gauge Amp kit

250W Max Class AB 2-Ohm Stable 2-Channel Amplifier Package

• 125 watts x 2 channel @ 4 ohm
• 250 watts x 2 channel @ 2 ohm
• Total Peak Power: 500 watts
• Class A/B 2 ohm Stable 2-Channel-Channel
• Includes Amplifier Wiring Kit

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

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

41
List price $239.94
-67% $79.98

In stock

Add to Cart

• 125 watts x 2 channel @ 4 ohm
• 250 watts x 2 channel @ 2 ohm
• Total Peak Power: 500 watts
• Class A/B 2 ohm Stable 2-Channel-Channel
• Includes Amplifier Wiring Kit

Stinger SPX1000X5

1100W RMS Class D 5-Channel Marine and Powersport Amplifier with Bluetooth and Bass Remote

SPX1000X5 big
Go to item page Right Arrow Icon of Right Arrow

Stinger SPX1000X5

1100W RMS Class D 5-Channel Marine and Powersport Amplifier with Bluetooth and Bass Remote

• 95 watts x 4 channel + 275 watts x 1 channel @ 4 ohm
• 150 watts x 4 channel + 500 watts x 1 channel @ 2 ohm
• Bridged: 300 watts x 2 channel @ 4 ohm + 500 watts x 1 channel @ 2 ohm
• Total RMS Power: 1100 watts
• Class D 2 ohm Stable 5-Channel Amplifier

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

VIP Product Get $47.90 in rewards to spend later

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

List price $759.00
-37% $479.00

Available

Ships in 10-14 days

Add to Cart
Limited time!

Hertz Venezia V5C Compact

1010W RMS Venezia Series Class-D 5-Channel Marine Amplifier

VENEZIA V5C big
Go to item page Right Arrow Icon of Right Arrow

Hertz Venezia V5C Compact

1010W RMS Venezia Series Class-D 5-Channel Marine Amplifier

• 5 Channel: 80 watts x 4 channel + 330 watts x 1 channel (at 4 ohms)
• 5 Channel: 115 watts x 4 channel + 550 watts x 1 channel (at 4 ohms)
• 3 Channel: 230 watts x 2 channel + 330 watts x 1 channel (at 4 ohms)
• 3 Channel: 230 watts x 2 channel (at 4 ohms) + 550 watts x 1 channel (at 2 ohms)
• Total RMS Power: 1010 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 $80.00 in rewards to spend later

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

List price $920.00
-13% $799.99

Available

Ships in 10-14 days

Add to Cart

• 5 Channel: 80 watts x 4 channel + 330 watts x 1 channel (at 4 ohms)
• 5 Channel: 115 watts x 4 channel + 550 watts x 1 channel (at 4 ohms)
• 3 Channel: 230 watts x 2 channel + 330 watts x 1 channel (at 4 ohms)
• 3 Channel: 230 watts x 2 channel (at 4 ohms) + 550 watts x 1 channel (at 2 ohms)
• Total RMS Power: 1010 watts
• Class D 2 ohm Stable 5-Channel Amplifier

Limited time!

DS18 SMD-200.4AB

800W RMS Class AB SMD Series 4 Channel Car Amplifier with Bass Remote

SMD-200.4AB big
Go to item page Right Arrow Icon of Right Arrow

DS18 SMD-200.4AB

800W RMS Class AB SMD Series 4 Channel Car Amplifier with Bass Remote

• 150 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 A/B 2 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 $45.00 in rewards to spend later

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

$449.95

In stock.

Add to Cart
Available Deal
SMD-200.4AB main
Offer may end without notice
Continue Shopping Continue to checkout
Eligible items

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

NVX XKIT44

NVX XKIT44

$119.99

$83.99

$36 Savings!

Add to cart

MTX Thunder TH900.6

900W RMS Class D Thunder Series 6 Channel Car Amplifier

TH9006 big
Go to item page Right Arrow Icon of Right Arrow

MTX Thunder TH900.6

900W RMS Class D Thunder Series 6 Channel Car Amplifier

• 75 watts x 6 channel @ 4 ohm
• 150 watts x 6 channel @ 2 ohm
• Bridged: 300 watts x 3 channel @ 4 ohm
• Total RMS Power: 900 watts
• Class D 1 ohm Stable 6-Channel-Channel Amplifier

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

VIP Product Get $75.00 in rewards to spend later

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

List price $829.99
-10% $749.99

Available

Ships in 10-14 days

Add to Cart
Continue to cart
Available Offers (2) for MTX Thunder TH900.6
FREE NVX Amp Kit at Checkout!
Add both to cart
Save 30% off an NVX XKIT46 Amp Kit at Checkout! Add a qualifying amplifier to your cart and save 30% on the NVX XKIT46 Amp Kit! No code needed — discount applies automatically at checkout.
Select your other item

Cerwin-Vega XED3002D

250W Peak (240W RMS) Class D XED Series 2 Channel Car Amplifier

XED3002D big
Go to item page Right Arrow Icon of Right Arrow

Cerwin-Vega XED3002D

250W Peak (240W RMS) Class D XED Series 2 Channel Car Amplifier

• 80 watts x 2 channel @ 4 ohm
• 120 watts x 2 channel @ 2 ohm
• Bridged: 220 watts x 1 channel @ 4 ohm
• Total RMS Power: 240 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 $14.00 in rewards to spend later

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

List price $167.99
-17% $139.99

In stock.

Add to Cart
Continue to cart
Available Offers (2) for Cerwin-Vega XED3002D
FREE Belva Amp Kit at Checkout!
Add both to cart
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.
Select your other item
See all 5 special offers

MTX Thunder TH800.4

800W RMS Class D Thunder Series 4 Channel Car Amplifier

TH8004 big
Go to item page Right Arrow Icon of Right Arrow

MTX Thunder TH800.4

800W RMS Class D Thunder Series 4 Channel Car Amplifier

• 100 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-Channel Amplifier

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

VIP Product Get $60.00 in rewards to spend later

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

List price $649.95
-8% $599.95

In stock

Only 1 Left!

Add to Cart
Continue to cart
Available Offers (2) for MTX Thunder TH800.4
FREE NVX Amp Kit at Checkout!
Add both to cart
Save 30% off an NVX XKIT44 Amp Kit at Checkout! Add a qualifying amplifier to your cart and save 30% on the NVX XKIT44 Amp Kit! No code needed — discount applies automatically at checkout.
Select your other item

Wet Sounds SYN-DX6

1400W Peak Class D SYN-DX Series 6 Channel Marine Amplifier

SYN-DX 6 big
Go to item page Right Arrow Icon of Right Arrow

Wet Sounds SYN-DX6

1400W Peak Class D SYN-DX Series 6 Channel Marine Amplifier

• 125 watts x 4 channel + 150 watts x 2 channel @ 4 ohm
• 200 watts x 4 channel + 300 watts x 2 channel @ 2 ohm
• Bridged: 400 watts x 2 channel + 600 watts x 1 channel @ 4 ohm
• Total RMS Power:
• 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 $150.00 in rewards to spend later

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

$1,499.99

In stock

Only 1 Left!

Add to Cart

• 125 watts x 4 channel + 150 watts x 2 channel @ 4 ohm
• 200 watts x 4 channel + 300 watts x 2 channel @ 2 ohm
• Bridged: 400 watts x 2 channel + 600 watts x 1 channel @ 4 ohm
• Total RMS Power:
• Class D 2 ohm Stable 6-Channel Marine Amplifier

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

Wet Sounds STX MICRO-4

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

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

Add to Cart
Limited time!

Deaf Bonce Avatar ABR-200.2

200W RMS Class AB Buran Series 2 Channel Car Amplifier

ABR-200.2 big
Go to item page Right Arrow Icon of Right Arrow

Deaf Bonce Avatar ABR-200.2

200W RMS Class AB Buran Series 2 Channel Car Amplifier

• 80 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 A/B 2 ohm Stable 2-Channel Amplifier

Save 30% off an NVX XKIT82 Amp Kit 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

$89.90

In stock

Only 2 Left!

Add to Cart
Available Deal
ABR-200.2 main
Offer may end without notice
Continue Shopping Continue to checkout
Eligible items

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

NVX XKIT82

NVX XKIT82

$79.99

$55.99

$24 Savings!

Add to cart
See all 5 special offers

DS18 G700.2D

700W Peak (360W RMS) Class D Gen-X Series 2 Channel Full Range Car Amplifier

G700.2D big
Go to item page Right Arrow Icon of Right Arrow

DS18 G700.2D

700W Peak (360W RMS) Class D Gen-X Series 2 Channel Full Range Car Amplifier

• 100 watts x 2 channel @ 4 ohm
• 180 watts x 2 channel @ 2 ohm
• Bridged: 360 watts x 1 channel @ 4 ohm
• Total RMS Power: 360 watts
• Class D 2 ohm Stable 2-Channel Amplifier

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

VIP Product Get $15.59 in rewards to spend later

Universal Icon Universal – fits most vehicles.

Shop similar products or Update vehicle

List price $187.99
-17% $155.95

In stock.

Add to Cart
Prev 14 15 16 17 18 Next

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 2005 Fortwo

    Q: Can I upgrade or change the Multi-channel Amplifiers for Adding Speakers in 2005 Smart Fortwo?

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

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

    2005 Smart Fortwo

    1984 Ford EXP

    1979 Chevrolet Nova

    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

    Cancel

    This category was not designed for products.
    If you continue, you will be redirected to a category customized for your vehicle. Continue

    Cancel

    Shop your 2005 Fortwo
    Why Use a Vehicle Fit Guide?
    Change vehicle | Shop without vehicle
    Whoa! Slow down. Add your details below!
    additional information required
    Add vehicle details to confirm fitment
    Ignore fitment details
    Find stereos and more that work -- fast.
    Remove

    Can't find your vehicle? Click here and we'll help.

    Where to find vehicle info

    Go to Fitment

    Didn't find your car?

    Submit your details and we'll help!
    Please enter the letters as they are shown in the image above. Letters are not case-sensitive.
    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
    Back

    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.

    Back
    Track your order
    Call our experts
    Support Center
    Return & Exchanges
    Follow on Instagram Instagram logo
    Subscribe on YouTube YouTube logo