My system has plenty of power. Who needs an amp?

You might think you don't need an amp because you have a 400-watt system in your car, or because your new stereo puts out 50 watts a channel. But those are peak wattage ratings, which may boil down to 15 or 20 watts per channel, using the more realistic RMS rating. An amp sends your speakers the power they need to deliver your music with clarity and impact, whether you're using factory speakers or high-performance components. And low-frequency reproduction requires lots of power, so an amp is an absolute must if you're adding a sub to your system.

Our take on the Sony XM-GS100

by Buck Pomerantz

Brings you the bass

You'll get up to 600 watts RMS of bass power with Sony's XM-GS100 mono amplifier driving your sub. For maximum reliability, this compact amp sports a hefty heatsink that shunts off the heat that's generated when the amp's working hard. The XM-GS100 will also protect your subwoofer, with a Dynamic Distortion Suppressor circuit that rounds off the corners of dangerous square waves, minimizing the destructive effects of an overdriven signal.

More features

All connections are located on one side of the amp, which makes wiring simpler and neater. The tuning controls sit protected under a cover so they won't get inadvertently moved. You'll find a low-pass filter for keeping high notes away, along with a subsonic filter that helps tune your bass for a ported enclosure so the lowest notes don't get out of control. You can crank up the variable bass boost if you need some more bump. Sony protects this amp with a 3-year warranty, and that says a lot.

See more info on this item

Highlights:

mono subwoofer amplifier
330 watts RMS x 1 at 4 ohms (600 watts RMS x 1 at 2 ohms)
CEA-2006 compliant
Dynamic Distortion Suppressor and Active Thermal Control
variable low-pass filter (50-300 Hz, 12 dB/octave)
variable subsonic filter (6-70 Hz, 12 dB/octave)
variable bass boost (0-10 dB at 40Hz)
Class-D amplifier design
frequency response: 10-300 Hz
preamp and speaker-level inputs
preamp outputs
fuse rating: 30A x 2
4-gauge power and ground leads recommended — wiring and hardware not included with amplifier
10-3/4"W x 2-1/8"H x 8"D
warranty: 3 years
Our 60-day money-back guarantee

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Hands-on research from the Crutchfield Labs (what are the Labs?)

Features and specs chart | What’s in the box? | In-depth notes

Features and Specs

Performance
RMS Power Output (Watts x Channels) Loading...	330 x 1
Peak Power Output (Watts x Channels) Loading...	1100 x 1
Power at 2 Ohms (Watts x Channels) Loading...	600 x 1
Bridged Power (Watts x Channels) Loading...	N/A
Minimum Impedance Bridged Loading...	N/A
Minimum Impedance Unbridged Loading...	2
Best Frequency Response Loading...	10-300 Hz
THD at Rated RMS Power Loading...	1%
Signal to Noise Ratio Loading...	65 dB
Input Voltage Loading...	14.4v
Features
Amplifier Class Loading...	D
Low-Pass Crossover Frequency Loading...	50-300 Hz
Low-Pass Slope (dB/octave) Loading...	12 dB/octave
High-Pass Crossover Frequency Loading...	N/A
High-Pass Slope (dB/octave) Loading...	N/A
Bass Boost Loading...	0-10 dB
Bass Boost Frequency Loading...	40 Hz
Fan Cooled Loading...	No
Fuse Rating Loading...	60
Speaker Level Inputs Loading...	Harness
Preamp Outputs Loading...	1 pair
Width (inches) Loading...	10-3/4
Height (inches) Loading...	2-1/8
Depth (inches) Loading...	8
Parts Warranty Loading...	3 Year
Labor Warranty Loading...	3 Year

Product Research

What's in the box?

Download owner's manual

Mono amplifier
4" Speaker level input harness
Two 30 amp ATO fuses (installed)
Four 1/2" Self-tapping screws
Operating instructions (English/ French/ Spanish)
Warranty information

Our Product Research Team

At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team — they open the box, verify contents, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.

Features

Crossover: The low pass crossover is always engaged (cannot be bypassed); the crossover point is continuously variable from 50 to 300 Hz.

Subsonic Filter: The subsonic filter's cutoff frequency is continuously variable from 6 to 70 Hz.

Bass Boost: For added low frequency output, the amplifier has bass boost circuits centered at 40 Hz, variable from 0 to +10 dB.

Protection Circuitry: The amp has three protection circuits:

Thermal: turns the amp off when the operating temperature is too high
Short circuit: turns the amp off when the speaker outputs are short-circuited
DC Offset: turns the amp off when it generates direct current

Power/Ground Terminals: The power and ground screw terminals are 0.55" wide.

Remote Terminal: The remote turn on screw terminal is 0.36" wide.

Speaker Outputs: There are two pair of speaker output screw terminals, internally shorted together so it's easy to connect two subwoofers. Each terminal is 0.36" wide.

Speaker-level Input Harness: A 4-pin speaker level input harness is included, allowing you to easily connect the amplifier to a factory radio or a receiver without preamp outputs.

Auto Turn-on: When using the speaker level inputs, the amp will automatically turn on when it senses an input signal.

Preamp Outputs: The amplifier features one set of RCA preamp outputs so you can send audio to another amplifier in your system. The preamp outputs are not affected by the built-in crossover.

Note: The preamp outputs are not active when the speaker level input is used.

Product reviews from the Crutchfield Labs (what are the Labs?)

Video: Sony GS Car Amplifiers

Video Guest

10/5/2012

Sony's efficient GS car amplifiers give you clean, effective power to make your car audio system sing. There are two GS models: a 4-channel, and a mono subwoofer amp. Both feature RCA and...

Quick impressions from the Lab

Written by Buck Pomerantz, Staff Writer - Creative, on 8/17/2012 5:05:00 PM

The first thing I noticed was the nice heft of the amp — it's pretty heavy for something with a footprint smaller than a piece of letter-size paper. Over half its chassis is heavy heatsink. All the connections are on one side, and they appear to be gold-plated. The adjustment controls are under a cover, which is removable with a Phillips-head screwdriver.

The instructions aren't in a bound owner's manual, but on a large fold-out sheet of paper. Make sure you read them carefully, they can be a little difficult to follow. However, the explanation of the Dynamic Distortion Suppressor feature clearly diagrams how it smooths the corners of square waves to lessen the distortion effects of over-driving the signal.