When it to comes to value, five-channel car audio amplifiers are a great solution for upgrading the stereo system in your vehicle. Aside from reducing the time it takes to install, five-channel amplifiers minimize installation complexity and the cost associated with signal, power and ground connections compared to running multiple amplifiers. Sony’s Mobile ES Series XM-5ES five-channel amplifier goes under the magnifying glass in this BestCarAudio.com Test Drive Review.
Physical Features and Amplifier Connections
As with the other Mobile ES amplifiers, Sony based the XM-5ES on a custom-tooled cast aluminum chassis. The amp measures just under 15 by 8.5 inches and stands 2.36 inches tall. All connections are made along the front edge of the amp to keep the installation tidy. The amp has a removable top panel that conceals the configuration controls. Sony has also included a small plastic trim piece with the Mobile ES logo on top of the amp. Your installer can remove and rotate this component, so the logo is upright to match the layout of your system. The amp has a clean, monolithic look. Few companies can rival Sony’s industrial design talents.
Sony emphasizes that they’ve put significant effort into ensuring that the amp’s chassis is solid and secure and won’t make noises while your vehicle travels down a bumpy road. A key component in this effort is the bottom panel of the amp. The heavy-gauge stamped aluminum panel has embossed ridges that prevent vibration. You might think plexiglass bottom panels look cool, but they have the rigidity and reliability of a wet paper towel.
Sony rates the XM-5ES as capable of producing up to 100 watts from each of the four main channels and 450 watts from the subwoofer channel when driving 4-ohm loads. When driving 2-ohm loads, those numbers increase to 165 and 750 watts, respectively. The main channel pairs can be bridged to produce up to 330 watts into a single 4-ohm load. The signal-to-noise ratio is specified as -77 dBA referenced to 1 watt of output, and the total harmonic distortion is rated at 0.05% at 1 kHz with 4-ohm loads. Finally, frequency response is listed as 10 Hz to 40 kHz on the main channels and 10 to 500 Hz on the subwoofer channel with tolerances of +0.5 and -3.0 dB.
Amplifier Connections and Controls
The amp’s front panel features a large power connection block on the right side that will accept 0-AWG power and ground cables. There’s also a terminal for the remote turn-on wire from an aftermarket radio or an integration processor. Alternatively, a switch on the top panel activates an automatic turn-on circuit should your installation have this amplifier connected to a factory-installed source unit that doesn’t have a remote turn-on lead.
Four 40-amp ATC fuses are located next to the power connections. Three four-position terminal blocks handle the speaker and subwoofer connections. The speaker connections will work with bare wire but are also designed to accept ferrules. There’s a microprocessor-controlled cooling fan on the amp’s back panel to assist in cooling when the chassis gets hot.
A bank of RCA jacks on the left side of the panel accepts front, rear and subwoofer input signals. In addition, there’s a set of stereo outputs should your installer need to send audio signals to a secondary amplifier. The inputs include balanced differential circuitry to reduce noise. As such, you should choose twisted-pair interconnects for use with this amp. A switch to the left on the input jacks selects between low- and high-voltage ranges. In the low range, the amp will produce full power with inputs from 200 millivolts to 8 volts, or 3 to 16 volts in the high range. Lastly, there’s a connection for the included remote bass level control.
The amp’s top panel is home to an impressively complete set of system configuration controls. The front and rear stereo channels have separate high- and low-pass filter adjustments configurable in high-pass, low-pass or band-pass operation. The filters have -12 dB/octave slopes. A range switch allows your installer to use them in the range of 50 to 500 Hz or 500 Hz to 5 kHz, depending on the speakers in the system. Of course, each pair of channels has a dedicated input sensitivity adjustment to optimize the system.
The subwoofer channel includes an infrasonic filter that’s adjustable from five to 50 hertz and a low-pass filter with a frequency range of 50 to 500 hertz. The low-pass filter can be turned off if you wish to use one built into a source unit.
Aside from the turn-on detection selection switch, there are two switches to configure signal distribution on the input side of the amp and a third that controls where the output signal is sourced. The SUB CH switch determines if the signal for the subwoofer channel comes from inputs 5 and 6, from just input 5, inputs 1 and 2 or inputs 3 and 4. The CH 1-4 switch handles signal routing for the four main channels and allows your installer to select the 1-4 option, where each input channel feeds directly to each output. There are also options where input 1 feeds all four channels or where inputs 1 and 2 feed stereo signals to the fronts and rears. The fourth option combines the signals from inputs 1 and 3 and sends their sum to outputs 1 and 3. The same is done for inputs 2 and 4. This is a perfect solution if your installation requires combining signals from two sources. The Line Out switch has a THRU mode that feeds inputs 1 and 2 out Line Out 1 and 2. The STEREO position combines inputs 1 and 3 and feeds that to Output 1 and combines Inputs 2 and 4 and sends that signal to Output 2. Finally, the All mode combines signals from Inputs 1 through 4 and feeds that signal to both Output connections.
Removing the thick bottom plate from the amp reveals two independent power supplies – something that’s not very common on five-channel amplifiers. It’s worth noting that each supply has a pair of ceramic-core inductors on the input side to help prevent switching noise from leaking back out of the power leads. The main supply has six 2,200-microfarad, 16-volt caps on the input side, while the subwoofer supply has four identical units. There are three groups of capacitors on the outputs of the two supplies. The bank of four large, 4,700-microfarad, 50-volt caps appears to be for the subwoofer channel. The main supply, therefore, has two banks of eight 800-microfarad, 50-volt caps to store energy and smooth any ripples.
The audio processing and preamp circuitry is located on a separate control board mounted vertically closer to the bottom edge of the main board. All the switches and potentiometers for signal routing and filtering are mounted to this board. It’s worth noting that Sony tooled a stamped metal support bracket to ensure that the control board is secure and doesn’t have to rely on electrical connections for stability.
Each main output channel is driven by an International Rectifier IRS2092S digital amplifier driver IC with a pair of Toshiba N-Channel MOSFETS providing the current for the low-impedance load. The subwoofer channel uses a pair of IR drivers and has eight Toshiba MOSFETS in a full-bridged configuration. The Class D output filters on each of the five channels use magnetically shielded inductors to help keep noise out of the system.
Auditioning the Sony XM-5ES
I set the amplifier up in my listening room with channels 1 and 2 powering a set of bookshelf speakers and the subwoofer channel driving the Sony XS-W104ES 10-inch subwoofer I reviewed last year. The subwoofer’s output was adjusted so that the system matched my acoustic target curve with a tolerance of 1 dB.
The first track I played was “Blue Monday” by New Order. This track has a solid bass line with lots of impact from 50 to 150 hertz. It’s great for evaluating the dynamics of a system. The XM-5ES produced a solid punch. The vocals remained nicely focused in the center of the soundstage.
I listened to “Crash into Me” by Dave Matthews Band next. The amp reproduced the cymbals high and to the left, and the drum left of center. The vocal was also up high above the speakers. The impact from the kick drum was rich with a solid impact.
Up next was “I Can See Clearly Now” by the Holly Cole Trio. Holly’s voice was dead center of the soundstage, and the piano had a nice, realistic balance to it. The upright bass was a little tubby in the lower midrange but not to the point of being unrealistic.
Last, I decided to crank the volume and listen to “On the Floor” featuring Pitbull by Jennifer Lopez. This is one of those songs that’s better when played loudly. The deep bassline that comes in at 1:32 filled the room with energy. This track has good low-frequency extension with fundamentals down to 32 Hz. The Sony amp remained composed and didn’t get sloppy at high volumes.
Overall, the reproduction of music through the XM-5ES was clear, with very slightly attenuated high-frequency performance. I’d call this “slightly laid-back.” With that said, the balance would work well in vehicles without any signal processing. The amp didn’t make any nasty noises during power-up or while shutting down.
Bench Testing the Sony XM-5ES Five-Channel Amplifier
The first of the lab tests was an evaluation of the frequency response characteristics of the main and subwoofer channels. The main channel’s frequency response was 8 hertz to 27.2 kHz with -3 dB tolerances using the reactive simulated load. There was less than 0.2 dB variation across the audio spectrum, and the little dip at 5k shown in the reactive measurements is likely similar to what I heard in the listening room. The subwoofer channel response didn’t vary much with different load impedances. The frequency response on the subwoofer channel was exceptionally wide at less than 2 hertz on the bottom and 600 hertz on the top. That’s one of the lowest low-frequency roll-offs I’ve seen in a long time. If you’re playing music with large amounts of low-frequency energy, you’ll want to enable the infrasonic filter to protect the subwoofer from bottoming out.
Next, I tested the function of the electronic crossovers on the main and subwoofer channels. Everything seemed to function normally on the mains. On the subwoofer channel, low-frequency extension is reduced a tiny bit when the low-pass filter activated. However, this isn’t an issue, as the -3 dB point remains impressively low at just under 3 hertz.
Satisfied with the frequency and filter functionality testing, it was time to measure the noise and distortion performance of the XM-5ES. At an output level of 2.0 volts, which equates to 1 watt of power to a 4-ohm load, the harmonic distortion was predominantly second-order at a level of 0.0817%. The signal-to-noise ratio was acceptable at -67.48 dB. I performed THD+N versus frequency sweeps, and the amp remained well-behaved across the audio spectrum.
The subwoofer channel performed equally well and demonstrated slightly better numbers with a 50 hertz, 2-volt THD+N spec of 0.0246% and an SNR of -74.76 dB. The subwoofer channel didn’t show anything abnormal regarding distortion versus frequency. The rise on the right side of the graph above 1 kHz is due to the significant attenuation of the output signal in that region and is normal.
The last distortion test evaluated the intermodulation characteristics of the XM-5ES main channels. I used 19- and 20-kHz tones, the standard for the ITU-R IMD test. The product at 1 kHz was a bit higher than ideal at -58.74 dBr or 0.116%. The upper sideband was at -62 dBr, which is 0.079%.
OK, now for the overly popular power measurements. The Sony XM-5ES is an impressively powerful amplifier capable of giving four-AWG wiring a workout by drawing 120 amps of current with all channels driven into clipping. As such, don’t skimp on wiring. If you can, make the most of the 0-AWG power and ground connections and feed the amp as much voltage as possible.
The amp remained well-behaved on the bench during power testing and didn’t squeal, whine or buzz. Given the voltage drops associated with my power supplies, the XM-5ES would have had no issues exceeding its 100/165 and 450/750-watt ratings. Full-power efficiency was excellent at around 87% with 4-ohm loads and at 77% with everything wired to 2 ohms.
For my curiosity, I tested the output of the subwoofer channel into 2 ohms without the main channels running to see just how isolated the power supplies are. The only difference in output was related to the increase in voltage from my supplies. Two thumbs up on the power production!
Sony XM-5ES Summary
There are lots of five-channel amplifiers on the market these days. Finding one that makes significant amounts of power, offers good efficiency and has a well-thought-out set of features isn’t easy. The Sony XM-5ES checks all these boxes in a big way! If you want a classy-looking, well-built amplifier that will power an entire audio system with a subwoofer with authority, drop by a local authorized Sony Mobile ES retailer and ask about the XM-5ES. You can learn more about Sony car audio products by visiting their car and marine audio website. Be sure to follow Sony Car Audio USA on Facebook for the latest information on their Mobile ES solutions.