Anthem MRX 740 & 1140 AV Receivers Comparison Bench Test Results!

I put the latest generation of Anthem AV receivers, namely the MRX 740 and MRX 1140 models through my bench tests in this report. The MRX740 retails for $2,899 and has 11 channels of processing with 7 channels of amplification while the MRX1140 retails for $4,000 and has 15 channels of processing and 11 channels of amplification. If you're looking for how the preouts are on these units, I've got you covered. I did a full barrage of power measurements and show the measurable differences between the two models. We discuss bass management, the best settings for optimal performance and the amplifier matrix function.

Feature Differences between the Anthem MRX 740 vs 1140

• Processing: MRX 1140 has 15 channels; MRX 740 only has 11 channels
  
• Internal Amplification: MRX 1140 has 11CH internal amplification (140wpc x 5, 60wpc x 6); MRX 740 has 7CH of internal amplification (140wpc x 5, 60wpc x2)
• Sub Outs: MRX 1140 has dual independent sub outs; MRX 740 has dual, non-independent sub outs
  
• Power Supply: MRX 1140 has a Torodial transformer; MRX 740 uses an E-Core transformer
  

All measurements were conducted using our Audio Precision APx585 8 Channel HDMI Audio Analyzer.  I go back and forth between the MRX740 and MRX1140 measurements since I tested both units simultaneously. I only show both model testing for results that displayed measurable differences.

For more information about how we measure power amplifiers, please see: Basic Amplifier Measurement Techniques

Anthem MRX 740 & MRX 1140 Preamplifier Measurements

HDMI Input -> Multi-CH Preouts

The MRX740/1140 AV receivers are capable of > 5Vrms unclipped from the multi-ch preamp outputs which is more than 2X voltage drive needed to make most external amplifiers reach full unclipped power.

 

Anthem MRX740 Preamp Output Voltage vs Distortion

The Anthem AVRs have some excellent output drive from the preouts. The distortion is vanishingly low at <0.0006% THD+N or 105dB SINAD for ASR enthusiasts. With 7CH driven, the preamp produced 5.48Vrms at 0.1% THD+N. These receivers have some serious preamp sections built into them.

Anthem MRX740 Preamp Out FFT Distortion Analysis @ 2Vrms

The Anthem MRX740 preamp output section is one of the best I’ve ever measured in an AV receiver. This can be seen by the 3^rd harmonic distortion down 108dB below the fundamental 2Vrms output drive at 1kHz. The noise floor is excellent and the power supply hum is down in the mud at -116dB. Excellent!

 

Anthem MRX740 Preamp Frequency Response

The Anthem MRX740/1140 preout is wideband with the -3dBpt > 70kHz.

 

Anthem MRX740 (2Vrms) – Dynamic Range Test (1kHz, A-wt)

It’s no surprise that the preamp outputs of these Anthem receivers are quiet. 110dB SNR @ 2Vrms with a 0dBFs input signal is excellent and among the best I’ve measured.

Note: Ignore CH3 which is the subwoofer channel.

 

Anthem MRX740 CH to CH Crosstalk Preamp Outputs

With one channel undriven and the other channels driven, channel to channel crosstalk was excellent at 95dB CH-CH isolation at 1kHz and >70dB isolation at 20kHz. Anything > 60dB at 20kHz is what I consider to be sufficient for excellent stereo separation and minimal audible channel leakage.

Analog Inputs -> Multi-CH Preouts

The Anthem AV receivers do NOT have an analog bypass mode meaning your analog signals will be digitized. In some AVR’s I’ve found they used mediocre ADC’s which could result in higher noise and distortion.

 

Anthem MRX1140 Frequency Response (analog input)

I was pleased to see Anthem employ some pretty good ADC’s with 96kHz sampling rate allowing for full bandwidth frequency response of 50kHz. Distortion was also commendably low (<0.01% THD+N @ 20kHz).

 

Anthem MRX1140 SNR (Analog Input)

With 1Vrms input and 2Vrms output, I measured 94dB SNR A-wt which is a good, quiet result though not as stellar as their fabulous STR Preamp (106dB). Don’t fear the lack of analog bypass for your analog sources. You can do them justice here but for the absolute best sound, the digital inputs are the way to go. On a separate note, if you want a phono stage and analog bypass, you'll have to step up to their AVM70 processor.

Anthem MRX 740 & MRX 1140 Bass Management

 

Anthem MRX740/1140 “Super Sub Fronts” Bass Management

“Super Sub Fronts” is Anthem’s nomenclature for enabling the subwoofer for 2CH music when your mains are set to fullrange. IF you don’t set the mains crossover, the sub will by default will have a 40Hz LPF engaged when listening to 2CH music. I recommend setting the mains crossover to your desired frequency (usually 80Hz) and then engaging “Super Sub Fronts” IF you want your mains to still play fullrange bass while simultaneously having your subs play with your desired crossover setting. The graph above depicts exactly this with the blue trace showing the default crossover off setting of the mains engaging a LPF of 40Hz for the sub out and the green trace showing the response based on the 80Hz crossover I set the mains to. The purple trace is the L/R mains playing fullrange with “Super Sub Fronts” engaged.

Anthem MRX740/1140 Bass Management Frequency Response

The Anthem MRX740/1140 bass management engaged with a crossover point of 80Hz resulted in the expected 12dB/oct HPF response for bass managed speakers but only 12dB/oct instead of 24dB/oct LPF on the sub out that we’ve come to expect in today’s modern AVRs. I asked Anthem if they could look at offering a steeper 24dB/oct crossover point and within a couple of weeks of my request, they sent me beta firmware to test.

 

Anthem MRX1140 Bass Management for Beta Firmware

Alas, now we have perfect slopes. The LPF is 24dB/oct with -6dB pt at the crossover frequency of 80Hz that I selected. Bravo!  I recommend updating your firmware to take advantage of this enhanced function. Note, I also checked the “Super Sub Fronts” mode and it worked as expected.

Anthem MRX 740 & MRX 1140 Power Measurements

Using our Audio Precision APx585 8-channel HDMI analyzer, we conducted a full barrage of multi-channel amplifier tests on Anthem MRX740 & 1140 per our Amplifier Measurement Protocol. We tested power using three methods all of which were taken at < 0.1% THD + N:

• Continuous Full Power Bandwidth (CFP-BW) from 20Hz to 20kHz into 8 and 4-ohm loads (up to two-channels)
• 1kHz Power Sweep vs. Distortion (1kHz PSweep) - popularized by the print magazines, this is an instantaneous power vs. distortion test at 1kHz. The problem with this test is it often masks slew-related and/or frequency response problems some amplifiers exhibit at the frequency extremes, and thus inflates the measured power results. It does provide an instant gratification number for consumers to argue over on the forums, so we are now incorporating this test to please the masses.
• Dynamic PWR - 1kHz CEA-2006 Burst Method testing. This is a dynamic power measurement adopted from the car industry similar to IHF method only a bit more difficult for an amplifier and more representative of real musical content.

Keep in mind most review publications don't do continuous full bandwidth power measurements and they usually publish power measurements at 1kHz into clipping at 1% THD + N. Our measurements are very conservative as we use a dedicated 20A line with no Variac to regulate line voltage.  We constantly monitor the line to ensure it never drops more than 2Vrms from nominal, which in our case was 120Vrms. 

For more info on amplifier measurements, see:  The All Channels Driven (ACD) Test

Note: Unless otherwise noted, the following amplifier test results are for the linear AB 140 watt/ch rated amplifiers of the MRX 740 and MRX 1140 AV receivers, respectively.

 

Anthem MRX740 CFP-BW (2CH) Power Test - 8 ohms

With one-channel driven, the 140 watt/ch rated MRX740 delivered 145 watts/ch for full bandwidth 20Hz to 20kHz at < 0.1% THD and about 130wpc for 2CH driven for 8 ohm loads. The MRX1140 was slightly more powerful delivering 153 watts/ch for 2CH driven at 8 ohms < 0.1% THD+N. The MRX1140 able to deliver 203wpc, 2CH driven into 4 ohms momentarily but within a few hundred milliseconds it was current limited to 163wpc, 2CH driven at 4 ohms.

 

Anthem MRX740 1kHz ACD (5CH) Power Test - 8 ohms

The MRX740 was able to deliver 89.3 watts/ch at 1% THD and 85 watts/ch at 0.1% THD with 5CH driven from its Class AB amplifiers configured for the bed channels. We see about 86dB SINAD (.005% THD+N) from the amp section at 30 watts/ch which is a very good distortion result.

 

Anthem MRX1140 1kHz (2CH, 4 ohms) Power Test

The MRX1140 doesn’t produce much more power into 4 ohm loads (176 watts/ch @ 1% THD+N) than it did into 8 ohm loads (166 watts/ch @ 1% THD+N).  There is some current limiting going on here to protect the amplifiers similar to what we see on competing AV receivers with the dreaded impedance switch. At least this doesn’t hinder power with all channels driven into 8-ohm loads like we see with some AVRs when setting the impedance switch to 4-ohms. SINAD drops about 10dB (though still not bad at 75dB) when the amps are driven to their limits into 4 ohm loads.

 

Anthem MRX740 FFT @ 1 watt, 8 ohms

 

Anthem MRX1140 FFT @ 1 watt, 8 ohms

I do FFTs at 1 watt to show how clean an amp will be at low power levels where problems could be more audible and not masked by a louder SPL. The MRX740 shows some higher power supply harmonics (-72dB) compared to the MRX1140 (-88dB). This is inaudible but academic and perhaps shows favor to why Anthem is using a torodial power supply in the MRX1140 with an E-Core in the MRX740. The 3^rd order harmonic is 90dB below the 1kHz fundamental which is a good measurement.

Anthem MRX1140 CEA 2006 Power Burst Tests (2CH, 4 ohms, 1% THD+N)

The Anthem MRX1140 produced 187 watts/ch with 2CH driven, 8-ohms and 312 watts/ch with 2CH driven, 4-ohms at 1% THD+N for our CEA-2006 dynamic burst tests. These results demonstrate good headroom on these amps to handle music/movie transients.

Anthem MRX 740 & MRX 1140 Class D Amp Section for Height Channels

I tested the Class D amp sections separately from the linear AB amps for the Anthem receivers. The power output of the MRX740 and 1140 amplifier sections are rated identically and I found this to be the case for the Class D sections with slight variances for the AB amp sections as noted in this report and associated data table. In efforts of simplicity, I only show graphical differences with the remaining data in the power table below.

 

Anthem MRX1140 Power Bandwidth 2CH, 8 ohms for Class D Amp Section

I was a bit puzzled by the bandwidth limited frequency response of the Class D amp section in these Anthem receivers despite setting them for full range for these tests. I found the -3dB pt to be 20Hz and 17kHz, respectively. This should still be fine if used as height channel duty.

 

Anthem MRX740 1kHz ACD (4CH) Power Test - 8 ohms for Class D Amp Section

The MRX740/1140 Class D amp section hit its rated 60 watts/ch power by a safe margin, capable of delivering 70 watts/ch for 2CH driven and 60 watts/ch with 4CH driven at 1% THD+N for 8-ohm loads. I did NOT test this amp section into 4-ohm loads and I’d advise using the Class D amp sections for Atmos height speaker duties or Zone 2 and NOT rerouting the amps for biamping the front channels.

 

Anthem MRX1140 FFT @ 1 watt, 8 ohms for Class D Amp section

This amp was a bit tricky to measure since its switching frequency is within the bandwidth of my test gear and I had to compensate by disabling auto-range as I initially thought it was a much nosier amp than shown here. The harmonics are 101dB below the fundamental which is excellent. A small amount of power supply hum is present but down -80dB, non-issue.

 

Anthem MRX1140 CEA-2006 Burst Test (2CH, 8 ohms, 10% THD+N) for Class D Amp Section

The Class D amp section of the Anthem AV receivers shows some good dynamic headroom (+2.2dB) on the 60 watts/ch rated amplifiers.

Anthem MRX740 & MRX 1140 Power Measurements Summary

# of CH	Test Type	Power	Load	THD + N
1	CFP-BW	145 watts	8 ohms	0.1%
2	CFP-BW	130 watts	8-ohms	0.1%
2	1kHz Psweep	144 watts	8-ohms	1%
2	1kHz Psweep	131 watts	8-ohms	0.1%
2	1kHz Psweep	180 watts*	4-ohms	1%
2	1kHz Psweep	180 watts*	4-ohms	0.1%
5	1kHz Psweep	89 watts	8-ohms	1%
5	1kHz Psweep	85 watts	8-ohms	0.1%
2	Dynamic PWR	212 watts	8-ohms	1%
5	Dynamic PWR	180 watts	8-ohms	1%

Anthem MRX740 Power Measurement Table

# of CH	Test Type	Power	Load	THD + N
2	CFP-BW	153 watts	8 ohms	0.1%
2	CFP-BW	203 watts*	4-ohms	0.1%
2	1kHz Psweep	163 watts	8-ohms	1%
2	1kHz Psweep	155 watts	8-ohms	0.1%
2	1kHz Psweep	176 watts*	4-ohms	1%
2	1kHz Psweep	174 watts*	4-ohms	0.1%
2	Dynamic PWR	187 watts	8-ohms	1%
2	Dynamic PWR	312 watts	4-ohms	1%

Anthem MRX1140 Power Measurement Table

# of CH	Test Type	Power	Load	THD + N
2	CFP-BW	60 watts	8 ohms	0.1%
2	1kHz Psweep	70 watts	8-ohms	1%
2	1kHz Psweep	65 watts	8-ohms	0.1%
4	1kHz Psweep	60 watts	8-ohms	1%
4	1kHz Psweep	54 watts	8-ohms	0.1%
2	Dynamic PWR	103 watts	8-ohms	10%

Anthem MRX740/1140 Power Measurement Table for Class D Amps

 

Anthem MRX740 CH-CH Crosstalk (1CH, Undriven) @ 1 watt

The channel-channel crosstalk was good for a multi-ch AV receiver. With ACD except for the one under test, the MRX740 provided > -50dB of CH-CH isolation at 20kHz.

Anthem MRX 740 & MRX 1140 Amplifier Matrix

 

Anthem Amplifier Matrix per Web Interface

The Anthem MRX740 and MRX1140 both have the ability to reassign the amplifier sections. The options are tabulated below as of Firmware ver: 1.106.157 loaded into my units.

• Front – Front, Zone2, Front Wide, Height 3
• Surround – Surround, Zone2, Height 3
• Back – Back, Zone2, Front Wide, Front Biamp
• Height1 – Height 1, Zone2, Front Biamp
• Height2 – Height 2, Zone2, Front Wide, Front Biamp

As I indicated in this test report, I do NOT recommend EVER assigning the Class D internal amps in these AVRs for bi-amping the front channels. It is my recommendation that Anthem removes this option. The Class D amps are fine for height or Zone 2 duties. But using them in bi-amp mode for your front speakers means there will be a 3.7dB penalty in dynamic range. It would make more sense if the Front and Surround Channels could be reassigned as Height 1, 2 or 3 that way a user could purchase one of Anthem’s excellent 5CH amps to power the bed channels and use the internal Class AB amps to power the height channels. Then they could use the Class D amps to power Zone 2 or Front wides.

Conclusion

The Anthem MRX740 and MRX1140 AV receivers have world class processing and internal preamplifiers. They are extremely low noise and have plenty of drive to work optimally for any home theater or audiophile amplifiers you’d like to use with them. One could easily make the argument for picking up one of these units instead of spending more on a dedicated Pre/Pro and just adding external amplification to better power more demanding low impedance speakers. In fact, I will make such an argument that the MRX740 is one of the best 11CH AV processors currently on the market and the MRX1140 for 15CH of processing. The MRX1140 has a slight advantage in a better power supply IF you’re using the internal amplifiers as well as dual independent subwoofer outputs and more channels of processing with two more channels of amplification.

While these AV receivers aren’t the most powerful in their respective price classes, they offer commendably good amplifier performance if paired with loudspeakers with a nominal impedance of 6 ohms or higher. I am looking forward to testing out the latest iteration of Anthem’s ARC Genesis, which is among the best room correction, and user friendly software options out there. Stay tuned for the full review as we integrate the MRX1140 AVR into the AH Smarthome 5.2.2 master bedroom system featuring the Klipsch Heritage passive Soundbar and dual 8” in-ceiling JL Audio subwoofers.

Unless otherwise indicated, this is a preview article for the featured product. A formal review may or may not follow in the future.