Kudos: Full-featured AVR performance in a small footprint; ARC room correction
Concerns: Wish app showed incoming signal format
Usually, the products I choose to review are all about bigger and better. Send me the biggest TV! Send me the largest speakers! Of course I’ll take the dual-sub system!
But when Anthem sent me its new MRX SLM for a First Look Unboxing video, I was really impressed with how much technology and performance they packed into such a small package. And after speaking with Kyle Delnero, director of training, support, & Eastern U.S. sales for Paradigm and Anthem, it was clear how many problems the SLM could solve and the cool solutions it could fill.
The MRX SLM is the quintessential example of big things coming in small packages. At just 1U high and 11 inches wide and deep (technically 13 inches deep with the power cord), the MRX SLM can fit into spaces other AVRs couldn’t even dream of, without sacrificing any bells and whistles. And with the included mounting bracket, you can get creative — say, mounting it to the side of a cabinet, underneath a shelf, or flat to the back for a depth of just 1.5 inches!
Why You Should Care
The Anthem MRX SLM is a problem-solver, plain and simple. Ever show up to a job and the cabinetmaker did you dirty? What was supposed to be 18-or-more inches of depth turns out to be more like 14 or less? Or they put a divider right in the middle of your space and now you are down to 12 inches of width? Or when you’re working on a boat or RV system where space is at an absolute premium and you have got literally a nook and cranny to work with? Or if you have got literally nowhere to place the electronics short of behind the display in a VersaBox or mounted under a desk? Or if the job scope expands and you find yourself running out of real estate in your rack?
These are all cases where the MRX SLM will be your “Get-Out-of-Jail-Free” card, letting you be the hero by turning an “I’m sorry we can’t” into an “I’ve got the perfect solution for this!”
And don’t let the size fool you; the MRX SLM is a full-featured AVR, packing in the build quality and virtually every feature and configuration option that you’d expect from its bigger Anthem brothers.
So, why should you care? If you have got a project that is using a 5.1-channel speaker system where space is limited but high performance and full system integration is still expected, the Anthem MRX SLM is on the shortest-of-lists of products that can fit the bill.
First Impressions
From the jump, one of the very first things you see when opening the box is the ARC (Anthem Room Correction) microphone. This, as much as anything, told me that this was a fully engineered Anthem product and not just some compact solution churned out at the expense of performance. ARC is one of the highest regarded forms of room correction and offers a ton of configuration to squeeze the most performance out of any system in a given room. The SLM uses ARC Genesis, the latest and most advanced room correction offered by Anthem. (You can read more about ARC at www.anthemarc.com.)
Along with the ARC microphone, included is an IR remote control, detachable power cord, IR target, USB cable for the mic, two Wi-Fi and Bluetooth antennas, and the mounting bracket.
Pulling the SLM from the box, it just feels solid. It has a metal chassis and a brushed aluminum top panel with ANTHEM screened into it, and nothing feels cheap or plastic. Honestly, I had to read the published weight (6.6 pounds) a few times just because I didn’t believe it. Anthem also offers a nice optional faceplate with laser-engraved logos if you’re going to be rack-mounting it.
The second notable thing is that the SLM has no front-panel controls. As in, none. No power, no volume, no anything. Other than some logos, there is just a single power LED that illuminates blue when on and can blink to show if it is in Bluetooth pairing or Wi-Fi setup mode. To save on space, Anthem has stripped away anything that isn’t vital, and as the SLM is meant to be tucked away out of sight, any controls or displays would be superfluous.
Spinning the unit around, you see that virtually every inch has been utilized to full effect, and that the SLM will support just about any scenario you’d realistically throw at it.
There is a detachable Phoenix connector block for five speakers and an RCA subwoofer output to cover your 5.1-channel speaker connections. For sources, the SLM offers an HDMI input and HDMI output with eARC, as well as mini-jack analog audio and Toslink optical digital audio inputs. It also has a chassis ground connection if you’re wiring in a turntable or have any ground-hum issues. Between these four connections, you have got the ability to connect a local HDMI source directly to the SLM, get all of the audio from anything connected to the display, and enjoy a legacy analog and digital audio source.
The HDMI input is 2.0b, which supports HDR including Dolby Vision and resolutions up to 4K/60, but not 4K/120 or VRR, so if you’re connecting a gaming console like a PS5 or Xbox X, you’d want to connect that directly to the display. Fortunately, the eARC connection fully supports all next-gen audio formats like Dolby Atmos and DTS:X.
Theres’s also a wired Ethernet connection, USB-A for updates, and a mini-jack input if using the included IR extender. For the record, the SLM’s front panel receives IR signals without the extender just fine, and the IR extender is only required if it is being installed out of sight. So, basically like any other receiver, except Anthem did you the solid of including an IR target. You’re welcome. The rear panel also includes a pinhole button that can be used for a quick DHCP reset (short press) or a full factory reset (long press).
Any time that a product gets you excited and starts the wheels in your mind turning about all of the cool things it can be used for, that’s a good thing, so it’s safe to say that my first impression of the SLM was very positive!
Setup
Once you’ve made your connections, the SLM is basically good-to-go. You can use the remote to select an input and then start listening. However, as with any AVR, maximizing its performance and features requires some configuration and calibration. This can be done either via the Anthem Remote App (iOS and Android) or web GUI.
If you’ve connected the SLM to your network with an Ethernet cable, you’re ready to start, but if you’re going with Wi-Fi, you’ll first have to connect the SLM to the local network. If using an iOS device, you’ll set it up as a new AirPlay speaker, which I did with no issues, automatically grabbing my network’s Wi-Fi settings from my iPhone. If you have Android, you’ll set it up as a “Google Nest or partner” device. If you have issues with any of those methods, you can also temporarily hardwire the SLM to your network, and then go into the Network and Wi-Fi configuration in the web GUI. (You can get the SLM’s IP address using the Anthem Remote app.)
Once connected, you can access the settings from either the app or web, and here you’ll get a taste of the configuration power inside the SLM. Under General, you can set an AirPlay password, adjust the LED brightness, and set the power on volume, maximum volume, and which input to go to on power-on.
You have a host of speaker setup options, including a variety of speaker layout options. While the SLM only has five channels of amplification, you have a lot of flexibility over how to use them, with the ability to process the non-LCR channels as either surround, front (Bi-Amp), front in-ceiling, front Dolby, front on-wall, middle in-ceiling, back in-ceiling, or back on-wall.
There are also four configurable profiles that can have different speaker settings, able to turn on/off the subwoofer, center, or surround channels, as well as independently set distances, channel levels, crossovers, and subwoofer settings. Why multiple profiles? Say you wanted different listening setups for 2-channel versus surround, had two different primary listening positions, or wanted to optimize sound with a projection screen up versus down, etc.
There are six inputs pre-configured out of the box: HDMI, TV (HDMI eARC), Streaming, Bluetooth, Digital (Optical), and Analog. These inputs correspond to the direct input buttons on the IR remote. You can delete any of these, add new ones, or reconfigure them. Configuration options allow you to name the input, select the video and audio input, select the listening profile, select the default audio mode it uses, select whether or not to use ARC, select Dolby and DTS settings (including whether or not to use Dolby speaker virtualizer), and adjust the lip sync and input volume trim.
Like any modern AVR, the SLM includes a variety of audio listening modes, but unlike Rock Hall or Jazz Club DSP, many of these are actually useful. You can select None, which applies no upmixing, Automatic, which will play Dolby or DTS if input and apply no upmixing if not, Last Used, AnthemLogic Cinema or Music, which upmixes stereo signals (notably, AL Music doesn’t use the center channel for “a more enhanced stereo listening experience”), Dolby Surround, DTS Neural: X, All Channel Stereo, Mono, which sums everything to just the center channel, and All Channel Mono.
You also have full configuration of the network settings, and can backup or load both user and installer settings, change default settings, perform a hard reset, or have the unit check for firmware updates.
If you are using the IR remote and placing the SLM out of sight, you’ll want to configure the IR to use the rear input (found under the network settings). You can also turn the IR input off if you want to lock out remote operation. One thing that would be nice would be if the SLM also had a mini-jack IR output so you could pass other IR commands through it to any other gear also secreted away.
Beyond the included IR remote and Anthem Remote app, the SLM can integrate with a host of third-party automation systems like Crestron, Control4, ELAN, RTI, Savant, and URC, with drivers available for download on Anthem’s site.
As I said, this is a fully functional Anthem AVR, just in a smaller package.
ARC: Anthem Room Correction
This is such a big part of the full SLM installation — or any Anthem product, for that matter — that it really begs its own section.
In Anthem’s own words, “ARC Genesis understands the acoustic characteristics of listening rooms and optimizes the audio performance of 2-channel and home theater systems to deliver the best possible performance within each unique room. It effectively tames resonances, reflective surfaces, and other obstacles that can negatively affect the sound, especially at low frequencies.”
The first step is to download the ARC Genesis software (PC or Mac). Once installed, it will bring up a home screen that gives you several options, such as to launch ARC, open a saved file, or launch a quick measure tool. Before taking any measurements, you’ll need to connect the included ARC microphone to your computer via USB cable. Since the microphone is connected directly to the computer and not the SLM, it means you can still take measurements even if the SLM is in another room or in a panel behind the display.
If you’ll be selling a lot of these — or, again, any Anthem AVRs/processors — then you’ll definitely want to invest in a decent microphone stand. I used the one that came with my Audyssey Pro kit, but you could also use the ARC Genesis Kit from a full-size Anthem MRX/AVM/STR Series product.
The quick measure tool is a nice way to get a quick snapshot of the room and check that all speakers are wired correctly and working, do a rough level match on the subwoofer, and get a sense of how the room is affecting the sound at the listening positions.
Before taking any measurements, you configure the system, telling it whether to measure in Imperial or metric, which speakers to measure, and the number of positions to measure between 5-10. Then you measure the first position, first measuring all speakers for level and EQ, and then again for relative delays, then you repeat at the other positions.
Once measurements are concluded, you can use ARC’s auto settings or optionally go and tweak the profile. Here you can adjust the system-wide target curve, adjusting the room gain dB and center frequency, deep bass boost dB and center frequency, and tilt level dB and start frequency. You can also choose the crossover frequency for each channel, whether to send lower frequencies to the subwoofer or which order crossover slope to use, set the high-frequency roll-off, and establish the maximum correction frequency. For the subwoofer, you can set the range for both high- and low-frequency extension, set a slope for low-frequency extension, set the minimum correction frequency, and set phase and phase frequency.
After you’ve uploaded the correction curves, you can also run an automatic phase adjustment tool that takes 12 additional measurements from 0–180 degrees to measure the correct phase settings between your front speakers and the subwoofer.
When finished, you get a nice multi-page color report that you can present to clients that shows the date the measurements were taken, the target, measurement, and correction curves for each speaker, and then a report of all the settings.
Start to finish, running ARC will probably take you around 10 minutes, but it really puts the bow on a finished project. Once completed, you can easily toggle the ARC settings on/off within the app for real-time A/B testing of the before-and-after results.
Performance
I took the SLM to my CI showroom where I connected it to a 5.1-channel Monitor Audio Radius bookshelf system that is probably typical of what the SLM would be driving in the real world. I also took it home, where I connected it to a 3.1-channel Definitive Technology Mythos ST tower system along with the SVS SB3000 in-wall subwoofer.
While the SLM is rated at “only” 50 watts/channel at 8 ohms, I’d say this is a conservative rating. In practice, it didn’t seem to have any issues driving either speaker system. It is also 4-ohm capable and can deliver a maximum output of 92 watts into 4 ohms. Of course, I wouldn’t recommend connecting it to an inefficient or difficult-to-drive speaker, but that’s not where the SLM is meant to live.
I watched a lot of streamed and Kaleidescape content, and the SLM always did exactly what it was supposed to. At my showroom, I got the full 5.1-channel experience, but at home with my 3.1-channel setup, I engaged the Dolby Speaker Virtualization, which is designed to give a better sense of surround sound from a stereo or 3.1-channel configuration, and I was very impressed with the results. Not only did it give more width and expansiveness across the front channels, there were several times when I looked over to the sides, convinced a speaker was there.
Toggling ARC on and off showed that the correction made subtle but noticeable improvements. With it off, bass was a bit heavy and bloated, but with ARC engaged it had more definition, clarity, and punch. This was noticeable in bombastic scenes like the opening of Underwater where the Kepler rig starts collapsing or the depth-charging scenes in U-571. It also seemed to tighten the sound from the center channel and create better cohesion across the front LCR, and overall just improved the clarity of the presentation.
For music playback, the SLM supports AirPlay, Google Cast, Spotify Connect, and Bluetooth. I mainly use AirPlay, and the SLM always appeared in my list of available devices and then played without a hitch.
The only hiccup I had with the SLM were some HDMI CEC communication issues between it and the Sony BRAVIA 8 TV at my showroom, where the TV would just randomly stop controlling the SLM’s volume. It still output the audio and I could adjust it with the SLM remote or app, but not with the TV’s volume control. Honestly, this seemed more a Sony TV issue, and I could resolve it by turning eARC on/off or cycling between the TV speaker and audio system. However, had this been a real-world install, I’d have been making a service call to change something.
If there are two tweaks I’d love to see the SLM incorporate, the first would be to have an OSD. Of course, with eARC working you get an onscreen system volume level when making adjustments, but it would be nice if there was an OSD for setup or for checking a setting. Of course, the app can be used for this, but I’m old school and like an OSD.
Second, short of an OSD, I wish the Anthem app would display the incoming signal format (Dolby, DTS, etc.). If you want to see the incoming signal format — say to confirm you’re actually getting the Atmos bitstream — you have to open a Web browser and look at the info tab. This info should definitely be displayed in the app where it would be far more accessible.
The Anthem MRX SLM is a unique product that does everything it needs to do and is supposed to do very well. If you run into an install where there just isn’t any room for a traditional AVR, or have been opting for soundbar sales because they are easier, the MRX SLM will let you sell larger, more profitable, higher-preforming systems that can be built around either an LCR speaker bar, bookshelves, or in-walls to deliver a full surround experience without compromise.
Product Specs:
- 1-channel slimline AVR with 50 watts/channel
- HDMI 2.0b/HDCP 2.3 with eARC
- Anthem Room Correction (ARC) Genesis
- Decodes Dolby (including TrueHD/Atmos) and DTS (including X)
- Wireless audio streaming via Apple AirPlay, Google Cast, Spotify Connect, and Bluetooth
- Complete control and setup via Anthem Remote App (iOS and Android)
- Robust third-party integration with IP drivers for Crestron, Control4, Savant, URC, RTI, and ELAN
- Connections: Inputs: HDMI (2.0b), Analog audio mini-jack, Toslink optical, RJ 45 Ethernet, IR mini-jack, chassis ground; Outputs: Wireless Bluetooth/Wi-Fi antennas, RCA subwoofer out, HDMI output with eARC, detachable Phoenix-type connector for 5 speakers, detachable power connection
Dimensions and Weight: 1.7 x 11 x 11 inches (HxWxD); Weight: 6.6 pounds
