Integrated Amp Reviews

There are four different Profiles, into which you can load different speaker setups; eg, with and without a subwoofer. Since I didn't use a sub, I used only a single Profile. But the manual uses the words profile and configuration (or config) synonymously, which can be confusing. And while it also isn't made entirely clear, the same input can be configured in different ways with different names. For example, I set up two separately named configurations for Coax 1, the input I used 99% of the time: one with ARC on, the other with ARC off. This made switching between them, for comparisons, far easier than drilling down into the menu to turn ARC on and off.

There are also housekeeping controls: Display Brightness, Mute Level, Maximum Volume, and volume level at power-on.

Because I evaluated the STR full range, without a subwoofer, and only with a digital input, my setup was far simpler than the above discussion might imply. But with its ability to set up different inputs separately, use more than one setup for any input, pass along an analog input unaltered or convert it to digital for processing, and more, the STR is exceptionally flexible. I left most of the controls at their factory default settings, which meant that it took me about five minutes to get the STR up and running. Setting up ARC will take a little longer.

All listening was done with my Monitor Audio Silver 10 speakers, and without subwoofer(s). The Silver 10s were positioned about 6' out from one of the short, bay-shaped walls of my room, spaced about 9' apart and just slightly more than that from the main listening seat, and toed in so that their axes crossed just in front of the listener.

Setup: ARC
Anthem Room Correction comes with a calibrated USB measurement microphone, a mike stand, and various cables. There are two versions of the program, one for use with a PC and not compatible with a Mac OS (though Bootcamp on the Mac is claimed to work), the other for use on a mobile device (iOS only). I used only the computer version, with the mike and STR both connected directly to the computer's USB inputs.

After you've downloaded the ARC software from Anthem's website and opened it, you enter the serial number of the calibrated mike. While downloading and installing ARC is relatively straightforward, I had some minor difficulties arising from my relative unfamiliarity with the finer points of Windows. (Apart from some audio and video test programs, I do most of my computer chores—writing, e-mailing, web wandering—on a Mac.) Windows users will doubtless have no such issues, but tech help was readily available by phone from Anthem.

ARC can be set up for a maximum upper EQ frequency of 20kHz or lower; above 5kHz, the mike becomes more directional and therefore less accurate. A bass EQ limit can also be set, to avoid pushing the speakers beyond their natural low-end limits. For the same reason, the slope of that bottom-end rolloff, up to fourth-order, can also be set, and room gain adjusted. The latter can be set to adjust the response below about 200Hz; a flat in-room response in the bass typically sounds too lean. I changed it only slightly from the default.

The actual setup of ARC is well covered in the manual, so I'll just summarize here. Measurements are taken for up to 10 mike positions at and around the main listening seat, with a recommended minimum of five. The computer screen then displays the result prior to EQ correction, along with the post-EQ target curve. After the computer runs the calculation, the final, compensated curve is also shown on the computer screen. If you judge it to be satisfactory, you can then upload the correction curve to the STR. Different results (eg, with and without a subwoofer) can be loaded into each of the STR's four available Profiles.

One major advantage claimed for doing the calculations in the computer instead of, as with Audyssey, inside the preamp or pre-pro itself, is that the computer's greater processing power can do more complex calculations far more quickly. The filters derived from these calculations operate at 32/192, whereas the best that Audyssey does in current Audyssey-equipped consumer products is, to my knowledge, 24/48. Whether or not this is enough (at a sampling rate of 48kHk in most consumer applications, an Audyssey-processed source will roll off rapidly above 24kHz) is a question I won't try to answer here, as it relates to many things, not the least of which is the current audiophile interest high-resolution audio.

When Anthem regional rep Joey Perfito visited to help set up the STR, he performed an EQ all the way up to the maximum of 5kHz. But after he'd left, I did all of my early listening without EQ, to evaluate the STR's performance as a simple integrated amp. As mentioned earlier, all of my listening, pre- and post-EQ, was done with digital source material, using a direct, digital coaxial connection from my Marantz UD7007 universal Blu-ray player and, briefly, via a USB link from my computer. I didn't test the analog inputs—I had on hand no relatively new, reliable, pure analog sources with which I'm intimately familiar, and using my Blu-ray player's analog output would involve, at minimum, one extra unnecessary D/A conversion at the player's output, and add its effects, if any, to the test.

Listening: Without ARC
One of my favorite things about audio shows is discovering recordings that I might want to own for enjoyment, testing, or both. And despite the carcass that was the high-end audio portion of the 2018 Consumer Electronics Show, I did hear at least one such recording, in the Harman-Levinson-Revel room: Marcus Miller's M² (CD, 3 Deuces/Telarc CD-83534). It's not the style of music I'd normally choose (jazz fusion, featuring Miller's work on bass guitar and other instruments) but I ordered it when I got home. My enjoyment of it through the STR and my system was enormously helped by its superbly clean recording quality, with a smooth, silky, unexaggerated top end and solid imaging.

M2 doesn't feature a ton of depth, but is solidly up front and highly dynamic. The Anthem had no problem keeping up with it. I did hear a little excessive warmth and body in the bass guitar and kick drum, particularly when I cranked the volume to the levels the music demands. But experience tells me that this was a room effect, possibly aided by the Monitor Audio speakers, although, as usual, they were positioned well forward of the wall behind them. But it wasn't pervasive; on some tracks the kick drum was tighter and positioned farther back, suggesting that at least some of the warmth I heard might be in the mix as it varied from cut to cut. Overall, however, the Anthem STR never gave me reason to complain.

Nils Lofgren's Acoustic Live (CD, Vision Music VMCD1005) is something of an audiophile chestnut, particularly "Keith Don't Go," a track whose 6.5 minutes have thrilled or tortured audiophile showgoers for years. This track, now 20 years old, has somewhat faded as a demo piece, but it's still brilliantly recorded—and so dynamic that, in places, the very top-end information sounds as if it was subtly overloading the mixing desk. Nevertheless, audiophiles accustomed to six-figure amps and speakers might find it hard to credit the explosive sound I heard to a system in which the combined price of speakers and amps was $7000. The result was punchy and likely true to the source, with excellent detail and an open midrange. At one point I laid aside my notepad and just listened—which is, after all, what it's all about.

On Leo Kottke's My Father's Face (CD, Private Music 2050-2-P), the Anthem portrayed well his gravelly, textured voice, providing solid bass depth, and top-end detail supported by believable warmth. And the King's Singers' collection of Gilbert & Sullivan songs, Here's a Howdy Do! (CD, RCA Victor 61885-2), had rewarding spatial depth as one or another of the singers was given prominence in the arrangements. The sound was also a bit warm, but this wasn't particularly obvious, as this recording offers little in the way of extended bass.

That was definitely not the case with Eeg Fonnesbæk (CD, Stunt STUCD 15082), one of my 2018 picks for "Records to Die For." This stunning studio recording, featuring the voice of Danish jazz singer Sinne Eeg and the double bass (and occasional electric bass) of Thomas Fonnesbæk, sounded almost as good here as it did through a pair of Revel Ultima2 Salon2 speakers driven by a rack of Mark Levinson electronics at CES 2018. The room was different, of course, and I was depending on unreliable audio memory—I'm not about to argue that this amp-speaker combo could equal the Levinson-Revel setup. But my Monitor Audio speakers driven by the Anthem STR gave more than a taste of it, responding beautifully to Eeg's flexible, vibrant singing and Fonnesbæk's supple bass playing. While the sound of the latter had the warmth and richness I'd noted in the other recordings mentioned, its low notes were well defined, none jumping out in an unnatural way. Equally impressive were the natural mechanical details audible when a recording mike is positioned close to an instrument, including subtle sounds of fingered strings, and the occasional buzz as they snap back after a vigorous pluck.

Listening: With ARC
Despite the STR's superb sound sans EQ, I was anxious to give ARC a shot at compensating for my room, particularly by setting the maximum EQ frequency at a level that interfered as little as possible with my speakers' midrange and treble characteristics. I chose a ceiling of 500Hz; with ARC leaving untouched everything above that frequency, the speakers should still sound reasonably close to the speakers I use every day because I like them, minus most of the bass boom, tubbiness, and bloat that any room can cause. I suspect that most buyers of an STR will make a similar choice.

ARC is used in many other Anthem products, but the version included in the STR and Anthem's new STR preamp is the most advanced, with some 50% more correction capability than even the best of them. Considering that the other Anthem models with ARC are all A/V receivers and surround processors, which have to handle more than two channels and in most cases cost less than half the STR's price, that's no surprise.

I set up ARC using Anthem's recommendations, placing the mike at eight or nine different positions (I forgot to write down exactly how many—mea maxima culpa!), one of them at the point occupied by my head when I sit at the primary listening position, and the others within 2' of it. The computer did its calculations quickly, after which I uploaded the correction file to the STR. [See "Measurements," fig.3.—Ed.]

The differences I heard ranged from subtle to striking, depending on the recording played, and were only rarely inconsequential. Recordings with strong bass content saw the greatest improvement. Drums were tighter; closely spaced drum rolls, in particular, sounded more precise, each stroke more cleanly differentiated. Recordings of pipe organs, such as Jean Guillou's performance of his own transcription of Mussorgsky's Pictures at an Exhibition (CD, Dorian DOR-90117), sounded not only cleaner but more powerful. The latter was due, at least in part, to a clearing up of a room-response dip at roughly 43Hz—although, as indicated earlier, not all bass dips, some of which are "black holes" in the response, are correctable.

The sound of the double bass on Eeg Fonnesbæk was cleaned up significantly; while I'd had only minor issues with it before, now I had none. Marcus Miller's M² was tighter and crisper, particularly the bass guitar and kick drum. And while the King's Singers' G&S album was only marginally affected, the greater precision in the upper bass made the rapid patter songs easier to follow.

The application of ARC didn't alter the Anthem's exceptional sound in other respects. But some listeners accustomed to the quirks of their listening rooms might not like the result at first, particularly the reduction in extraneous "warmth." I can only recommend that they listen to their EQ'd systems for two or three weeks. The benefits of ARC in comparison over the system's uncorrected sound should then be obvious.

Conclusions
Most well-designed integrated amplifiers on today's market go about their jobs as such products always have, without altering a system's response in any significant way. That's fine, and one of them might be just right for your system and room.

But despite the current popularity of analog, particularly vinyl, there are things that can be done with digital processing, particularly when performed at high enough bit and sampling rates to satisfy the never-CDers, that we've never been able to accomplish in the analog domain. In that regard, the Anthem STR is a watershed product worth serious consideration. Highly recommended.