Denon AVR-5805 AV Surround Receiver:
Page 3 It worked, and sounded superb in the bargain. As always, the make-or-break factor was the quality of the program material, but put on a great DVD-Audio disc like Organ Spectacular (Ton Koopman, Teldec) and the Denon will create an outstanding blend of depth, spaciousness, and natural tonal balance without a trace of edginess or grit. Paul Simon's You're the One (Warner Brothers DVD-Audio) was reproduced as a silky-sounding recording with a sweet top end, a deep, wide soundstage, and strong (if rather warm) bass.

On the SACD side, The Chopin Ballades & Scherzos (Arthur Rubinstein, RCA), sounded like it might have been recorded yesterday, with its big, opulent, dynamic sound. Its 1959 origins are audible only as a little roughness on the loud bits and a trace of tape hiss. And Eric Bibb & Needed Time's Good Stuff (Opus 3, 4.0-channel) had a smoother, more open sound and greater subtlety of timbre on the Denon than you're likely to find in any dozen CDs.

While not all recordings sounded this good (and CDs, on average, were a notch down from these high resolution DVD-Audio and SACD recordings) the point is that the Denon AVR-5805 is capable of outstanding music playback in keeping with its high-end price.

(At this stage in the life of SACD and DVD-Audio releases, both formats appear to be sucking wind in the marketplace. When—if?—we get a single successful high definition video disc format, I believe we can expect a high resolution music mode to emerge for that platform, rendering today's SACD and DVD-Audio formats irrelevant.)

I wasn't particularly crazy about the modes Denon offers to turn two-channel material into 5.1-channel (or higher) surround. They're typical of the sort of gimmicky modes we've always had in receivers from major manufacturers. Among the usual "Stadium," "Church," etc. (why do those simulated churches and stadiums always sound empty?), only "Jazz Club" was reasonably listenable, and even then only if you don't mind a small dose of slightly artificial-sounding reverb.

And I didn't much care for the Denon's other, less intrusive, two-channel conversion modes like Pro Logic II Music and Matrix. Denon's 5-channel stereo mode generates a center channel by combining the in-phase, common components of the left and right, and duplicates the front left and right channel signals in the left and right surrounds. This might be useful for a party, as it's certain to fill the room with a huge, amorphous blob of sound. But it's certainly not a mode that an audiophile would choose for serious music listening. Denon claims that this is their most popular listening mode for 2-channel playback, and if true I find that fact either more than slightly depressing or confirmation that Denon owners throw a lot of parties.

The Denon will receive both two-channel and multichannel digital sources through the normal digital inputs, the HDMI inputs, the IEEE 1394 connection (from a suitably equipped player), and the Denon Link (which as noted earlier I did not test). In theory these should all sound the same, but they did not. I preferred a standard coaxial digital input for CDs and movie soundtracks, followed closely by IEEE 1394. HDMI audio came up last, with slightly leaner bass and a rougher, brighter treble.

You can listen to the sound of an HDMI source from one of the standard digital inputs instead of from the HDMI connector, but you will first have to configure the Audio Setup menu accordingly. Otherwise the receiver defaults to decoding the audio coming in over the HDMI cable.

The Sound of Movies
In full cry with some of the best soundtracks available, the Denon did not disappoint. It was as full-blooded and dynamic as any receiver or pre-pro combination I've heard. And while it never ran out of steam on the big stuff, it handled small and delicate details every bit as well.

I've been watching a lot of TV on DVD lately, and the quality of the best 5.1-channel TV soundtracks can approach that of some of the best films. Battlestar Galactica is a current favorite. The 10-episode Season 2.0 set just came out, and it's a knockout in every respect—dramatically, visually, and sonically. The soundtrack here is only occasionally spectacular in an explosive way, but the clarity and spatial qualities of the music and atmospheric effects were often stunning. The Denon gets it all, including the pounding drums to the ethereal vocals in the music score that elevate the already compelling drama (the best dramatic hour on television today) to an even higher level.

All of my favorite reference movie soundtracks were fully realized as well. Master and Commander, The Far Side of the World is one of the most complex sound mixes you'll find. From the shattering sounds of battle, the explosive power of the stormy seas around Cape Horn, to the startling impact of the ship's cannons and the superbly recorded music score, the Denon nails it.

Steven Spielberg's The War of the Worlds, whatever you might think of it as a movie (I liked it, didn't love it), has one of the most challenging bass tracks around (though one or two scenes from the new Flight of the Phoenix remake surpass it). The Denon handles all of it with ease, not to mention a few other horrific audio effects, like the wail of the alien tripods.

Of course, when it comes to bass in my review system, we're talking of a line-level output to the subwoofer. I used the Denon as many of you might—with all of the main channels set to Small (crossed over at 80Hz in my case) and one subwoofer handling the extreme bottom end.

But how a receiver handles bass redirection and how it performs the crossover play an important role in how the bass will sound. Also important, of course, is how the bass will interact with your room. And that brings us to. . .

2006: A Space Audyssey
I noted earlier that the AVR-5805 includes a new equalization system from Audyssey Laboratories, called MultEQ. Briefly put, MultEQ is a sophisticated DSP process for high resolution room/system equalization—with a correction curve that is claimed to improve the response at all listening seats, not just the primary one (as is the case with typical equalization techniques). Its algorithms do not operate as a conventional equalizer (graphic, parametric, etc.). Rather, they employ a far more precise sampling technique using FIR filters with up to 512 taps positioned across the entire audible frequency range. Many of those taps are concentrated in the bass range, where they are said to provide good resolution down 20Hz.

The 512-tap MultEQ XT system used in the AVR-5805 is now available in several other, less expensive models in Denon's receiver lineup, and is the most precise realization of the system. As few as 32 taps are used in less sophisticated versions of MultEQ.

To configure MultEQ you must use the automatic system setup mode together with a (provided) microphone. The on-screen menus guide you through the steps. You can run the calibrations at up to eight listening points, after which the system combines them in a way that, in theory, provides good results throughout the listening area. (Some seats will always be slightly better than others, but the point of the exercise is to make the differences less pronounced than they would be in an unequalized system.)

The auto setup not only equalizes the system, but also automatically determines whether to classify the speakers as large or small, chooses the crossover points, and sets the individual channel time delays and levels.

MultEQ Problems—and Results
When our review sample of the AVR-5805 arrived several months ago its software was flawed in a way that did not allow it to properly function below about 65Hz—the very area where you need it most! Fortunately, other business delayed the start of our review until I could obtain corrected software.

The 5805 is not a truly modular design, so updates are usually limited to changes that can be made with new software. The receiver has both both Ethernet and RS-232 connectors for that purpose, but I was unable to get my PC laptop (with its USB output and an adapter cable) to download the new Audyssey software to correct the MultEQ problem.