AV Receiver Reviews

Overall, the THX processing is mostly all or nothing- there is no a la carte disengagement of Re-EQ for example. But everything works as advertised and although years ago I found THX a little too heavy-handed in frequency contouring, the improvements of the Ultra2 processing suite are very real and welcome.

Remote Control
"Alex, I'll take 'Remote Possibilities' for $200."

"I love this remote. I really, really love this remote."

Bzzzzp!

"Things you never hear Fred Manteghian say in a review?"

Yup, that's right. I love this Denon's remote. It is a hybrid device, perfectly sized, with hard, day-glo buttons on the bottom half and a membrane pad on the top with really cool blue graphics that change dynamically. You do have to take your attention off the TV to see what you want to select on the membrane, but the blue is very easy on the eyes and your thumb will have no problem finding the right "button." You also get nice tactile feedback when you press a button, much like a hard-button remote.

As with most receiver remotes, the Denon's will control other components. So if you pick "DVD" from the hard DVD button on the bottom half, the soft membrane shows you DVD transport buttons. Of course, I wouldn't want to depend on these for any vigorous forward, rewind, type action, but for the occasional, "could you pause it, I'm going to the kitchen," it's more than sufficient. [The remote shown in the photo is the one furnished with Denon's AVR-4306 receiver. Fred reports it is identical in layout to the 4806 remote, apart from the part number below the button array.—Ed.]

A Space Audyssey
As expected, the Denon's speaker configuration setup system is fairly extensive, allowing you to set separate crossover frequencies to the bass for your main speakers, centers, side (individually for both the "A" and "B" outputs!), and surround channels. But unlike the Casablanca preamp-processors from Theta, you can't adjust the crossover slope itself. Denon provides a small, disc-shaped microphone with an attachment for a tripod (not included) in its base, and an automated, easy to use room equalization routine. Lacking a tripod, I pulled out my trusty boom microphone stand and obtained good results.

The first step in calibrating involves testing the speakers with a short series of pulses sent to each speaker position. The program then asks you to move the microphone to the first (primary) listening position and let the receiver retake measurements from there. After that, you are instructed to move the microphone to the second listening position, where more measurements are taken, and so on and so on. Denon recommends you visit at least six listening positions. I only had four really, so I did the two coveted spots twice. Only pulses are used during the measuring process. A built-in pink noise tone generator is available elsewhere during setup (or directly from the remote) for adjusting channel levels if you're not happy with the results of the automated results.

The next step is to let the Denon "calculate." This process took five minutes for my six measurement locations. After the calculation, you can pick one of three equalization methods (four, if you count "off"). You can change EQ methods later, without having to re-measure the room, so feel free to experiment.

One of the equalization modes is called "flat," which attempts to drive each speaker to produce as flat a frequency response as it can. With my MartinLogans, speakers known to roll off in the upper frequencies, the results were most unnatural. Another available mode is called "Front," and it attempts to EQ the signal sent to your center and surrounds so they will sound like your main left and right front channel speakers. This is also intellectually and subjectively not recommended, in my view.

The final EQ mode is called "Audyssey," because it uses Audyssey's room equalization algorithm to meld frequency response curves from multiple measuring locations into a single EQ curve that provides the best compromise for all listeners in the room. Not surprisingly, this mode sounded best and most natural overall. Obviously, you can't set delay times relative to all the listening seats in the room, so that first (primary) measuring location is used for calibrating delays and listener-to-speaker distances.

I did run into a bug in the process. My center channel, which I had set manually as "small" with an 80Hz crossover prior to the EQ process, was set to "large," with a 60Hz crossover, after the EQ process. Never mind that a "large" speaker, by definition, requires no crossover. This bug was odd (and repeatable), but hardly serious. I simply reset the center to be small with an 80Hz crossover and went about my business with no perceived ill effects.

I was curious to see how well the automated channel-level calibration would compare to my tried and true method. I made note of the channel levels set by the automated process (column A in the figure below) and then pulled out my trusty Radio Shack SPL meter. First, I measured the channel levels using the receiver's built-in pink noise generator without changing the channel levels set by the EQ process (see column B). As you can see, the front channel, center channel and subwoofer measure within 1db of each other, which is within the margin of error of the SPL meter, and an excellent result overall. The surround channels, however, were considerably down in level, something I will blame on the introduction of my big head when taking the manual measurements.

Next, I manually calibrated the system, again using the Denon's pink noise. Because the Radio Shack's accuracy is best when hitting around the zero at the center of it's needle path and quite hard to read at either extreme, I decided to play with the Denon's channel level settings until I could reach 78 db on the meter in all speakers (column C). Once I had those figures, I backed down the front left channel's setting by 2db to bring it in line with what the automated EQ process had for that channel, and then backed all the channels down an equal 2db. The results in column D are, as you can see, pretty close, but there's no doubt that the Audyssey system does a fine job with very little fuss.

An Eye for Detail
The Denon manual and website, somewhat uncharacteristically, avoid any name-dropping when it comes to the video processing being used in the AVR-4806CI. But a phone call clarified that it is in fact Faroudja that's responsible for what I can only say is the best video processing I've seen yet in an AV receiver. The Denon will not only pass any 480p, 720p, 1080i, or 1080p source, it will also upconvert any video source to these resolutions as well.

I may not have a high-definition video player yet, but with my recently acquired DirecTV HR20 DVR I have access to lots of true HD programming. While I can't say that DirecTV's signal is as good as a high def player's, the over-the-air feeds of Lost are about as good as high-definition gets. And the Denon is truly transparent. While I've always been a proponent of "going direct" from your video source to your video display, the Denon adds more than just the convenience of switching, it offers a fantastic picture quality as well.