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The Soul of Your System

Last month we discussed the importance of spending the lion’s share of your resources (meaning both time and money) on your speakers. That’s because they make the biggest difference in the sound of your system. You may choose a pair of speakers for a traditional, two-channel stereo system or you may purchase seven or more speakers for a full-blown A/V surround-sound system. Whatever your setup, you must choose your speakers based upon personal preference because speakers are the most subjective component in terms of sound.

After you have chosen the speakers that sound the best to you, you must now choose the best component to power them. This is the power-amp/pre-amp combination or having these components all in one chassis, the receiver.

Some audiophile purists maintain that separating the power amp, signal processing and AM/FM tuner stages into three discrete chassis yields the cleanest, most interference-free signal. But the vast majority of customers choose to incorporate power-amp, pre-amp and receiver into one. And with the incredible new surround-sound technology as well as a host of other amazing features, the new breed of A/V receivers delivers as good a sound as I’ve ever heard-and some of the flagship models are approaching audiophile prices, too.

The Ever-Evolving Surround-Sound Technology

Surround sound became famous thanks to Star Wars. George Lucas pioneered the art of choreographing the sound with the picture to deliver the most awesome action scenes. We all remember the Federation starships careening over our heads: not only did they shoot past us visually, but their screeching sound followed the picture precisely. Dolby Labs produced this effect, the same company that brought us noise reduction technology for tape recorders.

After the runaway success of surround-sound in the theaters, Dolby helped to bring surround-sound home and produced its first consumer-chip set, called Dolby Surround Sound. Dolby Surround Sound is an encode/decode system that requires “directions” for the sound to be encoded onto a video tape or laser disc during the video-editing process. The chip built into the receiver would then decode the sound upon playback, sending it to one of four different speakers throughout the room.

The first Dolby Surround Sound system, released in the 1980s, consisted of four speakers-two front main speakers, and two rear effect speakers. But in essence, Dolby Surround Sound was only a three-channel system. The rear-channel speakers each delivered the same monaural signal, so the effects could only move front to back with the picture, but not side to side. That was not the only deficiency with the original Dolby. The other issue was the movie’s dialog. In the theater, a discrete dialog channel was placed behind the screen so it seemed as though dialog was coming from the actors’ mouths. The original Dolby created a so-called phantom channel, which synthesized a center channel out of the left and right speakers. Unfortunately, this system sounded muffled, and tended to obscure the dialog, especially when it competed with other simultaneous sounds.

By the early 1990s, Dolby upgraded its three-channel surround-sound to a four-channel system called Dolby Pro Logic. Pro Logic utilized a center-channel speaker that sat atop your TV set and was much more effective for recreating realistic dialog. It also allowed the main speakers to work more efficiently by removing all dialog responsibilities and allowing them to focus on sound and music. Even though Pro Logic used five speakers, it is only a four-channel system since the rear-channel speakers are still mono.

Pro Logic’s problem was its wide performance variation, depending upon the brands and models of components that varied by manufacturer. These variations in movie theater sound systems’ quality, as well as those of home ones, caused George Lucas and his ace sound engineer, Thomlinson Holman, to create THX. THX is not a surround-sound format, but rather a strict set of standards set for Dolby Pro Logic. In order to become THX certified, receivers and processors have to deliver incredibly accurate sound measured by the signal-to-noise and distortion ratios, but also by a receiver’s ability to “steer” the sound from speaker to speaker accurately. The speakers also must conform to the same tough standards. Overall, THX surround-sound was the best available-and also the most expensive, costing up to 10 times the price of a normal Pro Logic system.

By the mid-1990s, Dolby advanced the cause again by delivering Dolby Digital. This system takes advantage of the cleanliness and accuracy of digital technology, ensuring a greater consistency between models than did the analog Pro Logic. Unlike the four-channel Pro Logic system, Dolby Digital is a full-blown, five-channel system delivering stereo, rear-effects speakers, allowing the effects to move from side to side instead of just from front to rear. Dolby Digital also boasts a dedicated low-frequency output specifically for a subwoofer. A subwoofer is a large speaker that delivers low bass sounds and adds another dimension of excitement to movies and music. This channel is of limited range and is thus referred to as the “.1” channel, making Dolby Digital a 5.1-channel surround-sound system.

The nice thing about Dolby Digital is the fact that it is a universal standard among all of the new digital delivery media including DVD, DIRECTV, DISH Network satellite systems and HDTV. Since nothing in the world of consumer electronics is easy, there are some wrinkles in the surround-sound fold. The first one is DTS, a competitor to Dolby Digital, backed in part by Steven Spielberg. This technology is designed for music and movies and boasts a better audiophile-type sound than Dolby Digital, which DTS claims doesn’t sound as good with music as DTS does. Although DTS has gotten decent support from the hardware companies, the music and movie studios haven’t really gotten behind the technology and there are not many titles available in DTS.

Another wrinkle is the recent addition of a 6.1-channel system from both Dolby and from DTS. The additional channel for both systems is a center channel in the rear. This adds another dimension of effects and, in essence, allows the viewer to localize a movie’s effects to the rear for enhanced performance. For this latest surround-sound enhancement, Dolby Labs has teamed up with THX to produce Dolby Digital EX. DTS also has a competing 6.1-channel technology called DTS ES. The future of 6.1 is still unclear, so stay tuned for details.

Other Benefits of New A/V Receivers

Besides surround-sound, an A/V receiver has a few other tasks to perform. First and foremost, the receiver has to drive your speakers. This means that they have to contain large enough amplifiers to deliver enough power to make your speakers sound their best. Most speakers nowadays are efficient enough so that they do not require gobs of power for decent sound. But there are some exceptions, including more exotic speaker designs such as electrostatic and planar. These more power-hungry designs would probably work best with a dedicated power amplifier, so make sure that you work closely with your A/V salesperson to choose the correct amplification.

Remember that surround-sound receivers have to power at least five speakers, so make sure that it has enough juice to do so well. This means that the surround-sound channels should have the same power output as the main channels-or at least 75% as much. Your receiver should also have a dedicated low-level subwoofer output, to take full advantage of the .1 subwoofer channel in Dolby Digital.

Besides power, a good A/V receiver should have the switching capability to act as the apex for your entire A/V system. This means that it should have the inputs and outputs necessary to hook up all of your existing (and future) components. Some accommodate all sorts of formats, such as S-video, component video, optical and coaxial digital, IEEE-1394 and others. Another helpful feature along these lines is an on-screen display that tells you what component is currently in operation.

Finally, many receivers allow for multiroom and multizone capability. This means that you can listen to one component in one room, and another component in another room. In order to pull this off, a receiver has to have inputs for remote infrared sensors (or RF capability), as well as multiple amplifiers built in. You can snake wires in the walls and hook up remote speakers and sensors so you can hear a CD in the study, while your kids watch a movie in surround-sound in the den.

Harmon/Kardon AVR-7000 Surround-Sound Receiver

This top-of-the-line product from H/K incorporates some very interesting future-proof features. The first one that is immediately visible is a front-panel A/V input/output. This jack set can be configured to be either an input or an output-perfect for a simple camcorder hook-up, but also good for dubbing onto a MiniDisc or It also has the ability to add supplemental amplification to all five channels, as well as an outboard decoder/SACD/DVD Audio player.

The AVR-7000 includes 5.1-channel Dolby Digital and DTS decoding. Even though it does not feature the EX or ES feature of those brands, respectively, it does include something called Logic 7. Logic 7 is a spin-off of a technology from another Harmon company, Lexicon. It uses digital signal processing to enhance the existing surround-sound modes with two additional digital ambiance effects, Cinema and Music. These two modes add an exciting three-dimensionality to the existing standard surround-sound modes.

The AVR-7000 also hosts multiroom/multisource A/V outputs and functions, as well as power amplification that delivers more than 100 watts into each of five channels. The H/K AVR-7000 sells for around $1800.

The Denon AVR-5800 Surround-Sound Receiver

This brand-new flagship receiver from Denon boasts just about every feature we’ve seen in a surround-sound receiver to date. It sports pretty much every type of surround-sound available, including both Dolby and DTS. It includes Dolby’s THX-EX 6.1 system, complete with seven discrete built-in amplifiers. But it also includes two types of 7-channel DTS systems: DTS-ES 6.1 Matrix and 6.1 Discrete. The Matrix version synthesizes a seventh, rear channel, whereas the Discrete version delivers its own dedicated information to the rear center speaker. DTS Matrix is a system that exists in theaters currently, whereas the AVR-5800 will be the first time consumers can hear the new DTS 6.1 Discrete system.

Another noteworthy aspect of the AVR-5800 is its three-source/three-zone technology. This allows you to listen to three different sources (e.g., a CD player, the radio, a DVD player in surround sound) at the same time in three different locations. You can be listening to sports radio in the kitchen while your spouse is listening to a CD in the bathroom, while your kids are watching a movie in surround-sound in the living room-all with a single receiver. What’s even cooler is that its remote control-the AKTIS-RF remote-will run the system via a radio frequency, so you don’t have to run remote control wires or be within line of sight to manipulate the system. But in order to utilize its RF capability, you must purchase an additional RF base module for $179.

The AVR-5800 is also quite future-proof. It allows DSP software upgrades via its RS-232 port. It also can be upgraded to offer IEEE-1394 Firewire connections, and it offers two sets of 7.1-channel inputs for future uses such as SACD and DVD Audio. What price would you expect to pay for this ultimate receiver? It lists for $3,800.

The Kenwood VR-4700 Surround-Sound Receiver

If the price of the Denon is a bit rich for your blood, you can still have a top-of-the-line A/V receiver for less than half of the price. Kenwood-another trusted name in consumer electronics-recently has delivered a new model that is filled with great features, delivers killer sound and looks pretty cool too.

The VR-4700 is sleek and silver-and a far cry from the usual black battleships one usually thinks of for audio components. It also has a very cool touch-screen remote control that controls the receiver via RF instead of IR. This allows you to operate the functions of the receiver from another room, through walls and ceilings. The remote is a two-way vehicle, so you can see the operating status (e.g., volume level, input, etc.) from anywhere in the house (or yard). The one caveat, however, is that you cannot operate non-Kenwood devices via RF, only through traditional line-of-sight IR.

Unlike the Denon, the AVR-4700 does not process 7-channel systems. Instead, it is limited to the current fare: Dolby Digital, DTS and Dolby Pro Logic. It does feature two component video inputs and one CV output, and it will upgrade composite (standard RCA) video, as well as S-video, to a component video output. This allows you to maximize the superior component video input of your digital TV, even with standard, noncomponent sources.

The AVR-4700 has a powerful five-channel amp that delivers almost 100 watts per channel, and it sells for a reasonable price, around $1,500.

Originally Published