conductors and dielectrics), which would have sacrificed some of the AVR300's stunning transparency, articulation, speed, clean purity, spatial imaging, etc.
      Incidentally, the AVR300, like most receivers and integrated amplifiers, does not have external heat fins for dissipating heat from its built-in power amplifier. It relies on convection air currents, entering the bottom vents and exiting the top vents, to provide the needed cooling (so naturally it is crucial that you place the AVR300 on a hard smooth surface, and do not block the bottom entry vents). For continuous high power operation, the AVR300 also has a pair of small fans built into the bottom, which are thermally activated only when needed. During our testing, we never heard these hidden fans come on, which means either that they are not even needed for ordinary listening, or that they are so quiet that we never heard them.

Surround Enhancement for Two Channel Material

      The AVR300 boasts a rich and useful complement of surround processing and enhancement modes, and you can conveniently select among the available appropriate choices (for each different type of program source) by simply repeatedly pushing the Mode button on the remote (or the front panel).
      Especially noteworthy is the AVR300's inclusion of the brand new Dolby PLIIX processing mode, which can be applied to both analog and Dolby Digital source material. This mode improves upon Dolby PLII EX by deriving two distinct stereo (and full range) signals for the two back surround loudspeakers, rather than the single mono signal that was fed to both loudspeakers by previous EX and ES decoding matrices (from Dolby, THX, and DTS). Prior to Dolby PLIIX, this stereo back surround feature was only available from Lexicon via their proprietary Logic 7 decoding. As we have discussed in other reviews, employing a back surround signal and loudspeaker is crucial to achieving a truly believable sense of being transported out of your small room, and being surrounded by and immersed in the large alternative acoustic venue of the recording. Without a good back surround, we get the acoustic sense of merely peeking in the doorway from outside the large venue, and not being truly transported, to being surrounded by and immersed in that alternative space. Making the back surround signal stereo (and full range) instead of merely mono is, as we'll see below, an important further step in achieving the magic that a great surround system can provide, and the AVR300 is one of the first (if not the first) surround processors and receivers to include the Dolby PLIIX processing that delivers this.
      The AVR300 also provides a choice among the other Dolby modes (PL, PLII, PLII EX, and their Dolby Digital equivalents), and DTS modes (including 5.1, ES 6.1, and the Neo 6 surround enhancement modes). One feature the AVR300 does omit is THX processing. We particularly enjoyed the spatial imaging of the THX EX mode and some other THX options when testing Arcam's senior AV8 processor, but frankly we don't miss them now in the AVR300, because the AVR300 is so superb at portraying and re-creating spatial imaging, especially in modes such as the new Dolby PLIIX and Neo 6, as discussed below. Incorporating THX into the AVR300 would have forced the AVR300 to be more expensive (due in part to THX licensing and certification fees), or alternatively, if the price was to be held constant, would have forced Arcam to compromise the AVR300's amazing sonic quality by deleting some sonically important circuit aspects. So we think that Arcam made the right choice here.
      Now let's tackle the important bottom line question: just how good does the AVR300 sound in its various signal processing modes?
      Let's start simply, with the playing of stereo music recordings. Here your best sounding choices for surround enhancement are Neo 6 Music and Dolby PLIIX Music. As noted, the sound through the processing modes is better if you can bring the signals into the AVR300 via the digital input (if you don't want to use surround enhancement, then also bring the signal into the AVR300 in analog format, and use the Direct mode that's available for analog sources).
      Neo 6 has a big sonic advantage for well miked stereo material, in that it preserves the two front main channels essentially intact, thereby preserving very well the sonic fidelity and spatial imaging of the stage up front that was encoded into the recording. The AVR300 is then superb, in this Neo 6 Music mode, at extracting ambience from the recording and feeding it to all other loudspeakers, thereby synthesizing or re-creating a richly believable sense of being in the large hall, with the musical performers all up front. Indeed, the AVR300 with its superb transparency and spatial imaging is so extraordinary in this mode that, as mentioned above, 1955 two channel recordings can sound more convincing, at putting you in the hall with the music, than many of today's true surround multichannel recordings do.
      On the other hand, Dolby PLIIX has a sonic advantage for stereo material that has been too closely miked. Dolby processing, including Dolby PLIX, does change the signal fed to the two front main loudspeakers (in contrast to Neo 6), putting this signal through a matrix which alters the sound from the two front main loudspeakers, and bleeds off some of this main front signal to feed to the surround loudspeakers. There are a number of sonic consequences to this different surround enhancement approach. The music that was merely up front on stage is now spread out laterally, so that the stage becomes much wider, wrapping around the sides of your room. This presents a much larger spatial image of the stage than Neo 6 does, and much richer hall ambience all around you. You might enjoy this wide, rich enhancement effect on all recordings. We prefer the accurate stage image of Neo 6, for playing recordings wherein the stage space has been well recorded. But many recordings are too closely miked, and thereby portray a stage that sounds small, confined, narrow, and shallow. For these recordings Dolby PLIIX is very effective at enlarging the portrayed stage space to realistic proportions, and at richly enhancing the too dry hall ambience contained in the recording.
      Note that localization specificity, of various instruments and voices, as well as of hall ambience itself, is vaguer under Dolby PLIIX than under Neo 6, since Dolby processing ambitiously works to stretch and spread out spatial images, but does not have enough localization information from most recordings to do this with any degree of precision. Also, since Dolby puts the two front main signals through a subtracting matrix and bleeds off some musical information from these two main front channels (in order to spread that information to the surround channels), the music itself on stage does not sound as accurate via Dolby enhancement as it does via Neo 6 enhancement. Specifically, the music on stage becomes softer, and phasey in quality, losing the coherence and accurate transient attack that you get via Neo 6. These changes are simply a function of the Dolby matrix strategy, and are common to all surround processors. Indeed, it is to the credit of the AVR300 in particular that it reveals so clearly all these subtle spatial and sonic differences between these two surround enhancement modes.
      As you switch between these two modes, you'll need to adjust at least the volume levels (and probably also delay times) of all surround loudspeakers, in order to optimize the surround enhancement of each mode. When you switch into the Neo 6 Music mode, you'll need to turn up the level of all surround loudspeakers more than you had for optimizing the Dolby PLIIX Music mode, or other Dolby modes (and you'll probably also want longer delay times to the surround loudspeakers). That's because the Neo 6 processing only puts the subtle ambience information into the surround loudspeakers. Dolby processing, in contrast, puts some of the main music into the surround loudspeakers, which of course makes all surround loudspeakers louder in level, and this means that you'll need to turn down the level for all surround loudspeakers to less than you had for optimizing Neo 6. The AVR300 features a handy volume level trim adjustment, quickly accessible by a dedicated button on the remote, so you can easily change the relative volume levels of the various surround loudspeakers as you need to, when you change processing modes. Incidentally, the AVR300 also features improved ergonomics for these trim controls, which are now less volatile than they were in earlier Arcam processors (they now hold their setting as you switch modes).
      The AVR300 does not have memory presets for storing various preferred settings (volume levels, delays, etc.) for various modes, since, though memory chips themselves are cheap, it is expensive to implement the software required for memory presets, which would have prohibitively increased the price of the AVR300. While memory presets are a wonderful feature, we have gotten used to life without them, since we found that even the 5 presets provided in Arcam's senior AV8 processor are not enough, in order to accommodate all the settings we wanted for various kinds of program material. So for now we just think of the AVR300 as having the hands-on charm of a manual stick shift in this regard, rather than the lazy convenience of an automatic transmission.
      We found that the Neo 6 mode in the AVR300, while doing a spectacular job of surround enhancement, made slight tonal balance changes to the signal, slightly brightening the upper frequencies and slightly leaning out the warmth and bass regions. We found that this slight tonal balance was very easy to acclimate to and enjoy, in the same way that one acclimates to and enjoys hearing a live symphony orchestra in a brighter modern concert hall rather than a darker sounding, plush, older concert hall.
      We also found that, if you want to, this slight tonal balance shift is very easy to compensate for. Simply turn the subwoofer level up a hair, and employ the AVR300's handy tonal balance trim controls. The AVR300 features a comprehensive set of bass and treble tone controls. They are adjustable firstly via the setup menu, so you can adjust the overall system to your room and taste, and you can also compensate for differing tonal balances among various loudspeakers or among various loudspeaker locations in your room. Then these tone controls are also adjustable via a handy, easily accessible tonal balance trim adjustment, which is useful for further altering your basic system tonal balance setup, in order to suit particular program material or in this case particular surround enhancement modes like Neo 6. An especially useful feature in this AVR300 tonal balance trim control is the ability to access all loudspeakers at once, so you can quickly adjust the bass or treble for your entire system for a particular piece of program material or surround enhancement mode.
      The AVR300's sonic performance is so superb that it makes the most out of these two surround enhancement modes, more than any other processor regardless of price. We previously praised Arcam for making products that open a new frontier in surround sound, mastering the rich and accurate reproduction of space itself. And we discussed in previous reviews the crucial importance of reproducing space, in order to suspend your disbelief and aurally transport you out of your small listening room and convincingly immerse you in an alternative large venue. The AVR300 continues this Arcam tradition of mastering space, and indeed takes it to new heights. The AVR300 is so superlative in transparency, and clean purity, and articulation, and coherence, that it clearly and accurately reveals very subtle sonic cues in the recording, cues about the music itself and also about the space around the music, including the entire space of the recording venue. Because the AVR300 is so superb at reproducing and revealing these subtle sonic cues about space itself from each recording, the AVR300 gives these surround enhancement processing modes more information to work with. And that in turn means that these modes, when heard through the AVR300, give you a far richer and more believable sense of surrounding space, even from mere two channel recordings.
      The AVR300, like all other processors, also includes some other obligatory two channel signal processing modes, which are less useful, and which also don't sound as good as they make their way through the DSP that does the signal enhancement processing. For example, the simple Dolby PL (Pro Logic) mode implements the old, original Dolby Pro Logic processing, and is included just for playing legacy recordings. Its sound is dull, and the Arcam manual even specifically warns you that this mode is sonically inferior. Another mode that gets processed through the DSP, the straight Stereo mode, is likewise sonically disappointing, sounding artificially midrangy, hard, clogged, and spatially flat and two dimensional. Here Arcam is at the mercy of the DSP manufacturer (Crystal), who has pre-programmed these special processing modes into the DSP, and Crystal has evidently done something surprisingly wrong processing this seemingly simple, straight mode through the DSP (even though they did a wonderful job with the great sounding Neo 6 and Dolby PLIIX enhancement processing modes, which of course involve far more complex signal manipulations within the DSP). Fortunately, you'll never want to bother using this Stereo mode through the DSP anyway, since, for playing two channel material in straight stereo, you have the far better sounding (indeed spectacular) analog input Direct mode available in the AVR300.

Surround Processing for Multichannel Material

      Next, we turn to the AVR300's processing modes for digitally input multichannel program material, including of course music videos and film soundtracks on DVD. The AVR300 features the usual array of processing modes seen in today's surround processors, including Dolby Digital 5.1, EX, DTS 5.1, and ES 6.1. Then, the AVR300 also includes a brand new processing mode called Dolby Digital Pro Logic IIX, which is an extension upon Dolby Digital 5.1 EX, but also seems to us to be much more, since it exhibits many sonic improvements over EX, which suggests to us that many of its design and operating parameters have been refined over EX. Note that these Dolby Digital processing modes operate upon a discrete 5.1 digital signal, whereas the Pro Logic IIX Music and Movie modes discussed above operate upon a two channel signal (which can be input via analog or digital routes).
      One unique technical advantage of Dolby PLIIX is that it feeds the back surround loudspeakers with distinct stereo signals, derived from the left and right side/rear surround channels, rather than with merely a single mono signal, as Dolby EX and DTS ES do. Thus, for the first time from a major processing software vendor, you can get 7 truly distinct and full range channels arrayed all around you (Lexicon had previously offered a similar feature in their proprietary Logic 7 processing). So far as we know, the Arcam AVR300 is the first surround receiver to offer this brand new Dolby PLIIX. More importantly, because the AVR300 is so superlative at sonic transparency and spatial portrayal, it can take full advantage of the new spatial imaging properties offered by Dolby PLIIX, and bring these spatial properties to you at their best.
      As you might expect from the AVR300's superlative prowess in all the other modes evaluated above, it also does a superb job here, in all the other usual (Dolby and DTS) processing modes for digitally input multichannel sources, portraying space and subtle details (of music, dialogue, and sound effects) better than any other surround processor or receiver, regardless of price. That's extremely high praise, and praise enough. But you ain't heard nothing yet. For we are reserving the bulk of our discussion here for the brand new processing mode implemented in the AVR300, Dolby Digital PLIIX.
      How good does the new processing mode, Dolby Digital PLIIX, sound, as implemented in the Arcam AVR300? And how does it compare to the other processing modes? Let's just say we are almost at a loss for words. Dolby Digital PLIIX, as performed by the Arcam AVR300, is a huge leap forward in home theater sound. Its improvement in spatial reality and believability over other processing modes, even the recent EX and ES processing modes, almost beggars description. We could write an entire review of just the sound of the Dolby Digital PLIIX mode of the AVR300, and the advances it gives you for all music videos and film soundtracks (including film soundtracks that are not encoded for PLIIX nor even for EX). Indeed, the surround sound improvement is so dramatic that, with the AVR300 being one of the first products to offer PLIIX processing (and offer probably the best sounding implementation of PLIIX for some time to come), we would urge all serious home theater connoisseurs to rush out and buy the AVR300, even if you use it only as a Dolby Digital PLIIX processor for the rest of your system. It's even hard to know where to start, in telling you all the sonic improvements wrought by the AVR300 using Dolby Digital PLIIX.
      In previous reviews, we have discussed extensively how a back surround channel, with full or nearly full spectral range, is crucial for truly transporting you out of your small listening room and immersing you in the large alternative spatial venue of the recording. With a 5.1 loudspeaker setup (no loudspeaker directly in back of you), it sounds at best as if you were merely standing at the doorway of the large alternative spatial venue, peeking in. With Dolby EX or THX EX or DTS ES processing and one or two loudspeakers directly in back of you, the large alternative spatial venue for the first time sounds as if it is all around you. And this crucial effect and benefit is realizable even with recordings that have not been specifically encoded with EX or ES information.
      Likewise, in previous reviews we discussed how EX or ES processing, feeding a back surround loudspeaker, unexpectedly provided further sonic benefits to the spatial imaging up front on stage. With straight 5.1 processing and no back surround loudspeaker, the stage image is portrayed as flat and two dimensional, and all sounds coming from the stage seem like flat cardboard cutouts. But with EX or ES processing and a back surround loudspeaker, the sounds on stage pop out, into a three dimensional, flesh and blood solidity that is far more believable and enjoyable. Again, this crucial effect and benefit is realizable even with recordings that have not been specifically encoded with EX or ES information.
      It's worth noting that these sonic benefits from EX or ES processing are realizable with either one or two back surround loudspeakers, and it makes sense that there is little difference, since plural back surround loudspeakers are still fed the same single mono signal, by EX or ES processing. In fact, in our experimental research we found that the spatial imaging benefits from EX or ES processing improved as we moved the two back surround loudspeakers closer and closer to each other, which means that the best sound of all was realized by the limiting case of this experimental movement, namely coalescing both back surround loudspeakers into one single back surround loudspeaker.
      Both the above types of sonic improvement, provided by EX or ES processing and at least one

(Continued on page 133)