encoded in true surround sound, so that you could be aurally transported to the original event in the original venue. That's what this new Arcam-based system can give you.
These Arcam units are worth their weight in gold, just for the added dimension (literally) that they can bring to all your two channel sources and treasured recordings from the past. Suddenly, from two channel sources, you can clearly hear things that were never there before. You can clearly hear the hall space of the original recording venue, and can often put enough of that alternative space around you so you are convincingly aurally transported to that alternative space (just as you would be by a good surround recording). The various instruments and voices acquire a solid, three dimensional palpability, instead of the phantom, ephemeral, flat quality they have in mere stereo playback. These various instruments, voices, etc. pop out of the flat constraints of stereo's two dimensional curtain, and are richly arrayed at various three dimensional locations in the portrayed large hall space. And, with these various sound sources being so believably solid and so richly arrayed, it becomes much easier to hear subtle inner details of the recording, and to hear into complex orchestration.
Contributing Sonic Factors
What sonic factors allow these Arcam units to conquer the final frontier of space so effectively? To be sure, they feature a rich array of processing controls (including delay and level trims), which can be (and must be) fine tuned - in order to portray a truly convincing alternative surround space, and to get each of the instruments, voices, etc. to have just the right three dimensional solidity in itself and to pop out into a rich array of three dimensional space (instead of being confined to a flat two dimensional line between loudspeakers). But most other surround processors also feature such controls, and yet they cannot conquer space as these Arcam units can.
The key to the Arcam units' mastery of space seems to lie in their superb handling of audio's classic sonic virtues: transparency, resolution, and clean purity. These classic sonic virtues have long been the goal for high fidelity through the monaural and then stereo eras, and nowadays these classic sonic virtues have been very well mastered by the best high end two channel stereo components. But most of today's multichannel equipment has not yet mastered these classic sonic virtues, and indeed has taken a step backward, with degradations in transparency, resolution, and clean purity compared to the two channel state of the art. In part this degradation is due to the added complexity of circuitry needed to handle many signal formats and to do many kinds of signal processing. In part this degradation is due to the inevitable reliance upon IC chips to handle most of this complex signal processing. And in part this degradation is due to construction economies imposed for the sake of cost (and chassis real estate) when executing such complex signal handling for so many channels.
But these Arcam units have taken a giant step forward, for multichannel signal processing equipment, in mastering the classic, basic sonic aspects like transparency, resolution, and clean purity. These Arcam units set a new standard, a new higher plateau, for multichannel audio equipment with complex signal processing. These Arcam units are so good that they are the first multichannel signal processors that merited our whole battery of purist sonic tests that we would normally reserve for the best state of the art stereo components - sonic tests that other multichannel processors fail miserably, but which these Arcam units passed with excellent flying colors.
Our battery of sonic tests (discussed below) easily verified independently that these Arcam units sonically excel in parameters such as transparency, resolution, and clean purity. For example, on our best stereo recordings of music and voice, the Arcam DV27A DVD player was able to resolve and transparently reveal musical subtleties on a level competitive with the best dedicated CD players. This is an amazing feat for a complex DVD player, and it puts this Arcam unit far ahead of most other DVD players, which are sonically compromised by all the additional complex circuitry, clock timings, noise, and processing that must be included in a DVD player, contrasted with a CD player.
We had immediately noticed how these Arcam units were mastering space itself, after we had carefully fine tuned the whole system to optimize the surround soundfield. In the beginning, when we first heard this, we knew that these Arcam units were opening a whole new higher plateau in the mastery of space, the final frontier. But we weren't quite sure why these Arcam units were so much better at revealing space than competing surround sound units. Then, later, it suddenly made obvious sense, after we had independently verified how superb these Arcam units were in handling the classic basic sonic aspects like transparency, resolution, and clean purity.
You see, the indirect sonic cues embedded in a recording, the cues that define the sonic space of the recording venue, are among the most subtle and delicate pieces of information contained in a recording. What, after all, could be more delicate, more elusive, more ephemeral, than the sound of space itself? If audio equipment is superb at transparently revealing nuances of the direct music and voice sounds captured on a recording, then, and only then, does it stand a chance of also revealing the elusive, ephemeral, delicate indirect sonic cues that define space itself, the air itself. These Arcam units were successfully revealing these subtle indirect sonic cues of space itself, to a far greater degree and with far greater accuracy than other surround sound equipment. And thus these Arcam units enabled us to hear these subtle spatial cues for the first time, and thereby utilize these cues to then fine tune all system parameters, so that our whole system could recreate surround space itself to a convincing, believable, indeed undeniable level that far exceeded what we had ever experienced from any other surround sound system before.
Only the Arcam units gave us the spatial sonic clues we needed, to then fine tune the system until we could finally achieve that magically believable, indeed undeniable, surround portrayal of space itself. Other competing units we tried didn't even let us get started on this fine tuning process, because they simply didn't reveal enough true spatial information from the recording.
Incidentally, even with the Arcam units this process of fine tuning a system for true surround space is still a laborious, time intensive task, requiring an expert ear and experienced brain to accomplish. It chiefly involves fine tuning the various loudspeaker levels, delays, and exact positions in the listening room (as well as the listening seat location). The person doing this fine tuning has to know what subtle sonic clues to listen for, how to interpret them, which system parameters to adjust and in what direction and by how much - and then how to interpret the new, different sonic portrayal of surround space after each adjustment (in what ways is it now better, in what ways is it now worse, what do these better and worse aspects indicate, and what adjustments are now required to dial in the spatial portrayal to be even better). These skills are similar to those possessed by the best piano tuners. Many iterative adjustments of the relevant system parameters are required (since they all interact). It's a major task, even for an experienced system tuner with a keen ear, because the ultimate goal is so elusively Olympian, on a so much higher plateau than other surround sound systems can achieve.
Remember, we're not just talking here about being surrounded by merely the direct sounds of music, voices, and effects, as most other good surround sound systems can do. And we're not just talking about merely hearing some vague suggestion of the fact that some other alternative ambient space is being hinted at somewhere out there. Rather, we're talking about being convincingly surrounded by the indirect sounds of space itself, the magic of using merely a few loudspeakers within your small listening room to recreate a whole alternative space around you, and putting all the direct sounds from the recording (as well as you the listener) in that alternative space, so believably that your room totally disappears and you are totally transported aurally to the alternative venue - and so undeniably that, if you close your eyes, your ear/brain cannot deny that you are there instead of here.
One example of a good test for this is at 4:11 of the DVD entitled DareDevil, where the hero crashes to the floor of the cathedral. The sound of the crash impact with the floor is located in front of you. And, on most good surround systems, you can hear vaguely represented the fact that the recording contains some sort of rich echo after the crash, from the cathedral space. But, with our new system dialed in just right using these Arcam units, we experience the literal space itself of the cathedral, all around us, so that aurally we are undeniably there, with the well defined cathedral space, walls, and reverberation all around us, as our listening room totally disappears. It's a transforming and transfixing experience. You don't say Wow! You can't say anything. You can't move. You're not in this world any more, for you have been transported. All you can do is sit there, wanting to drink in more.
As noted, we had independently verified that these Arcam units are superb at the classic basic aspects of audio, such as transparency, resolution, and clean purity. This led to our natural hypothesis that these Arcam units are superb at mastering space precisely because spatial clues are so subtle and require the best transparency, resolution, and clean purity to be revealed. But we wanted to corroborate this hypothesis, by testing causality in the converse direction. So we then conducted further research experiments. To accomplish this testing protocol, we evaluated the Arcam AV8 preamp processor against some competing preamp processors. All were fed in turn by the identical signal from the Arcam DV27A DVD player. In order to test for causality in the converse direction, the idea was to first evaluate these competing units to see how well they did in basic classic sonic virtues like transparency, resolution, and clean purity (using high quality music and voice recordings in simple stereo) - and then see if their performance in reproducing space itself from good surround recordings would follow in line with what we had heard from their performance in the basic classic sonic aspects. If their spatial performance was indeed predictable from their performance in the basic classic sonic aspects, this would corroborate our hypothesis that the Arcam's dramatic superiority in mastering space itself is causally linked with its independently verifiable superiority in the basic classic sonic aspects.
Competing processor 1, a well respected high end brand, was pleasant sounding in reproducing high quality program material (music and voice), but there was slight veiling, and consequent loss of subtle information from this degradation of transparency and resolution. This information loss was audible even when using this processor in its most transparent, most direct mode, which bypasses all internal signal processing and uses the processor simply as a straight analog volume control stage.
Would this slight veiling, this degradation of transparency and resolution, affect this processor's portrayal of space, and how? Sure enough, this competing processor (even in its direct bypass mode) portrayed surround space as a vague halo of ambience, with poor localization of the diverse defining sonic characteristics of the original recording space and venue. Spatial cues seemed to be everywhere and nowhere at once, as if lost in a fog. Thus, this competing processor's basic information loss also lost the specific cues that were needed to believably recreate a realistic sounding spatial environment, leaving only a vague, unconvincing, foggy halo of ambience.
In contrast, when we switched to the Arcam AV8 under identical conditions, all the diverse spatial cues became beautifully defined. The alternative space itself suddenly and dramatically snapped into focus and into believable, indeed aurally undeniable, reality, all around us. This contrast demonstrated and corroborated our hypothesis that superior transparency and resolution (for all signal information), as we heard in these Arcam units, really are important for achieving superior portrayal of space itself.
What about the other classic sonic aspect we mentioned, clean purity? Clean purity implies low distortion. It's not intuitively obvious that clean purity or low distortion would be important for spatial portrayal, nor why it should be important. So it's worth investigating and discussing in some depth. To confirm our hypothesis about clean purity also being important to spatial portrayal, it would be ideal if we could test causality in the converse direction, on a competing processor that had good transparency and resolution, but which was compromised in clean purity. We could then first independently assess its problems with clean purity, predict what adverse impact this should causally have on spatial portrayal, and then see if indeed this competing processor's spatial portrayal was degraded, and degraded in the predicted ways. As it happened, competing processor 2 turned out to be a good candidate for probing this question.
Competing processor 2, also a respected high end brand, fared better than competing processor 1 in basic transparency for most of the spectrum, when evaluated on high quality music and voice. However, it evinced a different kind of sonic problem. It did not have the clean purity that the Arcam AV8 has. Instead, this competing processor added a little raspy distortion in the lower treble (and it did so even in when we used it in its most pristine mode, its direct bypass mode, bypassing all internal processing, so we were using it just as a straight analog volume control stage). This raspy distortion was of course somewhat ugly sounding in its own right, and it added a bright edge of coloration in the lower treble (which some na´ve listeners might mistake for better definition or clarity). Furthermore, this added rasp subtly smeared the original treble information in time, which degraded the individuation of treble transient information, and also filled in what should be the black background of intertransient silence with spurious garbage energy. This smearing obscured subtle sonic information that would otherwise be audible between musical transients - subtle information such as spatial cues from hall reverberation responding to the musical transient that has just occurred. Note incidentally that nonlinear distortion by definition creates new spurious energy at new frequencies, which means that by definition it creates new spurious energy at new times, which means that this spurious energy will fill in what should be intertransient silence with garbage, thereby obscuring subtle musical information and spatial cues that would otherwise be audible between properly individuated transients.
Now, what should this raspy distortion in competing processor 2 portend for its spatial imaging capabilities? Imagine first that one of your loudspeakers has a rubbing voice coil that produces a raspy sound, accompanying the music. You will hear that raspy sound as coming directly from inside the loudspeaker box. It won't be part of the portrayed image of the surround soundfield that should be suspended between all speakers (so well and so seamlessly that the loudspeaker locations aurally disappear), because this raspy sound was obviously not encoded as part of the recorded surround soundfield image of the alternative venue. Instead, it will be obviously localizable at and inside one loudspeaker location. Furthermore, this localized rasp will be very distracting to your ear/brain, and will thereby detract from the portrayal of the true, original surround soundfield image, because it is a hot spot of different, foreign sound emanating from an obvious location inside the loudspeaker box - and thus your ear/brain will constantly have its attention drawn to sound from within a loudspeaker box, so you won't be able to hear as well the surround soundfield image suspended between loudspeaker locations.
Imagine next that every one of your loudspeakers has a rubbing voice coil. The raspy sound will still be very localizable as coming from inside each loudspeaker box. In this case the plural raspy loudspeakers surrounding you will give you a kind of multi-mono. The effect will still be to destroy the portrayal of the originally recorded surround soundfield image suspended between loudspeaker locations, this time with localized rasps inside each loudspeaker box distracting your ear/brain from hearing the fragile surround soundfield image suspended between loudspeaker locations.
Then, imagine next that this rasp comes not from the voice coil, but rather from a piece of electronics of your system, perhaps from competing processor 2. This rasp still does not come from the recording, and was not encoded as part of the recorded surround soundfield image of the alternative venue. It is instead being newly added as a new extra sound by competing processor 2 (nonlinear distortion literally adds new sounds, called distortion byproducts, at new frequencies). And this added rasp is being fed as a mono signal to each loudspeaker, just as in the previous example, where each voice coil was rubbing and rasping in mono. Thus, these rasps will still seem to come from inside each loudspeaker box, much as the voice coil rasps did. Therefore, an electronic unit adding raspy distortion to each electrical channel would produce that distracting raspy noise as localized within each speaker box, and these multi-mono hot spots of distracting raspy noise energy at each speaker location would make it harder to for us to hear the encoded surround soundfield image that should be delicately and tenuously suspended between speaker locations. So, the whole surround soundfield would be degraded toward multi-mono, with hot spots of excess sonic energy located at or near each speaker location. Additionally, the smearing from the raspy distortion would further obscure the subtle imaging cues that allow music to be suspended in space between speaker locations, and also would further obscure any portrayal of the original venue's true space.
What would be the implications for spatial portrayal if we include such a piece of electronics in our system? What can we predict about the spatial imaging of a system after we insert competing processor 2? We can predict that the spatial portrayal would tend to be multi-mono. We can predict that there would be hot spots of excess raspy sounding energy localized as coming from inside each of the surrounding loudspeaker boxes. We can predict that, with our ear/brain distracted by the excess and raspy sounding energy localized within each loudspeaker box, it would be harder for us to hear any portrayal even of direct instrumental or vocal sounds suspended in the areas between loudspeakers. We can therefore predict that these instrumental and vocal sounds would be pulled toward the hot spots of energy crowded at each loudspeaker location, and would themselves be clustered in and near each loudspeaker location, instead of being in their properly imaged location, suspended partway between loudspeaker locations. We can also therefore predict that it would be much harder for us to hear subtle indirect information suspended in the areas between loudspeakers, such as the subtle sonic cues needed to portray space itself, to portray a believable alternative venue all around us, especially in all the areas between loudspeaker locations in our listening room. We can predict that the smearing from the raspy distortion would further obscure these delicate sonic cues needed to convincingly portray the space itself of the alternative venue. And so, finally, we can also predict that this multi-mono presentation would keep us aurally trapped within our small
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