F. Summary of Relevance

       We have now seen that the extreme low frequency capability of the TRW is assuredly relevant, and indeed doubly relevant. It is relevant and crucial for accurately reproducing virtually all live transients recorded onto our program material, all of which actually have frequency content extending all the way down to DC -- not to mention the extreme low bass from synthesized sound effects that are directly electronically recorded onto film soundtracks, without any intervening microphone. And it is relevant to humans' ability to sense extremely low bass frequencies in all these transient acoustic events, down at least to .1 Hz. Thus, it is crucial for any subwoofer worthy of the name to be able to play, and play accurately, and play at full volume levels, all the way down at least to .1 Hz. No conventional subwoofer comes even close to this, so they are in fact not true subwoofers at all. The TRW does meet this subwoofer requirement, fully and effortlessly. So, once again, the TRW is the only subwoofer.



Part IV: The Sound of the TRW

       We tested the sonics of the TRW in two distinct setups, first as a low frequency supplement to a system that already had a full array of conventional subwoofers, and second as the sole subwoofer mated only to main loudspeakers extending down to 40 Hz. We'll describe all our findings for the first setup first, and then later our findings for the second setup.
       The pre-existing conventional subwoofers in the first setup were very capable, indeed spectacular, as conventional subwoofers go, representing the best that the state of the conventional subwoofer art can achieve. There were actually three conventional subwoofer systems, with huge driving cone area among them, and the largest conventional subwoofer being a monster in a huge enclosure that extends down to 16 Hz. The test protocol was simple. Play the system, including all these monster conventional subwoofers, without the TRW, then add in the TRW as a supplement, and note the sonic differences. We of course played a wide variety of program material, ranging from extreme low frequency effects on film soundtracks, to various kinds of music, including the high frequency violin plucks from Bartok's Fourth String Quartet, discussed above as an example of high frequency musical transients.

A. Film Soundtracks

       Let's start with the most obvious, and most expected, sonic differences, and then move toward the more unexpected sonic differences (which actually turned out be even more dramatic and important). The TRW's manufacturer had prepared a burned DVD with excerpts from many films, containing a wide variety of low frequency sounds and sound effects.
       Some of these sound effects were in effect very low frequency tones or rumbles, well below 20 Hz, which lent a palpable atmosphere to the room or space where the film action was taking place. Because they were well below 20 Hz, as proven by a live real time spectrum analyzer that was monitoring all proceedings, these sound effects were virtually or totally inaudible via the full system with the giant conventional subwoofers, but they were clearly audible and clearly felt physically when the TRW was added into the system. Very impressive, and just what one would expect.
       Some of these sound effects were in effect gated bursts of sine waves, like the dinosaur footfalls in the Jurassic Park series. Here too, the deeper frequency reach and greater power capability of the TRW shone forth clearly. These sounds were impressive by normal hi-fi expectations from the conventional subwoofers alone, but, when the TRW was added into the system, the efforts of the world's best conventional subwoofers suddenly became wimpy and unimpressive in comparison.
       With the TRW in the system, these sounds induced a feeling of primal fright in our gut, whereas with the huge conventional subwoofers these same sounds were just entertaining noise. With the TRW, you don't just hear sound effects, you also feel them (far beyond what even the best conventional subwoofers can do), so they become much more involving, more exciting, more terrifying, more dramatic. The physical feeling imparted by the TRW is so accurate to the sound effect being represented that the effect becomes very believable, so it physically brings you into the scene visually portrayed on the display (far more convincingly than those shaking theater chairs do).

A.1. Bass Transients from Soundtracks

       We've saved the best, of film sonics, for last. The TRW is superbly impressive, and far superior to conventional subwoofers, when reproducing sound effects that, like the above, involve sine waves or gated pulses of sine waves, with bass energy around 3 to 5 Hz. But, when it reproduces bass transients, which reach all the way down to DC, the TRW is not merely superior or impressive, but instead gives you a wholly different type of experience, totally unlike anything you have experienced before on this planet.
       It is bass transients which most strikingly reveal the fact that the TRW is a wholly different kind of subwoofer, not merely a bigger, better, badder subwoofer. You see, the sound effects above, based on sine waves with energy primarily only in say the 3 to 5 Hz region, result in strong output from the TRW but essentially no output from conventional subwoofers, so from these one might conclude that the TRW goes lower and louder in bass (which of course it does do), but does nothing else special (which would be untrue).
       However, bass transients dramatically bring out the very best and most unique behavior from the TRW, since they show off the TRW's unique sonic abilities all the way down to DC (an infinite number of octaves below 3 Hz), plus they show off TRW's unique time domain accuracy. In contrast, bass transients bring out and highlight the weakest and worst behavior from conventional subwoofers, because, unlike the 3 to 5 Hz sine wave sound effects above, transients do get the conventional subwoofer to respond, and (as discussed above) conventional subwoofers respond with all kinds of phony sounding spurious sonic garbage, including overshoot and ringing and boomy overhang, even while they totally fail to convey the true solid impact that a bass transient should have.
       Thus, bass transients highlight the very best (and most unique) sonic assets of the TRW, while highlighting the very weakest and most garbagy behavior of conventional subwoofers. And therefore bass transients most clearly demonstrate that the TRW is wholly different in its fundamental nature from all conventional subwoofers.
       There are many different kinds of bass transients on film soundtracks, from slamming doors to shotgun blasts. And we could spend hundreds of words, telling you about the wholly different sonic experience the TRW gives you, as directly compared to the world's best conventional subwoofers, from these many kinds of bass transients. But instead, we can sum up all of this in three simple words.
       Master and Commander.
       The cannon shots in this film are very potent, and very realistic (we have a handy sonic reference standard in the live mortar fire we hear at a nearby military base). A cannon shot emits tremendous positive pushing airflow, which just keeps pushing, for a rather long time. From this, you hear and feel a tremendous thud, which hits your whole body and presses in upon it. Then, unlike the quick kick in the stomach from other kinds of transients, the positive pushing airflow pressure from the cannon shot just keeps on pushing at you, keeping your stomach compressed inward. This is probably the closest acoustic analog to the step test electrical signal we used above, to probe the very limits of bass performance, since the step also suddenly rises to a higher airflow level and then just keeps on pushing, for a long time. The bass from a real cannon shot is also surprisingly tight and dry, not boomy or woolly.
       The TRW's reproduction of these cannon shots is thrilling, and superbly realistic. Since the TRW can inherently output huge amounts of airflow, and can effortlessly do so forever, with its response down to DC, it is intrinsically perfectly suited for accurately reproducing these cannon shots, just as it is for accurately reproducing the similar step test signal, which is the standard for examining a woofer's true capabilities at their limit.
       Through the TRW, these cannon shots have such huge, huge, huge volume impact that your whole body will be limp with disbelief, that any loudspeaker of any kind, indeed anything short of a live cannon, could achieve this. And, through the TRW, the pushing pressure from each cannon shot continues in time, just as from a live cannon, rather than prematurely falling limp as it would from every other transducer that did not have full response down to DC. And, through the TRW, each cannon shot sounds tight, dry, and well defined, just like the real thing, since the TRW has essentially perfect transient response.
       In contrast, the cannon shots through conventional subwoofers, even some of the best in the world, was a whole different story, when heard without the TRW. The initial impact was like being weakly patted with a powder puff. What little positive pressure there was, quickly died away, as these conventional subwoofers wimped out on the sustaining of pressure and went into premature decline (region 1) in the time domain, which is correlated to their premature bass rolloff in the frequency domain, at the relatively high frequency of 16 Hz (which is an infinitely higher frequency than zero Hz or DC). Their bass quality on these cannon shots sounded woolly, loose, boomy, and poorly defined, in complete opposition to the TRW, because the conventional subwoofers were doing their negative overshoot (region 2) and AC ringing (region 3) spurious misbehavior, rather than accurately tracking the input signal.

A.1. i. Spurious Garbage from Conventional Subwoofers

       And we've saved the worst sonic offense for last. Just after their initial powder puff impact on the cannon shot, the conventional subwoofers went into sustained wild oscillating ringing, frantically flapping and pumping back and forth, in totally spurious misbehavior that was not at all representative of anything in the input signal, of anything in the actual sound of the cannon shot. This totally spurious mad pumping misbehavior sounded just like what it was, spurious garbage totally unrelated to the true sound of a cannon shot (it sounded even worse than a boomy bass overhang, which at least is related to the original bass sound).
       What's going wrong here, so dreadfully wrong? As discussed above, conventional subwoofers spuriously ring, in their own cycling pattern unrelated to the input signal commands, in region 3 of their time domain response to a transient, and this ringing is especially bad, in both amplitude and sustained temporal duration, with vented bass subwoofers.
       In this example of the cannon shot, this sustained spurious ringing was even worse than usual (on other kinds of bass transients), and was especially obnoxious sonically. That's probably because the input signal from the cannon shot is a transient with sustained energy, and massive amounts of sustained energy, and energy that is very near DC in frequency (as the cannon shot keeps up its positive push for a sustained duration). Thus, the cannon shot input signal keeps pouring massive energy into the conventional subwoofer at a frequency near DC. But the conventional subwoofer is inherently an AC device, and does not know how to accurately play this incoming energy that's near DC. But this massive incoming energy, near DC, keeps on coming for a sustained time, from the cannon shot. So, what can the subwoofer do with all this massive, sustained incoming energy near DC? It has to do something with all this incoming energy.
       So the conventional subwoofer does the only thing it can, the only thing it knows how to do with incoming energy that's lower in frequency than the subwoofer system's resonance frequency. The conventional subwoofer dissipates this massive incoming energy by madly ringing at its resonance frequency, the pattern of this ringing being dictated by the conventional subwoofer's physical parameters, and not at all by the input signal, so that the ringing signal output is totally spurious garbage, which is totally unrelated to the commands of the input signal.
       In effect, the conventional subwoofer takes in all the incoming energy below its resonance frequency (which it can't reproduce at the correct frequency), and converts this lower frequency energy into ringing energy at the higher frequency of its system resonance. And, because the lower frequency, near DC, energy from the cannon shot just keeps on coming temporally, the conventional subwoofer can do nothing but keep on ringing temporally, frantically flapping in a totally spurious way, and madly pumping as hard as it can, trying to dissipate all this incoming energy, and thereby creating the maximum amount of spurious garbage that it can, for a sustained period of time.
       The conventional subwoofers are alternately pushing air into the room and sucking air out of the room, over and over, for a long period of time, whereas the true input signal from the cannon shot should be continually pushing, into the room air and into your body and ears, for this entire time. No wonder the conventional subwoofers sounded so obnoxious, and so phony, on these cannon shots!
       And remember, this misbehaving conventional subwoofer just happens to be one of the biggest, best, baddest, most expensive subwoofers extant (even more expensive than the TRW), a subwoofer that has been widely praised as the best in the world heretofore. This conventional subwoofer is indeed a praiseworthy, excellent design effort, as conventional subwoofers go. But it is still a conventional subwoofer, so it is still inherently trapped by all the physical handicaps and roadblocks discussed above. Thus, it is clear that even the very best design efforts, in conventional subwoofer technology, pale (and fail badly) in contrast to the TRW, with its radically different, indeed opposite, type of subwoofer technology.

B. Fundamentally Opposite Kinds of Subwoofers

       A key reason we went to great lengths, discussing above how the TRW is fundamentally opposite to conventional subwoofers, was to make it clear that the TRW is not just another rung up the same ladder -- as the ever bigger and better conventional subwoofers have been, when they succeeded one another as highest on the ladder. The TRW employs a wholly different, radical technology for subwoofers.
       And the key to the TRW's unique advantages, and sonic superiority, and lack of handicaps in handling low bass frequencies, is that the TRW's different technology is not only radical, but also inherently opposite to the fundamental technology of conventional subwoofers, so that the TRW's technology intrinsically handles, with effortless ease and with great energy, key subwoofer tasks that are difficult or impossible for conventional subwoofers.
       There have been many review articles (including ours) praising past conventional subwoofers as the best yet, many reviews using descriptive words similar to the words we're using here to praise the TRW. Why should you believe these same descriptive words now, any more than these words were believable then when applied to conventional subwoofers, but are suddenly inapplicable now to these same conventional subwoofers?
       Several reasons. First, we directly compared the TRW sonics to one of the very best conventional subwoofers, representing the pinnacle of conventional subwoofer technology, and the sonic differences and contrasts were more than night and day.
       Second, the sonic differences were not merely a matter of degree, with the TRW merely extending deeper in bass frequency and playing bass louder (which it does do) - rather, the TRW also gives you a whole different kind of bass experience, and (as we'll see below) a whole different kind of musical experience.
        Third, reviewers and audiophiles alike have had to accept over the years that the sound of conventional subwoofer bass was the best bass that audio reproduction technology could produce. We heard and praised incremental improvements in this same type of reproduced bass over the years, as being further rungs up the same ladder. But now, even a brief listen to the TRW makes it obvious that this is a whole new kind of bass reproduction, sounding dramatically different from even the best conventional subwoofers, and sounding much more like real live bass (for those who know the sound of live bass sounds). Suddenly, with this dramatic sonic contrast, so obvious in direct comparison, our ears become instantly educated, that a whole new kind of bass is possible from reproduction systems, and that the old fashioned kind of bass we had to live with and accept before, from conventional subwoofers, is hopelessly inadequate, and actually sounds very wrong, in the many ways we have chronicled here for you (so that you too can learn about this wholly new kind of bass).
       Fourth, as we've learned from the extensive discussion above, the TRW technology is so fundamentally opposite to conventional subwoofer technology, in so many ways, which allow the TRW to inherently handle a subwoofer's responsibilities so capably, that there's no way that conventional subwoofer technology can catch up to or approach the TRW's wholly different, dramatically superior sonic performance.
       It literally is a whole new ball game. And all conventional subwoofers, even future designs, will still be limited to the intrinsic physical handicaps and roadblocks of their technology.

C. TRW Reduces Boom from Other Woofers

       Incidentally, it's worth noting that, on the above cannon shots, adding in the TRW not only

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