added sonic information that made the cannon shot sound and feel far more accurate, but it also seemed to effectively subtract out acoustic information, seeming to reduce the audibility of the conventional subwoofer's wildly flapping ringing misbehavior. The conventional subwoofer was still wildly flapping, as we could see visually, since it was still being driven by the same signal, but the sonic garbage from this misbehavior seemed reduced when we added the TRW into the system.
       How could this be so? We hypothesize that the huge, continuing, correct positive pushing pressure from the TRW, as the cannon shot's explosion signal continued to push positively, acoustically swamped (in room pressure), and thereby offset, the smaller negative sucking sound of the conventional subwoofer's ongoing ringing, during the negative portions of its negative overshoot (region 2) and ringing (region 3). In effect, the TRW with its huge positive DC energy was biasing the large (but smaller) AC ringing misbehavior of the conventional subwoofer, raising it upward so that this AC ringing stayed entirely positive (class A instead of class B, if you will).
       And it makes obvious sense that a signal that stays positive, as it should from this cannon shot, sounds more accurate and less spuriously garbagy, even if it does vary somewhat in its positive amplitude, than a signal that rings between positive and negative, alternately pushing air into the room and sucking air out of the room, as the conventional subwoofer does via its misbehaving spurious ringing, when used alone without the TRW. We'll see below two further examples where the TRW's huge energy, DC biasing ability provides yet further sonic benefits.

D. Music

       Again, we'll start with the most obvious, expected sonic differences, and work toward the unexpected, which actually turn out to be of even greater sonic benefit, to even more of your music.

D.1. Pipe Organ

       First out of the gate was of course a pipe organ recording, the famous Vikings track from the Reference Recordings' CD Pomp and Pipes. Organ notes are similar to sine waves, so they can elicit and probe different bass performance aspects than transient signals do (our further sonic tests below employ transients). Some organ pipe notes on this track are very low in frequency and very high in bass energy. Through just the state-of-the-art conventional subwoofers, these organ notes sounded quite powerful and impressive, as good as we've ever heard them from conventional subwoofers. But, with the TRW added, these same organ notes took on whole new qualities and dimensions. Yes, these notes went even deeper and were even more powerful with the TRW, by a dramatic margin. But, even more impressively, rather than merely hearing the bass and slightly feeling the bass, as happened with the conventional subwoofers, with the TRW added your whole body shook with the bass, as though the organ pipe were vibrating the very planet and the entire atmosphere.
       Furthermore, with the TRW the quality of the organ pipe's bass became entirely different, and much more true to life. A large organ pipe moves a huge volume of air, but at very low pressure. The TRW makes bass energy in this same way, so the TRW accurately replicated this same bass quality, with the same relaxed effortlessness that the giant organ pipe itself evinces. The giant organ pipe can afford to be relaxed, even while it is producing a huge amount of bass energy, precisely because it is so large, and the TRW can do the same, since its effective radiating diaphragm area gets so large at low bass frequencies.
       In contrast, the conventional subwoofers created a wholly different kind of bass quality for these organ pipe notes, the high pressure sound of a small volume pump madly pumping as hard as it can, and this sonic quality is all wrong for pipe organ bass, and indeed is all wrong for virtually all bass musical instruments. Anyone who has heard these bass musical instruments live can instantly hear this dramatic difference in bass quality, and can instantly recognize that the TRW is very right, whereas the conventional subwoofer is very wrong.

D.2. Plucked String Bass

       Our next musical test was a plucked string bass, as heard on Midnight Sugar (Three Blind Mice) and on Red Mitchell, Home Suite (Caprice). Now we're testing with transients, which constitute the bulk of all program material, and which demand good subwoofer performance in the time domain as well as the frequency domain (sine waves and pipe organs are less demanding, only demanding good performance in the frequency domain).
       With the TRW added, the bass plucks had a much more solid foundation, as though they were grounded and rooted in the earth itself. In contrast, with the conventional subwoofers alone, the bass plucks sounded more superficial, without a solid foundation. Also, the resonance of the bass viol's huge wooden sounding board and cavity was reproduced by the TRW with the correct bass quality, again the effortless, low pressure bass that a large diaphragm produces. In contrast, the bass quality from the conventional subwoofers alone again had that forced, high pressure quality, totally alien to the actual bass sonic quality produced by a live plucked bass.
       The biggest sonic surprise, with the plucked string bass musical selections, were the sonic differences in boominess vs. tightness, and bass definition. Since the organ notes above were essentially steady sine wave tones, they did not probe or reveal the transient response differences between the TRW and conventional subwoofers. But the plucked string bass is indeed a transient, so the differences in bass transient (time domain) response, between the TRW vs. the conventional subwoofers, came to the fore and became sonically very important.
       With the conventional subwoofers alone, the transient response sounded decent enough, as good as we have heard from other conventional subwoofers, but in direct comparison to the transient response with the TRW added, it was obvious that the conventional subwoofers were still very boomy, loose, woolly, and poorly defined in their transient response, with lots of lingering overhang. We have come to accept this kind of poor transient response and sound from our subwoofers, because we have never heard anything really different or really better. But, with the TRW added to the system, bass transient response took on a whole new character on these plucked bass notes, a character that was obviously far truer to the actual sound of live plucked bass, with vastly better tightness, definition, and absence of artifacts like overhang and boom. Suddenly the plucked bass sounded real and live, not like an artificial hi-fi system.
       It's interesting to note that the TRW achieved this dramatic improvement in bass transient response when merely added to the system, with the conventional subwoofers still playing as before. We suspect that this is another example, where the TRW's huge acoustic output, of the correct transient signal which goes down to DC, acoustically overwhelms and offsets the boomy, ringing, higher frequency AC misbehavior from the conventional subwoofers. Of course, the tight definition and lack boom, in the system's bass transient response, would naturally be improved even further by leaving the TRW in but taking the conventional subwoofers out, and this is precisely what we did for our second round of listening tests, discussed below.

D.3. Piano

       The third musical test employed piano notes with dynamic attack, such as on that Midnight Sugar track. These piano notes have largely midrange and treble spectral energy, so we are moving up the musical scale, from the bass organ notes and the bass notes of the plucked bass viol of our previous comparisons. Because the piano is a percussion instrument, the attack of each note is a singular transient, and therefore actually contains spectral energy down to DC, even though the sustain of the note is nominally in the midrange or treble. Thus, in theory at least, the extent of the TRW's reach down to DC, and its full energy and accurate transient response down to DC, should be of some sonic benefit. But what exactly would these theoretical sonic benefits actually sound like, if audible at all?
       With the TRW added, each piano note became much more solidly grounded, since it now had a solid low frequency foundation for the whole note, in the low bass content actually contained in the attack transient.
       Also, since each attack transient, even for high frequency piano notes, contains infinitely dense spectral energy all the way down to DC, it excites the resonances of the piano's huge wooden sounding board, which can clearly be heard from a live piano. With only the conventional subwoofers playing, we heard each strike transient of the hammer hitting the metal piano strings, but we could not clearly hear the piano's wooden sounding board at all. But, with the TRW added, the sonic contribution from the piano's sounding board was clearly evident. Moreover, this sonic contribution had all the right sonic qualities, to sound just like a live piano. With the TRW, the sounding board clearly had a natural wooden sound, which nicely and naturally counterbalanced the steely sound from the hammer attacking the metal strings. And, with the TRW, the powerful energy emanating from the huge sounding board had that effortless, relaxed quality that naturally comes from a large diaphragm radiating low pressure acoustic energy.
       Some of the sonic benefits, realized by the TRW on these midrange and treble piano notes, were quite unexpected. Each note became much more coherent, much better focused in time, with all parts of the note and all parts of the spectrum sounding together. And, with all parts of each note's energy cohering in time and being focused at the same time, the piano's dynamic range also increased dramatically, with a much higher crest factor.
       How and why does the TRW achieve these further sonic benefits? All conventional subwoofers, with their high reactances at low frequencies, are inherently dispersive, scattering the energy of the transient attack to different, erroneous phases and to various different points in time. But the TRW is inherently free of reactance at low bass frequencies, so it does not scatter this transient energy over time, and instead plays it all at the same time, so it coheres in time, with far superior focus and dynamics.
       Additionally, with its far superior reach to DC, the TRW takes the very low frequency spectral energy actually contained in the piano's attack transient, and plays it at the correct full level, for the correct long duration, without declining (as conventional subwoofers do in region 1), and without negative overshoot that cancels (via sucking) the positive pushing energy (as conventional subwoofers do in region 2), and without the spurious ringing that effectively cancels itself out with alternate pushing and sucking (as conventional subwoofers do in region 3).
       Thus, the TRW achieves and reproduces the correct pedestal or foundation, at full correct amplitude and for the full correct duration, that is required to support the midrange and treble spectral content of the piano note, and is required to reproduce the correct sonic waveform for the whole piano note, including all its spectral portions. With the TRW, the piano became a solid, three dimensional, palpably real entity in front of us, even on an upper frequency note that one might think would not involve a subwoofer at all. Without the TRW, without the pedestal and waveform accuracy on this same upper frequency note, the same piano sounded instead like a non-solid, two dimensional phantom being artificially reproduced by some hi-fi system.
       Note too that the deep bass content of the initial attack transient, the pedestal foundation for the whole note, actually lasts for the entire temporal duration of the whole note, including the sustain temporal portions with midrange and treble content, and it lasts so long precisely because it is and represents such low frequency information. Therefore, the low bass content of the initial attack transient actually becomes a crucial pedestal and foundation for the whole piano note's waveform, not just for the initial attack temporal portion.

D.4. High Frequency Violin Pluck

       Continuing to move up the frequency spectrum, our last musical test was those high frequency violin plucks, such as those a little over a minute into the fourth movement of Bartok's Fourth String Quartet (Chilingirian on Chandos). A violin, in contrast to all the previous musical instruments, has small dimension, with a small sounding board and small cavity. Thus, these elements would not be producing any low frequency information to speak of.
       But what about the attack transient of the pluck of the high frequency string itself? Theory tells us that this attack transient actually contains spectral energy all the way down to DC, and our measuring microphone confirmed this. But there's only a small amount of spectral energy at very low frequencies. So of course we had to find out if perchance the TRW would make any perceivable sonic difference on this high frequency violin pluck, when added to massive conventional subwoofer systems that already boast full response down to 16 Hz.
       And our desire to test this was more than idle curiosity. Because, if the TRW made a sonic improvement even on this high frequency violin pluck, that would mean that the TRW is musically important and beneficial for virtually all music, at all frequencies, since virtually all music involves transients.
       The TRW did indeed improve the sound of these high frequency violin plucks, and everyone in the room heard these improvements. The most obvious sonic improvement was that the pluck became much more solid tactile, and believable. This was probably because the low bass energy of the initial transient acquired with the TRW the correct waveform, to become the correct pedestal for the high frequency portion of the overall waveform, so it thereby made the overall waveform perceivably more accurate, and more coherent and focused. The high frequency violin pluck with the TRW sounded much more like a real violin pluck, on a solid, tactile, three dimensional instrument you could reach out and touch, while without the TRW it sounded like a typical artificial hi-fi reproduction, with a more phantom-like, less palpable existence.

E. Extreme Makeover, TRW Edition

       Finally, adding the TRW brought even further sonic improvements that were a complete surprise. The following surprising benefits were heard on all kinds of music, at all frequencies, including midrange and treble frequencies. The same benefits were heard by everyone in the room, and they were consistently heard as, in disbelief, we repeatedly switched he TRW in and out of the system, shaking our heads at these surprising sonic improvements we kept hearing.
       Without the TRW, the system sounded like a great quality but nevertheless artificial hi-fi reproduction. There was some sense of strain at midrange and treble frequencies, some artificial hard glare at these frequencies, some temporal smearing of what should be individuated and articulated details, some loss of transparency and of black intertransient silence from the fact that the temporal smearing of energy created masking and filling noise at the wrong time, and some phony brightness at these upper frequencies.
       These are all sonic symptoms of distortion. And they all magically disappeared when we switched the TRW back in. It was as if the TRW waved a magic wand over the sonics of the whole audio system, did an extreme makeover, and gave us a whole new audio system. Here are the specific improvements we all heard.
       With the TRW included, the sense of strain disappeared, including at midrange and treble frequencies, and the music emerged naturally and effortlessly.
       The artificial hard glare disappeared, this change sounding almost as though we had changed from a mediocre solid state power amplifier to a great tube power amplifier, for the system's main loudspeakers. Musical instruments sounded warmer, mellower, more natural, and far more realistic, far more like the sound of real live instruments and far less like artificial hi-fi reproduction.
       The temporal smearing disappeared, and details became much better individuated and articulated, but without any artificial sharpness. With the disappearance of the temporal smearing, high frequency details and transients became much more focused, coherent, and dramatically faster, while also actually becoming more delicate (which is a sure sign of true speed, since each transient declines quicker after its peak, hence is over with sooner, hence sounds more delicate).
       Also, with the disappearance of temporal smearing, black intertransient silence improved, and overall transparency and clarity dramatically improved, since there was no longer spurious noise energy (from the temporal smearing) obscuring musical details and filling in what should be the black background silence, against which musical details should be audible in clear relief.
       Finally, the phony excess brightness also disappeared, resulting in a much more musically natural tonal balance and sonic quality.
       As one example of the above sonic contrasts, a hard strike upper frequency piano note, played on the system without the TRW, sounded strained, with artificial glare and excess brightness, and we could hear only the metallic sound of the strike and the glare. When we added in the TRW, the same piano note sounded natural and relaxed, without strain, and the artificial glare and excess brightness and excess metallic quality all disappeared. And, with these spurious distortion artifices gone, the whole system became more transparent, so for the first time we could clearly hear the subtle, true to life sounds of the wood and the felt materials in the piano hammers, as they struck the metal strings. Suddenly, with the TRW, the piano sounded physically and musically real, as an instrument that actually uses wood and felt and metal to make its sounds, not just metal (as the system without the TRW sonically suggested).

E.1. Puzzle about Possible Cause

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