Up to 84% in savings when you subscribe to The Absolute Sound
Logo Close Icon

Begin typing your search above and press return to search. Press Esc to cancel.

GamuT Superior RS5 Loudpeaker

GamuT Superior RS5 Loudpeaker

Now that we are all happily reading—as I hope—The Absolute Sound’s Illustrated History of High End Audio, Volume One: Loudspeakers, it is natural to think of speakers under review in historical context. In capsule form, speaker design in the era since the introduction of the long- playing record has gone through these stages: the box speaker era of the 1950 and 1960s; the planar, both electrostatic and planar-magnetic, era of the late 1960s and the 1970s and 1980s; and then in recent decades, perhaps rather surprisingly, an era of return to box speakers, albeit floorstanders rather than stand- mounted or bookshelf models of the earlier days. Of course there have been exceptions all along. But it is striking to note how much the later chapters of the book are about floorstanding box speakers.

Two things happened here to cause this return to boxes. One was that dynamic drivers improved and improved a lot. There were fine drivers in the past, but they were hard to make. Cones had to be “doped” by hand, tweeters had to be laboriously pair- matched, and so on. These problems are largely something of the past.

A second development was the increasing use of exotic cabinet construction. The BBC designs and their offspring had dealt from decades ago with the issue of cabinet sound via their damped thin-wall enclosures, starting at least as early as 1968 with the Spendor BC1/BBC LS3/6. But the industry, especially in the U.S., began more recently to be obsessively interested in deadness of cabinets. Some of the result involved truly heroic measures—the Rockports come to mind as do the Wilsons, the Wilson line having arguably initiated the trend.

But a funny thing happened on the way to dead cabinets.

People began to observe, some people anyway, that dead cabinet speakers sounded to them, well, dead. The BBC had already pointed out that increasing rigidity pushed such resonances as there were up in frequency. Their approach was to use relatively flexible cabinets but to damp the resonances, which were at rather low frequencies and thus were less audibly objectionable. In effect, one had to match the amount of rigidity with the right kind of damping. Rockport’s constrained-layer damping was another effective approach used later on where rigidity was higher than in the BBC designs. But outside of those theoretical considerations, the idea somehow reappeared that in musical terms there might still be some reason to allow the cabinet to be less damped and to participate in the sonic picture more.

This is not an easy matter for an outside observer to consider definitively. After all, one can hardly take a review sample, remove the drivers, put them in a different cabinet, and go from there. What is not hard to check is that cabinets matter. The Microscanner devices to absorb cabinet energy (one of the tweaks that actually did something—no plastic dots of negligible mass but a real device to divert vibrational energy into non-audible forms) really did change the sound. Opinions on whether they changed it for better or worse might have varied from person to person, but change it they did. Nonetheless, a definitive estimation of the effects of cabinet sound in any one speaker—that is hard to get.

Like the Sony AR1s that I reviewed enthusiastically in Issue 214, the GamuT Superior RS5s use the cabinet as part of the sound. In fact, in my estimation they do this even more than the Sonys. Like the Sonys, they have a wood cabinet, rather than a particle-board one, with the idea being that the natural resonance of the wood will be integrated into the sonic picture. And the natural resonance is given what seems to be quite free play here in the GamuTs. Rigidity enthusiasts have tried to claim that cabinet sound is always distortion, but of course there is no reason why this should be so if cabinet sound is done correctly. The approach is not unreasonable—just tricky to pull off. No one wants to go back to the buzzy cabinets of old table radios—and no one is. The idea of letting the cabinet participate sonically is serious, whether one agrees with it or not. And plenty of serious people are pursuing it.

GamuT Superior RS5 Loudpeaker

There is a certain difficulty involved in analyzing what is going on here because one’s basic reaction to a speaker is dominated by frequency response and radiation pattern considerations— things which are only indirectly connected to the way the cabinet is made, though the shape of the cabinet has definite effects. So all one can really do is to describe the speaker’s “first-order” behavior—frequency response and radiation pattern—first, and try to infer what secondary effect the cabinet has on the rest.

Perhaps it does not really matter what causes what. Only the final sound is at issue for the consumer. But people should once and for all disabuse themselves of the idea that total absence of cabinet sound of any sort is some sort of Platonic ideal. An open mind is desirable here, as elsewhere, this situation being rather complex.

What the GamuTs Try to Do and Why
Lars Goller, the designer of these speakers, was very forthcoming about what he was aiming at, in the cabinet design in particular. Let me try to summarize for you what he said as I understand the picture. The set of ideas embodied in the cabinets of the GamuT arose from a general program, to some extent developed jointly with DALI’s Hotter Bak, of looking at what limits the resolution of speakers. The first round of this general investigation by DALI some time ago led to the idea of having drivers that avoided stick/slip friction at low levels. (My write-up of it for TAS can be read here: regonaudio.com/Tact%20and%20Dali. html.) The next and more recent stage was to look at cabinet effects from the same viewpoint. What was the cabinet doing to low-level signals? In particular, as the sound died away, was the cabinet preserving the decay correctly?

In principle, damping does not make this go wrong—not if damping remains linear at low levels. A linear damping process changes phase and frequency response but would not alter the correct decay behavior as such. According to Goller, however, research determined that, in fact, damping was non-linear when the levels became low enough. (Linear throughout this discussion means without distortion, not flat in response. People in audio journalism have taken to saying linear when they mean flat in response. I am saying linear in its true technical meaning of being a linear system, whether flat or not.)

This possible non-linearity is not something that is true of necessity—theoretical viscous damping is a linear process for instance. But Goller says that in practice, damped panels become non-linear at low signal levels.

So the idea of the GamuTs was to use rather less damping than usual, with the intention of preserving the natural and presumably recorded decay of sound. Also, as noted previously, wood rather than particleboard was used, this being regarded as having a more musical sound. To avoid coloration, the resonances of the quite lively cabinet are tuned to different frequencies. This is verifiable directly. Bang on the middle of the enclosure with a knuckle and you get an F, bang on the top and you get a C (more or less). By comparison, knock on a BBC damped-wall enclosure and you get an essentially un-pitched sort of thud with rather little specific frequency perceived at all. Knock on the walls of the Rockports, say, and you get nothing much at all. [Editor’s note. GamuT sent this clarification regarding the cabinets: “The description of the RS5 cabinet is not entirely correct, as it is described as lively. This is probably due to the fact that one only ‘sees’ the outer 12mm layer. The total board, however, is actually 28mm thick, and consists of an inner part made from 16 layers of 1mm veneers, the outer part is 12mm thick and made from six pieces of 2mm veneers. We apologize greatly for not having pointed this out more precisely.”]

The composite result from the GamuT approach is supposed to be a sound that is not overtly colored by pitched resonances— multiple resonances with different frequencies will sound less colored than a single resonant frequency for the whole cabinet— but at the same time “life” and correct decay are supposed to be preserved by the comparative absence of damping of the enclosure. Incidentally, the cabinet and crossover design must be taken as the justification of the price, since the drivers probably account for only a small part of the cost. The drivers are high- quality, and made by ScanSpeak to GamuT’s specifications. GamuT then modifies the drivers by impregnating the cones with a “natural oil.” Goller has compared this to the strings on a Stradivarius versus the violin as a whole, the violin being presumably the cabinet. And certainly the cabinet does function here as a musical instrument, in a sense. It plays a large role in the design thinking.

It all sounds a bit theoretical, but before you ever hear the speakers, just knocking around on the enclosure does give you the distinct impression that here is something new and different. And Goller, while he has theoretical justification, also appeals to the idea that there is something intrinsically less musical about damped sound than (distributed) resonance. The theoretical picture is a little indefinite because in linear-systems theory a (minimum-phase) system that rings equally at all frequencies, that has completely distributed resonance, does not in fact ring at all. But the idea in the GamuTs is to get sort of halfway there, to distribute the resonances enough to have low coloration but to retain the liveliness of minimal damping. That is my impression of what Goller is getting at, anyway. Apologies for any possible misrepresentation—it is not easy to describe what amounts to mathematical matters in informal terms without losing precision.

 

The Sound
Let me go straight from all these generalities to the completely specific. The first thing I listened to was Mahler’s Das Lied von der Erde, the recording engineered by Marc Aubort, performance by the Cincinnati Symphony, conducted by Walter Susskind. This is not to my ears the absolute top of the pile sonically among the long series of Aubort/Nickrenz masterpieces of recording, because the Cincinnati venue lacks the acoustic magic of Powell in St. Louis and the Minnesota hall where their Minneapolis recordings are done. But it has even so the characteristic Aubort virtues of natural sound and unconstrained dynamics. (Presumably the greatness of the music does not require detailed comment.) And the performance is fine. I am fond of this recording and I have listened to it a lot.

On the GamuTs, it surely exhibited new aspects. The dynamic liveliness was extraordinarily in evidence, and the micro-texture of instruments—the reediness of reeds, for example—was extra-strongly presented, giving in a certain sense more realism. And one heard the decay of the hall well. But the recording sounded peculiar. While the male voice in the opening “Drinking Song of the Sorrow of the Earth” does usually sound quite close to the microphone pickup, here he was considerably further forward than usual. And the orchestral sound also was midrange- pushed in a way quite different from what I am accustomed to on this recording so familiar to me. At the same time, the higher frequencies seemed somewhat suppressed. While the words were clearly understandable when, for example, the singer repeats “ist mehr wert” (“is worth more”—he is saying that a cup of wine is worth more than the kingdoms of the world), he positively bites the words, so strong is his enunciation. These are the lines just before the second of three enunciations of the darkness of life and death (“Dunkel is das Leben, ist der Tod”), and the singer quite properly wants to emphasize the point. On the GamuTs, the singer is closer to you than usual, but he is not singing the words so bitingly. (Slightly shameful confession: Paige and I often say “Dunkel is das Leben” as a sort of joke, a German version of “That’s the way it goes.” No disrespect to Mahler or the great Chinese poem he is setting, of course—humor is one way to deal with life, even though in Das Lied the line is anything but humorous.)

Then I went on to Korngold’s Die Tote Stadt on Naxos. I seldom use this music—or, for that matter, the Mahler—for audio evaluation. Both are too beautiful and too powerfully emotional for concentration on sound per se to seem appropriate. But I just felt like hearing this music, and the recording is again deeply familiar to me. As opera recordings go, this one is more natural in perspective than usual, especially in the orchestra. But again, everything seemed more forward. Not perhaps unattractive at first, but surely atypical for this recording. And to my ears, this balance was not ultimately completely satisfying. The soprano voice just did not sound really naturally balanced. (The same had been true of the contralto female voice in Das Lied.)

Next I listened to the Reference Recordings Rutter Requiem to check out bass. The bass was in fact impressive for a speaker of medium size. The deep pedal tones came through precisely without any sense of strain, even at quite high levels, and with fine pitch definition. This is a ported speaker but according to GamuT, the port design has been especially carefully done to avoid any sort of noise. This has worked in audible terms and the “alignment” seems very good—the bass is strong but well-defined and without any sense at all of “one-note” emphasis.

Again one felt that the mids were projected, presence somewhat recessed and the bass slightly detached, though there seemed little sign of the kind of deep, even cavernous, dip in the 100 to 300Hz region that tends to plague floorstanders. Rather there was just a generally lower level of energy compared to the mids above that region. The overall effect was a lot of midrange with good bass that was not quite continuously attached, and with a fine and detailed, albeit (on-axis) slightly exaggerated, high treble, again not really continuous with the midrange. This was not a question of hearing drivers separately at all—that does not happen—but rather of perceived balance.

The Measurement Situation and What it Means
Now be assured that these observations about balance arose entirely from listening and prior to measurements of any type. I was not talking myself into anything from looking at graphs. But when I did look at graphs, I surely saw confirmation about the balance.

I sent the in-room measurement, with its shape agreeing with the description just given (about 3-4dB too much energy in the 500Hz to 1kHz octave) to Lars Goller for comment. His response was interesting, indeed. He said that yes, that was indeed a characteristic result for that type of measurement and that the speaker had been designed that way because the result interacted with the radiation pattern of the speaker to be “subjectively linear” (linear in this case meaning flat). There is naturally a change in radiation pattern in going from the fairly large (7″) mid-driver to the small and wide pattern tweeter. And the balance of the speaker had been set to take that into account.

Dealing with this change in pattern at the transition from the midrange driver to the tweeter is of course a problem that turns up in almost all multi-driver speakers. Only a tiny midrange driver avoids this (while having problems of its own). A little deviation in on-axis response to ease the transition in listening terms is almost always done, since otherwise “tweeter flare”—the wider pattern when the tweeter comes in—makes the tweeter sound separated from the midrange. But usually this is a subtle matter, a slight easing of on-axis response, not a wholesale dumping down of the presence range. I suppose “subjectively linear [flat]” is just that, subjective, but the suppression of the presence range and the weakness of the 100 to 300Hz range—though that is not extreme—makes to my ears the midband stand out in an obvious way.

The Overall Picture
No one supposes that any particular speaker is perfect, even if there were universal agreement on what a speaker ought to do to be perfect, as of course there is not! Thus the designer and the reviewer are up against a conundrum. Progress has by definition to make things different from before. A real improvement in speaker design will make recordings sound different from what one is accustomed to. But at the same time, if they sound too different, then the whole idea of a speaker as a communication channel—a way to hear what the people who made the recording intended—is undermined. In some way, one wants to hear what was intended but somehow to hear it a little better in one way or another.

The same characteristic sound appeared in all my listening. Things were lively, with a strong sense of realistic dynamic life. And spatially the speakers did well, with convincing imaging and presentation of surrounding space. One heard well into the recording’s venue. The GamuTs as I hear them are setting out to let one hear better certain aspects of the sound recorded—to have cleaner, smoother decay with resolution preserved at the tail-ends of sounds, to give more insight into the recording’s decay characteristics and thus in particular into the acoustics of the recording venue, and to have a certain kind of dynamic life. I think that the unusual design principles that are apparently directed at these goals show not just promise but a good bit of realization here, to the extent that one can separate such perceptions from frequency-response matters. In these ways, the speakers do sound unusually life-like. And for many people, this may be enough. But at the same time the GamuTs also have a definite character to their sound that is independent of these positive characteristics and that to my mind is distracting musically.

People apparently vary on these matters. One often reads audio reviews nowadays where what the speaker actually sounds like in tonal balance and tonal coloration terms is hardly addressed. It is as if people had lost interest in the obvious aspects of the sound, the most obvious things about a speaker being its overall balance and its tonal colorations or comparative absence thereof. Such reviews can go right by those matters to worry about what one might have supposed were second-order, secondary things, interesting though these might be. But personally, I find it hard to get by substantial perceived errors in the obvious aspects of tonal balance and tonal character, which are after all what a speaker really sounds like in the most basic sense.

The GamuTs are an embodiment of some creative and very interesting ideas in speaker design. I think everyone seriously interested in speaker design ought to give them a serious audition. Whether you find them compelling as a possible purchase, at their substantial price, will probably depend on how you react to their midrange-forward perceived tonal character. But in any case, if you are interested in speaker design, you need to hear what can be done not with a dead, damped cabinet but with a cabinet that has controlled liveliness as I think of it. The GamuTs are a fascinating speaker design, whether or not you find the balance to your liking.

SPECS & PRICING

Type: 2.5-way, bass-reflex floorstanding speaker
Drivers: Two Scan-Speak 7″ mid/woofer drivers, one Scan- Speak Revelator double-ringradiator tweeter
Frequency response: 31Hz–60kHz
Impedance: 4 ohms, nominal
Crossover points: 550Hz and 2.25kHz
Dimensions: 226mm x 1210mm x 575mm
Weight: 54kg
Price: $30,000

GamuT Audio
Siggårdsvej 2 DK6818
Denmark
gamutaudio.com

Audio Skies (U.S. Distributor)
(310) 773-4435
info@audioskies.com

Robert E. Greene

By Robert E. Greene

More articles from this editor

Read Next From Review

See all

Adblocker Detected

"Neque porro quisquam est qui dolorem ipsum quia dolor sit amet, consectetur, adipisci velit..."

"There is no one who loves pain itself, who seeks after it and wants to have it, simply because it is pain..."