“A bunch of the boys were whooping it up at the Malamute Saloon.” All of the claims of huge breakthroughs over the years do bring to mind this opening line of Robert Service’s famous poem. But sometimes these claims of radical improvements that change what is possible in audio and offer new vistas of excellence… sometimes one or another of these claims is actually the unvarnished truth, not whooping it up at all, but a matter of straightforward fact. DALI claims that its Epicon Series speakers embody a new kind of magnetic structure that reduces odd-order harmonic distortion in dynamic drivers to the point of its being all but unmeasurable. Interestingly, the even-order harmonic distortion remains unchanged: the Epicons have low but not unprecedentedly low total harmonic distortion. But the odd-order parts are, they say, all but gone.
And the Epicon 6 speaks for itself on this matter: I do not think anyone listening to it, audiophile or no, would fail to observe how pure and liquid is the sound, how reminiscent indeed of the ultra-low harmonic distortion of electrostatics. Once heard, this liquidity is unmistakable and likely to be unforgettable as well. Lars Worre, the chief executive of DALI, explains the new magnetic structure in some detail (www.youtube.com/watch?v=PTPSelj4g8M), and I shall summarize the principles of it later. But the effect is surely heard independently of the explanation being offered, interesting though the explanation is. This is not something one has to talk oneself into hearing!
There is far more to speaker design than low-distortion drivers, of course. But driver behavior is fundamental. I shall go later into how the Epicon 6s perform in other aspects. But their low distortion already makes them not only interesting as a product but something of a landmark in audio history.
How the Reduction in Distortion Works
A driver consists of a magnetic structure surrounding a “voice coil,” the voice coil being attached to the part of the driver you see, the part that moves the air. The voice coil is moved by the magnetic force: When current goes through the coil, force is exerted on the coil and the coil is thus accelerated. And the force on the voice coil is ideally exactly what it should be as determined by the current flow in the coil. But in practice, the magnetic structure is usually made of metal. And the metal conducts electricity. So the coil with its varying current generates, via electromagnetic induction, current in the magnetic structure’s metal. This current in the magnetic structure in turn alters the magnetic field, inducing an unwanted and uncalled for extra force on the coil. These induced currents, “eddy currents” as they are called, are a source of distortion. The idea of the DALI driver is to get rid of them by making the magnetic structure effectively non-conducting so that eddy currents are prevented. [See also the discussion of driver eddy currents in my review of the Magico Q7 in Issue 229.—RH]
The eddy current problem occurs also in transformers, which is why laminated structures are used for them, the lamina being separated by thin layers of insulation so that current is unable to flow across lamina. A more extreme form of the idea of a non-conducting magnetic structure was developed by the Danish company Grundfos. Its idea was to make a material consisting of iron particles—so that it is magnetic—but to coat the particles with a non-conductive layer before forming the material by pressing the particles together. The result is in effect laminated in all directions at once and does not conduct.
The non-conducting magnet structure and eddy-current reduction is responsible for about half of the lowering of odd- order harmonics. The rest of the distortion reduction is the result of aluminum and copper rings within the magnetic material that create an optimally shaped magnetic field that is more linear. The rings also decrease inductance. Together, the unique magnetic material and the rings produce a magnetic linearity that remains constant regardless of signal current, signal frequency, or cone position.
This idea was in fact developed by Grundfos for high-speed electric motors, not for speaker drivers at all. But, fortuitously, Grundfos is close to DALI in Jutland in Denmark, about ten miles away, and after a while the subject of using the idea for speaker magnetic structures came up (the idea was actually suggested by Grundfos, according to Worre in the video link). Of course, some work was needed on how to carry this out, but the idea has a fundamental rightness to it that strikes one immediately. Like many really good ideas, once this one has been brought up, it seems entirely natural.
And what can one say but that DALI and Grundfos have made it work? In measured terms, the odd-order harmonic distortion, which has been widely observed to be the kind that sounds bad, is all but gone. People tend to think of distortion in speakers as arising from break-up of the driver cone, and a lot of work has been done on making cones so as to minimize distortion of this sort. DALI has addressed that here as well, with special wood-fiber driver cones, which seem to work admirably. But the distortion from the motor mechanism also counts, and here in the Epicon Series, this problem is addressed in a new way, as noted. And it does the job in listening terms as well as in distortion measurements. (The new structure is also said to minimize problems from magnetic hysteresis effects.)
The sonic effect is, as mentioned, immediately observable and extremely pleasing. Or at least one supposes that it is this one is hearing; that the speaker sounds unusually pure and liquid is definitely the case. The attribution to the new magnetic approach is less obvious, but I am prepared to take DALI’s word for it that that is the cause of the unique sound heard. And the measurements surely back DALI up.
The Sound Overall: The Frequency Extremes
So take it for granted—not that you will have any trouble noticing!—that the Epicon 6 has an unusually low level of perceived distortion, a kind of meltingly liquid sound that one does not expect to hear this side of Quads. There are, of course, other aspects of the sound to be discussed, though the perceived low distortion of the speaker already makes it of compelling interest.
Let me start with the frequency extremes. The DALI has an unusual high-frequency driver, comprising a dome tweeter that is rather larger than usual (29mm) surmounted by a ribbon tweeter to fill in the top of the top octave—and actually a long way beyond (ribbon drivers tend to go way on out there). The result is a very high level of perceived high-frequency clarity—you will hear a lot of the micro-detail so beloved of audiophiles, helped on by the ultra-low distortion all the way down, as already noted.
This speaker has resolution and clarity in spades. The idea of using two tweeters to cover different parts of the treble is not new—it goes back at least as far as the Spendor BC1. But it is surely carried out to good effect here as far as apparent clarity and resolution are concerned. Things like the high percussion in one of my go-to orchestral recordings, Rachmaninoff’s Symphonic Dances (Mata, Dallas, ProArte) sounded remarkably like real cymbal crashes, with the requisite micro-structure that is really there in reality and on the recording, but that can turn into an undifferentiated blur with less than stellar tweeters. In these terms, the high-frequency compound unit of the Epicon 6s is in the top echelon, one of the best. If the high end is anything like synonymous with high end for you, you will be very happy here as far as the intrinsic behavior of the unit is concerned.
The tweeter unit does follow the usual DALI practice of being somewhat hot on axis with the idea being that one listens somewhat off-axis to the highs. This typically is done to fill in the power response of the top end—the on-axis tip-up fills in some reverberant-field high-frequency energy, but the off-axis listening position gets a flat direct arrival. Fair enough if you want more highs in your reverberant field.
Here, however, you do not have to move very far off axis in any direction before the response really nose dives. The flattest axis is, I estimated, around 15 degrees off the frontal position. But get as far as 30 degrees off to the side, and there is a quite pronounced roll-off. And the top highs are also sensitive to vertical position, as one expects with a vertically oriented ribbon. This is all not as such a problem—just sit where you should (which is fairly low down as it happens). But less than ideally situated listeners will hear a non-flat response in the top as direct arrival. The pattern is somewhat complex and way off-axis, at 90 degrees (where of course no one sits), there is an odd whistle in pink noise for some reason, although this is not particularly important to music listening as such in normal positions.
Associated with the exceptional performance of the high- frequency unit is a very high level of perceived resolution. DALI has always believed in the importance of being able to hear detail, or so I have gathered (I used to live in Denmark and I have known the DALI people for a long time). And one certainly hears a lot of detail here. Even on familiar recordings, one is likely to become acutely conscious of inner details that were barely observed before and not brought so much to the fore. Inner parts are heard with great clarity. And complex textures unraveled. Of course, audio reviews say this kind of stuff all the time. But here it is really true.
Another aspect of this resolution is that the Epicon 6 seems to be truly free of any adverse effects from its cabinet. In a world where some designers feel the need to make speakers that weigh hundreds of pounds to get sufficient cabinet deadness, DALI seems to have done the trick with a cabinet of modest weight (66 pounds) and very elegant appearance, too. Admiration is called for! The cabinet not only looks elegant in a modernistic sort of way, it really gets out of the way of the sound completely. Listen to any complex music and you will be impressed at how much of the inner structure of it you can hear. Between the low distortion, the exceptional high frequencies, and the lack of cabinet sound, you will hear what there is to hear.
At the opposite extreme, the bass is extended for a speaker this size, with a -3dB point of 35Hz so; in room, bass goes down very far if not absolutely down to 20Hz. The bottom of the orchestra is covered with ease. There is a lot of bass! Truth to tell, in my room of modest size (approximately 18′ x 22′) there was a bit too much. But it was well-defined and one got a real feeling of the low end power of the orchestra or of rock bass.
A lot of the excitement of music of all kinds is carried in the bass, and the Epicon 6 could sound exciting, indeed. The big whomps in the Rachmaninoff mentioned above gave the real feeling of bass power that orchestras have live. And the over-all warmth helped to fill in the floor dip that tends to develop with floorstanders. The bass may be a little much technically, but musically it was much to the good.
No wimpy sound here, no making the great orchestral masterworks of the Romantic era sound like recorder ensembles or making rock sound as it sounds on a table radio. When Richard Strauss and Dvorák and Mahler and Wagner—or Pink Floyd, for that matter—let you have some bass excitement, you really get the point here. (The Epicon 6 is ported with two large ports in the back). I guess you get the idea that I liked this!
The Epicon 6s present a spacious sonic image, and they vanish convincingly into the soundfield that they generate. Set up pointing down the room straight ahead or only slightly toed- in, the focus of individual images is less definite than with some speakers that are intended to be listened to with the speakers pointing straight at you.
If I may be permitted an aside and a suggestion for experimenting: This spatial character is presumably in part attached to the increase in high frequencies as one gets closer to the axis, meaning that with the un-toed (or only slightly-toed position) sideways head movements increase the top end slightly from the speaker that the head moves toward. This setup is the opposite of the idea used by Ohm and others (and originally suggested I think by Spendor and the BBC) of arranging that such a head movement would diminish the highs, thus creating a kind of time/energy trading that stabilizes and focuses images. Of course, the high end has pretty much forgotten about this, and in particular doing this tends to narrow the “soundstage.” (There is a school of thought that claims that the “soundstage” is often in good part an artifact of a certain lack of image focus in the classical sense, ditto dimensionality in most cases.) If you want image focus in the classical sense, you can get it here by over- toeing the speakers, that is by bringing the flat axis to you by toeing the speakers so that the axes cross at a point considerably in front of you! You might not like this, but then again you might, and it is worth a try. And since the Epicon 6s are apparently intended to be heard slightly off-axis, you have the option here, either way.
In any case, whatever your spatial preference, the Epicon 6s are set to deliver it in the right setup. Experimentation is the key!
Overall Balance and the Midrange
As has been pointed out in TAS from the beginning, the heart of music tends to be in the midrange, and, to face the fact straight on, the midrange of the Epicon 6 is somewhat pushed back. In particular, the 1kHz to 2kHz octave and a bit above and below sound rather down in level. The speaker as a whole seems almost to exhibit some version of the “smiley face” EQ once so popular in the days when people routinely manipulated recordings— and audio systems—with analog EQ devices. This balance is in particular contrast with what seems almost to be a fad currently among speaker manufacturers as a whole to push the 1–2kHz region forward somewhat. Both sides of this have their points: Bring 1–2kHz up and the sound comes “out of the box” and certain types of vocal material are flattered. Pull 1–2kHz down and there is a nice recession of the image, distancing over- recorded, too-forward material.
Ultimately, however, to my ears, the midrange needs to be neutrally balanced (I am not a fan of the fad for pushing it forward, either). Whatever flatteries of some type or another one can get by having a bit too much or, in the present case, too little of the 1–2kHz octave, one pays at least some price in natural timbre. In particular, broadband music does not quite sound as it should on the Epicon 6s. It can sound attractive but it never comes across as completely correct in timbre.
Of course, one can EQ this region up and flatten the whole response. The speakers then sound better balanced. But midrange EQ of speakers really works best when it is a matter of very small tweaking of a balance with which one is basically happy to begin with. Making major shifts in balance by EQ is a tricky matter. The main point is that when the measured response of the Epicon 6 was flattened out, the sound changed a lot. This sort of broadband balance-change is really fairly major, though it may look small on a graph. It changes the sound of the music quite a bit.
The 1–2KHz suckout must have been a deliberate decision on the part of DALI, and I think many people will like it. So much material in the world is over-recorded that a bit of backing away from it can be all to the good. But the exact sound of instruments really is altered here. And even the apparent volume of notes can shift. On Moravec’s Debussy collection on Vox, one could notice in careful listening the slight droop in volume as he ran from below on up through the recessed range to the very top notes (which are higher than that, being 4186Hz), with the top notes coming back up in level.
This is not to say that the speaker is colored in the resonant sense. Actually, it sounds very smooth and non-resonant. What it does not sound is exactly flat.
While you may well like this, you should observe the effects carefully when you audition the speaker to be sure that you do.
The DALI Epicon 6 is an extraordinary speaker. In high- frequency performance, in perceived resolution, and in absence of cabinet effects it is in the top echelon and it really does make one wonder about the heroic measures that have come to be the most common approach to obtain these goals. Clearly a lot of thought has gone into this speaker, and avoirdupois has been kept under control without giving up any of the resolving power noted: no cabinet problems, but moderate cabinet size and weight. And most striking of all, the Epicon 6s really do seem to have crossed a barrier in low distortion in dynamic-driver speakers. This is truly historic. And I hope other driver manufacturers will look into licensing the patent from DALI. Once heard, never forgotten.
With all that said, you still have to listen for yourself as with any speaker, to the exact radiation pattern and tonal balance choices here. The Epicon 6s involve a distinctive approach on these matters and whether that approach pleases you you’ll have to decide for yourself. But in any case, this is a speaker that everyone ought to hear. Things this important do not come along very often. Congratulations on those low-distortion drivers are very much in order. In the words of Schumann writing about the music of Chopin: “Hat’s off, gentlemen. A genius.”
SPECS & PRICING
Type: Floorstanding bassreflex loudspeaker
Driver complement: Two 6″ bass/mid wood fiber cones, one 29mm soft textile dome, one 10 x 55mm ribbon
Crossover frequencies: 700Hz, 2550Hz, 15kHz
Frequency range: 35Hz to 30kHz
Maximum SPL: 110dB
Nominal impedance: 5 ohms
Weight: 66 lbs. each (net)
Dimensions: 9.1″ x 40.3″ x 17.4″
Price: $13,495–$13,995 (depending on finish)
The Sound Organisation (U.S. Distributor)
159 Leslie Street
Dallas Texas 75207
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