"It makes one wonder why all speakers are not made this way"
The front baffles of the Baron D300 is still a maze of odd angles, oddly-positioned speakers and ungainly acoustic blankets. Luckily, however, said front baffle is completely obscured by an acoustically transparent black grille cloth, which is stretched over a metal frame fixed to the cabinet.
Most people will be familiar with this "sock" design approach to speaker cosmetics. It was originally introduced in England in the early 70s in an attempt to cut the costs involved in finishing speakers in timber veneers, and also to reduce the requirement to import exotic, endangered rainforest timbers. In the case of the Baron, one suspects that cost reductions were only incidental to Duntech's use of a sock grille. In fact my guess is that the primary reason is simply that the sock neatly hides the unattractive front baffle from sight - a perfect matching of form to function!
If you could see the baffle, what you would see would be a stepped design, with two 210mm woofers mounted in front of two 100 midrange units which, in turn, are mounted in front of a single 25mm soft fabric dome tweeter, whose voice coil is attached via a butterfly assembly and surrounded by magnetic fluid. An artists' impression of the speaker array is shown in Figure 1.
The 210mm diameter of the woofers is only nominal. In fact, the overall diameter of the basket is 215mm, while the diameter of the cone and roll surround is just 186mm. The same goes for the midrange drivers, which have an overall dimension of 104mm, but a cone/roll surround diameter of just 81mm. Both the woofer and midrange drivers use cast magnesium baskets. The midrange drivers have double magnet assemblies.
This physical arrangement of drivers is intended to create simulated point-source radiation. For example, because the two woofers process the same information, anyone seated in front of them will tend to localise the sound as issuing not from the woofers, but from a point equidistant between the two woofers - that is, directly in the centre of the front baffle.
Likewise, the sound from the two midrange drivers will also be localised as being midway between the two drivers - also directly in the centre of the front baffle. And the tweeter, of course, IS directly in the acoustic centre of the front baffle. The result is that the total sound image produced by the speaker can be localised directly at the tweeter.
When you think about it, the driver arrangement used by Duntech is incredibly obvious - after all, it reflects the way the whole stereo illusion is created in the first place: that is, when you listen to your left and right channel loudspeakers and both are processing information that is identical in phase and level, the illusion is that the sound is issuing not from the left and right loudspeakers, but from directly between the two speakers, right in front of the listening position. The Duntech arrangement merely makes use of this illusion in the vertical plane as well as in the horizontal plane. In fact, the concept is so obvious that it makes one wonder why ALL loudspeakers are not made this way!
Which only leaves the problem of why the front baffle is stepped. The steps are simply to ensure that the path lengths from each driver are equal, so the sound from each of the five drivers arrives at the listeners' ears at the same time. According to Duntech, the ideal listening position; that which ensures that the sound from all drivers is in phase, is between three and four meters. Obviously, one's ears should be at the exact height of the tweeter if you are to take advantage of the point-source radiation concept and, in the case of the Barons, this means your listening chair should be of a height that positions your ears 95 cm above the floor - though in practise, small variations are of no real consequence.
Looking back over what I have written,and looking up at the Barons in front of me as I write (and 'up' is the operative word!) it occurs to me that all the foregoing may have given the wrong impression of the speakers' appearance. As you may be able to tell from the photograph, they are certainly not unattractive. The top and base of the speaker are finished in a black satin gloss, and the grey trim-strips fitted where wood meets sock provide welcome contrast. Undoubtedly Duntech has done the best it can with the cosmetics, but I venture to suggest there is not too much anyone can do to disguise a speaker which stands 1.44 metres high!
Although the speaker appears visually 'square' it is actually deeper than it is wide: 355 mm compared to 268 mm. Also, it is not advisable to attempt to carry a speaker on your own - each cabinet weighs almost 45 kg! However, once you have unpacked the speakers, attached the hardened steel spikes and got them upright, the speakers can be maneuvered quite easily by one person.
Normally, when reviewing loudspeakers, I like to pull them apart to confirm manufacturers' claims. Unfortunately, this was not possible with the Barons, due to the unusual method of construction. According to the specifications, the enclosure walls are built from 18 mm custom-wood and are internally damped to prevent resonances and cabinet vibrations.
The rear panel uses gold-plated, bi-wire input terminals which accept banana plugs, spades or stripped wire. The (-) and (+) terminals are on standard centres, so it is also possible to use dual Pomona fittings. The crossover, which is a first-order type, uses metallised polypropylene capacitors, ceramic resistors and low-loss, air-cored inductors. It consists of separate high-pass and low-pass sections, without common earths, so this means passive bi-amping is possible, should it be desired. Not too much is said about the internal cabling, but the comprehensive Owners' Manual suggests the cable is 'high purity copper wire containing up to 648 individual strands, with an acoustically dead outer insulation and outstanding electrical, mechanical and acoustical properties.'
According to Duntech, the frequency response of the Baron D300s extend from 45 Hz to 20 kHz ▒ 3 dB when measured at a distance of 3.5 meters on the tweeter axis. This is an unusual and difficult place to measure, but accurately reflects the response which will be heard when listening. (Most speaker responses are measured at a distance of one metre - a distance too close for auditioning).
Efficiency is rated at 92 dB SPL for an input of 2.83 V - nominally one watt. Unlike the frequency response, this measurement is made at a distance of one metre. It is quite a high sound pressure level, and means the Barons will produce significant output with low-powered amplifiers, though Duntech itself recommends a minimum amplifier power output of 40 watts RMS per channel.
The impedance varies between 3 and 6 ohms across the range 20 Hz - 20 kHz, so Duntech has rated the Baron D300 design at 4 ohms. The fact that the impedance dips to three ohms dictates that you should ensure that any amplifier driving the Barons has the ability to deliver current, since this will be required when the impedance gets low.
Duntech's specifications include a heading titles 'Pulse Coherency Factor' which is basically a measure of propagation time error between the various drivers. According to the specifications, propagation time error of the Baron D300s is less that 10 ÁS, because of the vertical array and the time alignment.
There is an interesting comment in Duntech's brochure which states: 'It may be argued that (a deterioration in) waveform and pulse quality is unimportant with respect to producing a loudspeaker that sounds good. There is an element of truth in this. It is possible to design a "good-sounding" loudspeaker which exhibits inferior phase response and pulse dispersive tendencies.' The brochure then goes on to say: 'The real difference is between good or pleasant sound quality and truly accurate sound quality.' (My bold type.) This, I think, is the nub of what John Dunlavy tries to achieve - he strives for accuracy above all else.
It is, perhaps unnecessary to state that the Duntech Baron D300s speakers work best in medium-to-large rooms, but I will, just so there is no doubt. Once of the reasons is simply that the speakers work best when they are well clear of both side and end walls, which means a minimum of a metre from both. And once the speakers have been positioned in this fashion, you then have to allow a minimum of three metres of clear space in the direction of the listening position - all of which means that any room in which the Barons are placed must be at least four metres long.
In practise, I discovered that in my room, a listening distance of 3.5 metres was preferable, and that the best listening position was 1.5 meters from the rear wall. Also, I found it was better to toe the speakers slightly towards the listening position. If you try to duplicate this positioning in your room, aim for an angle midway between having the speakers pointed directly down the room and pointed directly at the listening position.
On the subject of speaker positioning, Duntech's manual is one of the best I have seen on the subject, with four pages of instructions and diagrams showing three different set-ups in a 'typical' room. It is one of the best treatises I have seen in an owner's manual.
The second reason you need a large room is because, in my opinion, small rooms simply cannot contain the masses of delightful sound which issue from the Baron D300s. In a small room the Barons merely sound good: In a large room, they sound magnificent. This has, I think, to do with the nature of sound. A symphony orchestra sounds wonderful in a well-designed concert hall, but I doubt once would sound very good in the average lounge-room - even if all the members managed to squeeze in! I have also noticed the phenomenon with choirs. Large choirs into small halls just do not go. At one stage I had the Barons playing in my office and, although they still sounded good, they did not convey the same sense of excitement as they did when I set them up in my largest listening room.
And, make no mistake, the Baron D300s are exciting to listen to. Every sound they make makes you wish they'd make more sounds just like it. It seems almost churlish to dissect the soundfield, but just for the record...
The stand-out feature of the Barons is the stereo imaging. It is so stable that if you threw bricks at it, it would probably break. The height of the speakers, and the arrangement of the drivers, means there is never any sense of doubt about where a performer (or a performer's instrument) is located. It did not matter whether I was listening to small ensembles or to orchestral works - it was just as easy to point at the air and position a flautist or a bass guitarist as it was to position a harp or the precise location of the kettledrums.
I listened particularly carefully to a live recording of a private performance of Mozart's Requiem, which had been recorded with multiple PZMs. On most speakers, this recording is a disaster in terms of imaging. Auditioned via the Baron D300s, the various sections of the choir snapped into focus, and it was even possible to place the soloists with relation to the orchestra and the choir. I'm not just talking about image width, but also image height and depth - it's all totally realistic.
If the imaging is the stand-out feature, the bass response must come a very close second. It's awesome. More important, it is seamlessly matched to the midrange so there is never any sense of separating one from the other as instrumental lines cross back and forth across the crossover point. There is a reassuring solidity about the bass performance from the Barons yet never once did they sound boomy or overpowering - even with recording that I knew were somewhat on the bass-heavy side, thanks to the heavy hand of a record producer.
I am beginning to really appreciate Piere Verany's Digital Test CD (PV 788031/32) - particularly the bass on Track 10, an exert from Rimsky-Korsakov's Scheherazade. Listen to the introductory drum roll, as just one example. Vierne's 1st Organ Symphony (Track 12) is also a revelation, though I must admit that I find this track a trial, since I find the constant background hiss from the organ bellows is a constant distraction.
David Hykes' Harmonic Choir (Ocora C.558607) continues to be one of my test pieces for ambience and for high frequency performance and imaging. Auditioning the Barons, I feld as though I had been transported to the Abbey du Thoronet and placed directly in the centre of the hoomi singers - an unreal experience. One of my new test pieces is Philips' new DDD compact disc, number 4111402. This is a recording of Gregorian Chants - ten from Propers as well as the complete choral office for the Feast Of The Immaculate Conception. The sonorous male voices are reproduces beautifully on the Barons - no undue chestiness or midrange peakiness here!
Thinking I'd take an auditioning session from the sublime to the ridiculous, I gave Madonna's The Immaculate Collection a spin and was pleased and gratified to find that Duntech's Barons can disco with the best of them. Encouraged, I moved on to a Kraftwork (now there was a band which was far ahead of its time) disc which rarely gets a spin. The Barons handled the heavily-layered, metallic synthesiser constructions as if they had been specifically designed for the job.
By this time, I was deliberately looking for weaknesses in reproduced performance, because all that was issuing from the listening sessions was a rave review. Surely the Barons must have a weakness? If I were to be extremely picky and were told I must pick a fault, I'd suggest that the extreme top-end leaves a little to be a desired. The tweeter is smooth and trilling, but sometimes fails to punch completely through the wall of sound in the upper and lower mids.
You should especially note that the speakers will only operate properly when driven by a good-quality amplifier, one which can really deliver goods into 4 ohms or even less. To double-check this, I did something I would not normally do, and connected the Barons to a midi system (which I will leave unnamed). I was disappointed with the result. The midi system had insufficient power or punch to allow the Barons to perform at their best. I'd even suggest that the 40 watts RMS per channel recommended by Duntech is a little on the low side unless you listen only at very low levels. My suggestion would be an amplifier with an output in the region of 80-100 watts per channel. Even if you normally listen only at low levels, I can assure you that once you have listened to the Baron D300s, you will have an inescapable urge to increase the volume!