elac debut 2.0 b6.2 Loudspeakers
Feel free to compare these small speakers against anything else that’s on offer, even if they’re two or three times the price!
Elac’s original Debut series, designed five years ago, was a true debut… and in more than one sense, because not only was it the first series of its type from Elac, it was also the first series designed for Elac by famous speaker designer Andrew Jones after he’d been hired by the famous German manufacturer to be its Vice President of Engineering. (Jones having previously been chief speaker designer at KEF… after having also worked at both Infinity Systems and Technical Audio Devices).
Despite the model numbers in this series changing only slightly, through the addition of a ‘.2’ to the various models (so the B6.2 we’re reviewing here is the successor to the original B6), the speakers are completely different, with new drivers, new cabinets and new crossovers. Speaking of which, it would seem that somewhere along the line, someone at Elac decided that adding a ‘.2’ to the end of the model number did not really give a hint of the magnitude of the change, so they also added ‘Debut 2.0’ as a prefix to the model number, hence the full (and rather difficult!) model name: Debut 2.0 B6.2.
THE EQUIPMENT
What’s new? Everything, as I stated in the introduction, but let’s start at the top, both literally and metaphorically. The tweeter in the B6.2 is a new 25mm ‘cloth’ soft-dome design that has a very wide roll surround. I don’t know why Elac says ‘cloth’ in its specification, because the material used is actually woven from pure silk which, although it’s certainly technically a ‘cloth’ is rather a fancy one, so I would have expected it to be described as such. Jones says this new tweeter’s frequency response extends to 35kHz, which is quite an achievement for a soft-dome design. Also new is the horn-loading (Elac calls it a ‘waveguide’) of the tweeter, which Jones says not only improves the tweeter’s dispersion, giving a wider ‘sweet spot’ but also ‘ eliminates the diffraction modes inherent in traditional box enclosures.’ Not that you can see the horn, because both the tweeter and the horn are totally concealed by an attractively shaped protective grille mesh… which is easily removable.
The bass/midrange driver in the B6.2 has a cone woven from aramid fibre (Kevlar is a type of aramid fibre trademarked by Dupont). The cone has a diameter of 118mm, but the Thiele/Small diameter is 132mm, giving an effective cone area (Sd) of 136cm². (The 165mm Elac quotes in its specification is the overall diameter of the driver basket.) Not only is the aramid fibre cone material new on the B6.2, the shape of the cone is also different, with Jones claiming that the new shape gives ‘ greater stiffness and improved damping, with the increased stiffness enabling
Elac’s Debut 2.0 B6.2 speakers are completely different, with new drivers, new cabinets and new crossovers
more flexibility in design to achieve a smoother, more extended low-frequency response.’
Although the cone itself is made from aramid fibre, the central dustcap, (which is fairly large, with a diameter of 50mm, suggesting that the voice coil is also 50mm in diameter, so rather bigger than the 25–30mm I would normally expect to find on a driver of this size) is made of Santoprene. The outer cone (roll) suspension is also made of Santoprene. (Santoprene is a dynamically vulcanised alloy consisting mostly of fully cured EPDM rubber particles encapsulated in a polypropylene matrix.)
The bass reflex port on the B6.2 is not new, it’s the same full plastic port that has both internal and external flares to reduce the possibility of chuffing that was on the original B6 model, but whereas on the original model the port was at the rear, it’s now on the front baffle… as you can see for yourself from the accompanying photograph. This means that you can now move the rear of the cabinet as close to a rear wall as you like, or push the speakers all the way back into a bookshelf or, indeed, recess the speakers into a wall if you like (technically known as ‘soffit’ mounting).
The main grilles on the Elac B6.2 are made from plastic that has been extruded in a honeycomb fashion, over which is attached black acoustically transparent cloth. Each grille has six plastic pegs that fix into rubberised sockets on the front baffle. I found the speakers sounded best without these grilles— and without the metal tweeter grilles as well, but the differences are not all that great and you may not find them audible at all. To find out if you can, put the speakers side by side, one with all its grilles on and the other with all its grilles off and, whilst playing a mono recording, use the balance control on your amplifier to switch back and forth between the two. If you can hear a difference, choose the configuration you prefer, and if you can’t hear a difference, listen to the speakers with all the grilles in place. Be prepared for the situation where you can hear a difference, but you prefer the sound of the speaker with all the grilles in place. Then you have a real win–win situation!
The speaker terminals on the rear are gold-plated, multi-way types that are recessed into a rather small plastic fitting. The size of the fitting makes it difficult to attach, say, bare speaker wires, but since it’s a connection you’ll only have to do the once, that’s OK. Otherwise, fit your speaker wires with banana plugs. The crossover network is attached to the rear of the rear terminal. It’s compact, with three inductors that are all cross-mounted, two of which are air-cored and one of which is mounted on the underside of the PCB, three capacitors (two bipolar electrolytics and a metalized polypropylene) and two five-watt cermet resistors to give a nominal electrical crossover frequency at 2.2kHz.
Presumably to keep costs down, the Elac Debut 2.0 range is available only in one finish, a not overly-realistic-looking vinyl wrap Elac calls ‘Black Ash’. Each speaker measures 196×375×268mm (WHD) and each one weighs 7.4kg.
Although Elac is headquartered in Kiel, Germany, the Elac Debut 2.0 B6.2 speakers are built in China, while Andrew Jones does all his design and development work at Elac’s R&D facility in Cypress, California.
IN USE AND LISTENING SESSIONS
The Elac B6.2 arrived for review at a time when one of my favourite spinners was a delightfully gentle and musically inveigling album by Australian guitarist Rafael Arden titled ‘When the Guitar Sings’. From the very first track ( Vous vouriendrez-vous), you’ll understand why it’s so titled, because Arden’s acoustic guitar has a truly ‘singing’ tone. Whether this is due to the guitar itself, or because Arden tunes his ‘A’ string to 528Hz rather than to the standard tempered scale’s 440Hz—or perhaps it’s due to a combina- tion of both—but the sound is amazing, particularly on the higher strings and their harmonics. The result was that when playing this disc, the air was alive in front of the Elac B6.2s… I would not at all be surprised if this album became one of those classic ‘demo’ discs you hear in showrooms (and at hi-fi shows) throughout Australia. All the works on the disc were written by French/Canadian composer Guy Bergeron who, according to his website, can usually be found ‘ live and acoustic at various events, hootenannies, bike rallies, pig roasts and drink-em-ups across New England.’ Arden is easily up to the technical demands of Bergeron’s sometimes difficult works, and despite the difficulties there are far less fretting and neck sounds to be heard than I might have expected… and when I did hear these sounds, the Elac B6.2s delivered them so accurately it was difficult not to imagine that Arden was actually in the room in front of me… an imagining helped along by the closeness of the recording.
In order to give the Elac B6.2s more of a heavy-duty workout I pressed the ‘play’ button on the cutely named ‘Tremolow’ which is the debut album from Brisbane’s own ‘The Creases’ which is out now on CD, vinyl and digital. Gabriel Webster’s percussion introduction to the opening track Answer To proved that despite its rather small cabinet and bass driver, the Elac B6.2s can deliver an impactful bass sound, with obviously solid bass to below 50Hz. I couldn’t hear any overhang at all with any of the percussion instruments. Listen too to Webster’s stick-work on the rims, plus the way the B6.2’s tweeter handles the highs when he’s taking it out on his cymbals. (The album notes specify this album should be played ‘ at maximum volume’— which is intriguing, but not something I’d endorse if you value your loudspeakers). The Elac Debut 2.0 B6.2s capture the depth and rhythm of Jarrod Mahon’s bass, particularly on Is It Love, but the recording of his bass is a bit variable, which is evidenced by listening to it on the previous track, Everybody Knows, so be prepared for some differences in reproduction from track to track that are due to the recording, rather than the speakers themselves. But simply the fact that such small, inexpensive speakers can be revealing of such differences in bass tonality is revealing in itself. The Elac B6.2s also delivered the total musical energy of this Brisbane four-piece in a realistically live manner, including with a fine grip on performance.
It didn’t take too long listening to some of my favourite female vocalists to hear where the Elac B6.2s really excel, and that’s right across the midrange, from the upper bass to the high treble.
The accuracy of the reproduction of the sound across the midrange is uncanny and the result is that the tonal quality of a singer’s voice is exactly the same no matter what notes she’s singing. Pitch accuracy is also perfect. For example, when I was listening to a piano arpeggio across the midrange, every individual note was reproduced at exactly the same volume, so in this case not only the tonal quality was the same, but also the volume. One of the vocalists I spent a long time listening to using the Elac B6.2s was Cat Canteri, who’s a favourite not only for her fabulous voice, but also because she’s a terrific song-writer, which you can hear for yourself on her latest album, ‘Inner North’, which is her most personal album to date. Her a capella intro to Pentridge Wasteland is beautifully emotive, then as the other instruments join in and the soundscape widens, the effect is mesmerising. Her vocal intimacy on Remember the Time is astounding, the recording of it perfect, and the delivery by the Elac B6.2s also perfection. And if her song Bridget Agnew doesn’t tear at your heartstrings, you’d better check your wrist for a pulse.
As I’d expect from a designer of the calibre of Andrew Jones, the Elac B6.2s proved to be very easy to drive, so you’ll get great sound from any amplifier—or AV receiver—you care to use, and they’re efficient enough that you’ll easily achieve high sound pressure levels in your listening room without taxing your amplifier’s output stage, even if it’s relatively low-powered.
CONCLUSION
Elac’s new Debut 2.0 B6.2 speakers are far better speakers than the original Debut B6 design they replace and also far better speakers than their amazingly low price would suggest. If you’re looking for small speakers, feel free to compare them against anything else that’s on offer, even if they’re two or three times the price. You’re going to be surprised! Jeffrey Tregiet Readers interested in a full technical appraisal of the performance of the Elac Debut 2.0 B6.2 Loudspeakers should continue on and read the LABORATORY REPORT published on the following pages. Readers should note that the results mentioned in the report, tabulated in performance charts and/ or displayed using graphs and/or photographs should be construed as applying only to the specific sample tested.
LABORATORY TEST REPORT
The various protective grilles fitted to the Elac Debut 2.0 B6.2 meant that Newport Test Labs had to conduct more than the usual number of frequency response tests in order to completely show the speaker’s frequency response under all configurations. The trace shown on Graph 1 below 1kHz is comprised of the averaged result of nine individual frequency sweeps measured at three metres with the central grid point on-axis with the tweeter
when using a pink noise test stimulus. The trace above 1kHz is the gated high-frequency response measured without any of the speaker grilles in place. It shows that the frequency response of the Debut 2.0 B6.2 extends from 50Hz to 35kHz ±3.5dB and that the response is quite linear, without any spectral skewing, indicating that the sound does not favour any particular band (or bands) of frequencies. You can see there are two points on the graphed response where the measured response dips slightly below the –3.5dB envelope (at 18kHz and at 26kHz) but the bandwidth is so narrow at both frequencies—plus that the dip at 26kHz also above the normal range of human hearing—that they can be overlooked for the purpose of giving an overall response rating.
You can see how the grilles affect the high-frequency response of the Elac Debut 2.0 B6.2’s output by looking at Graph 2, where the black trace shows the high-frequency response without any grilles fitted, and the red trace shows the response with just the metal tweeter grille fitted, and Graph 3, which shows the high-frequency response with just the metal tweeter grille fitted (red trace) and with both the metal tweeter grille and the main cloth grille fitted (blue trace).
You can see that fitting the metal grille over the tweeter moves the dip in the response from 18kHz down to around 16kHz, and increases the depth of the dip from 8dB to 12dB. Fitting both grilles (the blue trace) increases the depth of the dip at 16kHz to around 18dB and shifts its frequency up very slightly, but even more significantly introduces a dip in the response down at 10kHz, increases the depth of the dip at 26kHz, and adds additional dips in the response at 31kHz and 37kHz.
Interestingly, what’s probably the most audible of all these differences is actually the
seemingly innocuous 2.5dB-ish depression in the response between 2.5kHz and 6kHz.
Overall, the measurements made by Newport Test Labs would seem to suggest that the best and flattest frequency response from the Elac Debut 2.0 B6.2s will be obtained when no grilles are used at all, but the audibility of the different combinations should be determined by listening sessions, as the presence of two loudspeakers in different positions in the room—and the use of two ears—will result in a different ‘response’ than the ones shown, which were of course obtained using just a single loudspeaker and a single microphone.
The response of the Elac Debut 2.0 B6.2’s bass/midrange driver rolls off very cleanly below 110Hz at 18dB/octave to reach a minima at 46Hz. This minima coincides nicely with the maximum output of the bass reflex port, so the speaker is ‘classically tuned’. You can see (Graph 4) that the port’s output has a low Q, so that it’s just 6dB down at 33Hz and 85Hz.
The impedance of the Elac Debut 2.0 B6.2 design, as measured by Newport Test Labs, is shown in Graph 5. It looks mostly like a nominally 8Ω speaker, except that that dip in impedance at 200Hz to 4.8Ω means that under IEC 268-5 standards, the Debut 2.0 B6.2 design should be classified as a 6Ω design which is why Elac has done exactly this in its specifications.
As you can see, the impedance is relatively benign and should present no difficulties for any amplifier, with well-controlled phase angles (blue trace) and a rising impedance at high frequencies, which is important to ensure the stability and predictability of the output of Class-D amplifiers.
The minima between the two low-frequency resonances (the lowest of the two, at 32Hz, peaks at 50Ω and the higher, at 78Hz at 46Ω), is at 48Hz, indicating that you should not expect any significant output from the speaker below this frequency, so I would posit that Elac’s low-frequency specification of 44Hz is a tad optimistic.
The averaged in-room response (above 1kHz) is shown as the green trace in Graph 6. This is the trace that most closely shows what the human ear would hear when listening to music, and you can see that although it rolls off smoothly above 9kHz to be 3dB down at 14kHz and 6dB down at 20kHz, there are none of the peaks and dips of the direct on-axis response (black trace). This graph shows a system resonance at 650–700Hz whose effect is most obvious on the output from the bass reflex port, but also affects the output of the bass/midrange driver. However, as you can see from looking at the main frequency response immediately above, it does not appear to adversely impact that response.
Newport Test Labs measured the sensitivity of the Elac Debut 2.0 B6.2 design at 85dBSPL at one metre, for a 2.83Veq input using the lab’s standard test methodology. As noted on previous occasions, the particular wideband measurement technique used by Newport Test Labs discriminates against small bookshelf/ standmount speakers, because it necessarily takes into account extreme low-frequency output, so small speakers will always return lower SPL figures than larger ones, even if midrange efficiency is identical. That said, 85dBSPL is quite low… in fact a full 2dB lower than the average for all hi-fi loudspeakers (and a full 2dB lower than Elac’s specification), so if you regularly listen to music at fairly high levels, you should plan on driving the Debut 2.0 B2.6s with a fairly high-powered amplifier—one with a rated output of around 90/100-watts per channel. If you listen at more conservative levels, you could reduce this to around 60-watts per channel.
The extensive laboratory tests conducted by Newport Test Labs prove that the Elac Debut 2.0 B6.2 is a well-designed, high-performance loudspeaker. Steve Holding
The measurements suggest that the best and flattest frequency response from the Elac Debut 2.0 B6.2s will be obtained when no grilles are used at all