Elac Adante AF-61 loudspeaker

German manufacturer Elac had a significant North American presence in the 1960s and '70s, primarily with its Miracord automatic turntables. While it eventually disappeared from the US market, Elac never ceased to be a player in Europe, where it eventually shifted its primary focus from turntables to loudspeakers.

When Elac decided to reenter the US market a few years ago, its success was hardly assured. Faced with hundreds of brand names and thousands of models fighting for attention, it hired veteran speaker guru Andrew Jones to improve the odds. In his previous work, first for KEF and then for TAD and Pioneer, Jones had built a solid reputation on designing well-received, cost-no-object speakers as well as high-value budget designs.

The results have been startling. Beginning with the aptly named Debut line, now in its second generation, and following up with the Uni-Fi series, Elac and Jones have made serious inroads in the sales of budget loudspeakers, reviving not only the Elac name but also an audio market too long smitten with blindingly priced speakers.

Nevertheless, Elac models have followed at higher, if not sky-high, prices. The company's current flagship line, Adante, comprises the AS-61 bookshelf model (and matching, optional, and recommended stands), the AC-61 center-channel, the SUB3070 subwoofer, and our subject here: the Adante AF-61 tower speaker ($5000/pair).

Design
Andrew Jones has used concentric drivers since his early years with KEF, and continues to favor them in all but his least expensive designs. For Elac they first appeared in the Uni-Fi range, and both the stand-mounted Adante AS-61 and the floorstanding AF-61 employ them as well.

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In a concentric driver, the tweeter is positioned at the apex of the midrange cone, the latter acting as a waveguide for the former. The main benefit of a waveguide is to reduce the tweeter's dispersion at the low end of its range: Since the midrange driver (or midrange-woofer) typically has restricted dispersion at the top of its range, where it hands off to the tweeter, reducing a tweeter's dispersion in that region can smooth the transition between the two drive-units' outputs. A waveguide can also, but not always, enhance a tweeter's dispersion at the top end of its range. The AF-61's concentric tweeter is protected by a web-like screen, and is crossed over to the aluminum-coned midrange at 2kHz.

That 5.25" midrange drive-unit has a 2" voice coil, which leaves plenty of room inside it for the wide-surround, 1" soft-dome tweeter. To isolate it from the woofers, this concentric driver is mounted at the front of its own separate, sealed chamber with anti-vibration mountings.

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While it might appear from the outside that the three-way AF-61 has three 8" woofers, it doesn't. What you see are three passive radiators. Each of these is partnered to its own 6.5" woofer, which operates invisibly, in an internal subenclosure. Together with two ports, that driver radiates into a second, smaller subenclosure that contains the passive radiator. The woofer and its ports never face the outside of the cabinet. Instead, their energy simply activates the 8" passive radiator, the "driver" you see. In other words: Each of the three visible woofers in the AF-61 is one of three separately enclosed woofer "systems," each comprising a 6.5" driver with two internal ports energizing an 8" passive radiator, the latter's diaphragm simply passing all of the bass to the outside.

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This arrangement acts as an acoustical filter, limiting the bass output to below 200Hz and eliminating some of the expensive crossover parts that would otherwise be needed to achieve the same low-pass crossover with a conventional network (a high-pass filter is still required on the midrange). It also eliminates audible port resonances. Elac calls this design Interport-Coupled Cavity loading.

This isn't a new idea, but rather a variation of what was called bandpass loading when it was first used, decades ago. It never caught on big, likely because it's somewhat complex and expensive. Regardless of possible savings on crossover parts, a passive radiator together with a more complex cabinet will still cost more than a cardboard or plastic port. But the Wayback Machine tickling the dark recesses of my brain says that KEF did use it in some of its designs, which may be where Elac's Andrew Jones first worked with or became aware of it.

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The cabinet structure required for this complex arrangement, with six separate internal chambers, not counting the small chamber for each midrange, makes for an extremely rigid enclosure, as rapping a knuckle on it painfully revealed. A heavy metal base plate, with outrigger corners and adjustable spikes, is also included. In addition, the AF-61s come with magnetically attached metal grilles. I used neither grilles nor spikes. The latter weren't sharp enough to penetrate the carpets that covered my hardwood floors, and if they had been I wouldn't put those floors at risk. I used a single run of speaker cable to each speaker, though biwiring or biamping are possible using each speaker's two pairs of high-quality binding posts. The available finishes are high-gloss black or white, or rosewood veneer (which looks more like dark walnut).

Setup
My listening area measures 21' long by 16' wide, with an oddly sloped ceiling at an estimated average height of 9'. This space is part of an open floor plan, with one of its 21' sides almost entirely open to a kitchen/breakfast area, which in turn opens into a dining room. The acoustic space is therefore far larger than the actual 21' by 16' listening area, which also accommodates the home-theater system used for my work for our sister publication Sound & Vision. That system includes two projection screens, but they're fully retracted when the main attraction is listening to music.

The room is relatively live, but apart from the kitchen, most of the floor area is covered with large, thick rugs. Shelves filled with books, CDs, and videos are on the back wall, several feet behind the listening seats.

1118elac.2.jpgI drove the Elacs with two channels (except where noted) of a Marantz AV8802A surround-sound processor, connected to two channels of a Proceed AMP5 five-channel power amplifier. In stereo operation, each of the Proceed's channels is driven by a completely separate power supply and transformer, not just separate secondaries from the same transformer—as used here, it operates as two monoblocks built on one chassis. Proceed, now long gone from the market, was the home-theater branch of Mark Levinson, and 20 years ago, when new, the AMP5 sold for $5000 ($1000/channel), or about $7700/$1500 today, and was specified as producing 125Wpc into 8 ohms or 250Wpc into 4 ohms, all channels driven. Roughly the size of a high-end preamp, the AMP5 is small for a five-channel class-AB power amp but weighs over 100 lb. The source was a Marantz UD7007 universal BD player, connected to the Marantz pre-pro with a coaxial digital cable.

Except as noted, all recordings used were on CD.

Listening
The 52"-tall Adante AF-61s are moderately imposing in a domestic setting. I set them up about 9' apart and 11' from the main listening position, which put their front baffles about 4' out from the front wall. The center of the AF-61's concentric tweeter-midrange is 46" above the floor, considerably higher than the typical seated ear height of 36–37". While my current listening ear height is a bit higher than that, it isn't close to 46". To compensate, I tilted the speakers forward slightly, and toed them in toward the listening seat. According to Andrew Jones, sitting slightly off the center axis on a concentric driver produces the lowest coloration, but I heard no clearly identifiable colorations in my setup.

While the initial listening tests were good, there was a distinct lack of impact below about 45Hz, obvious on material I know to have substantially extended bass. This wasn't entirely surprising, as it's also been true of some other speakers I've tested in this very large room. But my Monitor Audio Silver 10s have no problem producing convincing bass from the same positions, nor does an ancient pair of Energy Veritas v2.8s, the latter roughly the size of the Adantes.

When I performed a close-miked measurement of the AF-61s (fig.1) using an OmniMic measurement system from Parts Express (not nearly as sophisticated as the tools John Atkinson uses for Stereophile's speaker measurements, but excellent for basic measurements and setup), the response rolled off rapidly below 50Hz at about 18dB/octave (third-order). I measured all three of the front-mounted passive radiators, and they were essentially the same. Since bass frequencies are radiated from nowhere else on the AF-61, such as a port, these measurements indicates the bass capability of the speaker itself, with no help from so-called room gain. The single driver in Elac's Adante AS-61 minimonitor measured about the same when I reviewed that speaker for Sound & Vision, though the AF-61's three bass drivers' ability to minimize the well-known upper-bass floor-bounce dip (aka the Allison Effect), should offer benefits in overall bass balance and power handling.

1118elac.ElacMain-fig1.jpg

Fig.1 Elac Adante AF-61, nearfield response of passive radiators (5dB/vertical div.).

When a speaker is designed, certain assumptions must be made concerning the room in which it's likely to be used, particularly the room's size. All rooms affect the bass, including boosting the lowest frequencies—the room gain. The bigger the room, the lower the room gain, which is why a speaker used outdoors typically has anemic low bass. Designers who assume little room gain extend the bass as far as the design's size and budget allow. If a smaller room with a lot of room gain is assumed, the designer will keep the extension in check. I don't know what assumptions Andrew Jones made in designing the AF-61, but given the likely international appeal of the speakers, I suspect a room as big as mine, with little room gain, wasn't high on the checklist.

COMPANY INFO
Elac Americas
11145 Knott Avenue, Suites E & F
Cypress, CA 90630
(888) 541-0996
ARTICLE CONTENTS

COMMENTS
Bogolu Haranath's picture

May be TJN or JA or HR could review the new Elac Navis self-powered loud speakers?:-) .........

Moshe Ufnik's picture

"The company's current flagship line, Adante ..."

You haven't been doing your homework.
What about Elac's FS409 or the much higher-priced 500 series?
And did you forget their actual flagships - the Concerto and its little sibling Concerto M?

prerich45's picture

I believe Mr Norton was referring to Elac's new direction, as the 500/400 series and the Concerto lines were not designed by Andrew Jones. I've always wondered, as Andrew puts his stamp on the company, would he gradually design speakers to take the place of their old flagship lines?

Bogolu Haranath's picture

The Elac Flag-ship Concentro speakers (almost) look like KEF Blade loudspeakers .......... May be JA could review those Elac Concentro speakers? :-) .................

audio1321's picture

Hello, great article! May I suggest when using the OmniMic System to perform the bass measurements by placing the OmniMic on the floor and splicing the results with the high frequency measurements. This is very accurate considering access to a Anechoic Chamber is not feasible. This is because the reader will not be listening to the system in your space, we don't care to see the room's reverberation in the low end. Thanks :)

Ortofan's picture

... KEF R11 speakers - also priced at $5K/pr.
Or, for just $3,600/pr., one can now get the discontinued R900.

Bogolu Haranath's picture

If someone is gonna use Elac sub-woofer(s) anyway, they may be better off buying the Adante AS-61 bookshelf speakers and save some money ............ AS-61 are priced at $2000 - $2500/pair ......... AS-61 was favorably reviewed by TJN for Sound & Vision :-) ..........

jazzman1040's picture

Seeing that the Adante's have been out for the better part of a year, I wouldn't hold my breath waiting for a review of the new active ELAC's. How a so-called leading audio magazine can afford to be a year late when reviewing a highly anticipated product is beyond me. Btw, Stereophile, you should ditch CAPTCH immediately. It's a ridiculous verification system that took me about 50 clicks to verify I'm not a "robot".

Bogolu Haranath's picture

I got through .......... and I'm a robot ....... Hasta la vista, baby :-) ............

"I Robot" ................ The Alan Parsons Project :-) .............

John Atkinson's picture
jazzman1040 wrote:
How a so-called leading audio magazine can afford to be a year late when reviewing a highly anticipated product is beyond me.

We depend on companies being willing to loan us review samples, and it is getting increasingly difficult to to get samples from some companies. Although I doubt that this was the case with Elac, I suspect that this is often due to the fact that our reviews always include measurements. Companies appear to want a slew of positive non-measurement reviews elsewhere before they will send us samples for review.

John Atkinson

Editor, Stereophile

Bogolu Haranath's picture

Thank you JA for the measurements .......... JA is doing great service to the audiophile community by doing the measurements ........... Defend ton territoire (Stand your ground) :-) ..............

jazzman1040's picture

John, appreciate the thoughtful reply. Sounds like a tough predicament. A suggestion, for products like these that have more of an audience than some of the higher end stuff you review that is bought by scant few folks, maybe you could do a series where you visit the actual buyer's home and conduct the review and measurements with them, bypassing the company altogether. Now that would be innovation and certainly be more authentic than getting a pair from the company!

Mrsnikoph78's picture

In that case, please let the manufacturers know that if they restrict my access to quality information about their products I'm much, much less likely to ever purchase one. I depend on getting a full view of such luxury products to save hassle and shipping costs prior to purchase. Given how impossible it is to demo every great product that gets released, one is forced to shop wherever they can go to actually hear something. That eliminates 99% of the products I discover only on the Internet for a guy like me.

BTW measurements have a relationship to the sound quality of a product but they don't totally define it (they can't, because not everything is or can be measured let alone interpreted). Why fear a glowing review coupled to measurements that might not be "perfect"? Kinda ridiculous.

Bogolu Haranath's picture

"I Won't Back Down" ............. Tom Petty :-) ............

Juhazi's picture

TN wrote "Since bass frequencies are radiated from nowhere else on the AF-61, such as a port, these measurements indicates the bass capability of the speaker itself, with no help from so-called room gain."

This is still bad - there will be very little help from room gain when output drops that fast. Room help is most beneficial for closed box woofers that eg. Magico uses in floorstanders.

I don't understand at all why they use 6th order bandpass with a floorstander. Cost of copper is not that high...

(Message EDITED because of a misconception that JA noticed)

John Atkinson's picture
Juhazi wrote:
TN wrote "Since bass frequencies are radiated from nowhere else on the AF-61, such as a port, these measurements indicates the bass capability of the speaker itself, with no help from so-called room gain."

This is wrong - there will always be room gain indoors...

Not with a nearfield measurement, which is what Tom Norton was discussing.

John Atkinson
Editor, Stereophile

Juhazi's picture

Oops you're right! I was reading too fast.

I EDITED ORIGINAL POST

motberg's picture

The measured response seems a perfect match for my small dedicated room.. but I was wondering about the effect of using these more near/mid-field, like around 2 meters or so.

I currently have monitors but I think the feeling of overall image size may be better with floor-standers.

Bogolu Haranath's picture

If you already have monitors, and if you are happy with their midrange and treble sound, it may be a good idea to spend the money on powered subwoofer(s) ......... Separate subwoofer(s) allow the flexibility of room placement .......... There are several powered subwoofers available today, which are not very expensive and come with built-in crossovers and output levels .......... Chances are the same company which makes your monitors, also makes matching subwoofers :-) ............

Christian Thomas's picture

Bandpass loading is a superb idea, and this is a particularly interesting embodiment of it. Its advantage over direct radiators is that the acoustic low pass filter created - at 200Hz here - removes a significant proportion of the distortion components generated in the voice coil and magnet assembly. Down at the bass end is where they really start to get going and in some speakers you will see some truly horrific figures. These can't be filtered out by the crossover because they happen after it. If distortion is generated in the cores of the inductors, this too will be filtered. There can also be a small pickup in efficiency, which means that the speakers need a little less excursion, and so again improves distortion.

In this example the ports also vent into the bandpass chamber - which is a totally brilliant idea - so any port noise generated is also subject to this filter and, since that happens significantly above 200Hz, it will get attenuated almost entirely. This also applies to unwanted signal from the rear enclosure. There really is almost no downside to using a bandpass enclosure except that it can be difficult to get it to work above about 250Hz, which can limit your choice of crossover frequency.

Yes, there is a delay in the system, but we know essentially what it is. It's a phase shift of somewhere around 90 degrees at 200Hz (in this instance) and it makes up part of the crossover. It is essentially what you would have got by doing it electrically. What is even prettier is that there is a similar complementary mechanical high pass filter in the loading of the midrange unit, so you can have both the mechanical and electrical parts of each unit's filter be symmetrical. All in all it's a tremendous advance in helping get rid of distortion.

hb72's picture

Thanks for very interesting and detailed explanation of the system. Is 90deg phase angle really the overall phase angle of passive membrane excursion vs voltage input?

Christian Thomas's picture

The 90 degrees is an educated guess at what the target might be for the acoustic/mechanical part of the overall filter. It's exactly the phase shift one gets at the -3dB frequency with a 2nd Order Butterworth. That phase shift varies from zero at 0Hz to 180 degrees at infinity - in a smooth, reversed, s-shape. If you choose a soggier filter shape like a Bessel, then you will get a little less phase shift.

It's probably a pretty good guess, given the measurements above which show near perfect 24dB/octave rolloffs. So from that I would guess that the target is a 4th Order Linkwitz-Riley on both sides, and this is borne out by the fact that they cross over at 1/2 output, or 6dB down. A 4th Order Linkwitz-Riley is made up of two cascaded 2nd Order Butterworths so I would expect both the mechanical and electrical parts (of both drivers) to each have a Q of 0.707, which is the definition of a Butterworth. What is important about this alignment is that the phase responses of bass and mid overlay each other, so the delay at every frequency is exactly the same in both units.

As a caveat it is possible that either practical considerations, or a desire for greater efficiency in the drivers (which keeps them cooler), could mean that the acoustic Qs are higher and that this is compensated for in the electrical part, resulting in very nearly identical responses. Still, 90 degrees is a pretty good estimate, if possibly a near approximation.

Bogolu Haranath's picture

Andrew Jones (Elac) is one of the very talented designers around .......... He is very well known for designs with great sound for not a lot of money ........... His various designs have been praised for their great sound over many years by numerous audio magazines/websites including Stereophile .......... When he comes up with a new design, it is worth paying attention .............

lozsgo's picture

How do these compare to similarly priced GoldenEar Triton Towers?

John Atkinson's picture
lozsgo wrote:
How do these compare to similarly priced GoldenEar Triton Towers?

Both are excellent speakers. The GoldenEars will offer more bass, the Elacs a more refined midrange and treble.

John Atkinson
Editor, Stereophile

Bogolu Haranath's picture

There is a good chance the Elac Navis floor-standing powered speakers will match the GoldenEar Triton Reference in the bass department (almost) ......Triton reference probably will go lower in bass .............. We are waiting for a review in Stereophile :-) ..........

Elac Navis powered speakers are priced at $2,000/pair for bookshelf, and $4,000/pair for floor-standers ....... and they don't need any external power amps and speaker wires ............. Interested? :-) ..............

Bogolu Haranath's picture

Who is better? .......... KEF or Elac? ............. JA could be the judge :-) .............

Relayer's picture

I can't help but think the loss of low frequency extension could be solved by getting rid of the 6.5' drivers and just using 3 8' divers for the bass. It would simplify box design and probably lose weight to boot. Footprint, of course, remains the same.

Bogolu Haranath's picture

Looks like the AF-61 has somewhat 'screwed up' over-engineering in the bass department :-) ...........

Another good example why measurements are important ............. Thank you JA and TJN ........
Many other audio magazines/websites don't do these kind of measurements ........

The new Elac Navis powered speakers appear to be the very common and very popular bass-reflex design ............

Bogolu Haranath's picture

Google search and Wikipedia have info about band pass filter, passive radiators, bass-reflex (ported), sealed box (acoustic suspension) and transmission line designs :-) ...........

Also, look for 'loudspeaker enclosures' in Wikipedia :-) .............

hb72's picture

Looking at the step response I see a considerably longer delay until the passive membrane produces the peak (2.5ms ca after tweeter), a delay that appears consistent with the high order (6th) of the bass unit to fade out on frequency extremes. Note other speakers do 1ms or less (2-ways are usually particularly good, but also the tidal audio akira 3-way + passive membranes!).
The AF-61 has actually never been reported of lagging behind in bass (on the contrary – to my surprise!); still it seems a safe assumption that a driver driving a passive membrane via reflex system might need some semi-cycles to excite the passive membrane to full amplitude (and also to stop it). And I understand that the ear & brain parts are not so sensitive to phase shifts (think of a piano: the perceived sound of a chord involving many keys is not dependent on the exact phases the piano keys are played).
But then I wonder, whether speakers which are coincidental or near-coincidental down to bass (e.g. active digitals ones with FIR) are perceived notably different also e.g. w.r.t. reproduction of bass drums and possibly so for their ability to better convey PRAT etc. than e.g. the AF-61 does. Or are such differences in step response not really audible? Or audible more w.r.t 3d stage rather than PRAT & snap.

@ John Atkinson: any thoughts?

Many thanks in advance

rom661's picture

This feels like a blast from the past. I still own an Amp 5 and was a dealer in the day. It's... good. Surround processor, old demo disks. I don't like to evaluate speakers for two channel setups with surround processors but maybe that's just me. I've never heard a processor as good as a quality two channel preamp. My point for writing though, is simply how much I felt like I'd slipped back into the 90's while reading it. Oh, and the comparison with KEF's, no doubt the 104/2's. Wow.

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