Elac Debut B6 loudspeaker Measurements

Sidebar 3: Measurements

I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone to measure the Elac Debut B6's frequency response in the farfield; for the nearfield frequency response, I used an Earthworks QTC-40, which has a ¼" capsule and thus doesn't present a significant obstacle to the sound.

My estimate of the Elac B6's voltage sensitivity was 85dB/2.83V/m, which is 2dB below the specified 87dB/2.83V/m. I suspect that this difference is due to the B6's behavior in the top octaves (see later). I have plotted how the Elac's impedance varies with frequency on a more extended vertical scale than usual (fig.1), as the magnitude remains above my usual 20-ohm scale limit for the entire treble region. With a minimum value of 6 ohms at 190Hz and an electrical phase angle that is high only when the impedance magnitude is also high, this will be a very easy load for the partnering amplifier to drive. Herb Reichert commented that the B6 "seems to like tubes." Indeed it does, and the shape of the solid impedance trace in this graph does suggest that the speaker's treble will be a little higher in level when connected to a tube amplifier's 8 ohm taps (again, see later).

Fig.1 Elac Debut B6, electrical impedance (solid) and phase (dashed) (2 ohms/vertical div.).

A prominent discontinuity in the traces just below 200Hz suggests that the enclosure has a serious resonance at that frequency. While setting up the speaker on my turntable stand to measure it, I noted that the cabinet seemed very lively—investigating the panels' vibrational behavior with a plastic-tape accelerometer, I found a very high-level, high-Q resonant mode at 188Hz that was present on all surfaces but highest in level on the side panels (fig.2). As HR wrote of the sound through the B6es of a recording of male voice and double bass, "I heard that vibrating box—not a little, but a lot. . . . [The speakers] were vibrating like sex toys!" There are also some high-level resonant modes present in the midrange.

Fig.2 Elac Debut B6, cumulative spectral-decay plot calculated from output of accelerometer fastened to center of top panel (MLS driving voltage to speaker, 7.55V; measurement bandwidth, 2kHz).

The saddle centered on 48Hz in the impedance magnitude trace in fig.1 suggests that this is the tuning frequency of the flared port on the cabinet's rear panel. This is confirmed by the nearfield measurement of the woofer's response (fig.3, blue trace), which has a sharply defined notch at that frequency. (The port resonance holds the woofer stationary at its tuning frequency.) The port's own output (red trace) peaks between 35 and 70Hz, and its upper-frequency rollout is free from high-level resonant modes. However, there is a discontinuity in the port's rolloff, as well as a small glitch in the woofer's output, at the frequency of the strong panel resonance. The black trace in fig.3 is the complex sum of the woofer and port outputs; the broad peak in the upper bass is an artifact of the nearfield measurement technique, the B6's low frequencies extending cleanly down to the port tuning frequency, where the output is down by 6dB in textbook fashion.

Fig.3 Elac Debut B6, anechoic response on tweeter axis at 50", averaged across 30° horizontal window and corrected for microphone response, with nearfield responses of woofer (blue), port (red), and their complex sum (black), respectively plotted below 300Hz, 850Hz, and 300Hz.

Higher in frequency in fig.3, the Elac's farfield response, averaged across a 30° horizontal window centered on the tweeter axis, is extraordinarily flat from the upper bass through to the high treble. This graph was taken without the skeletal, plastic-framed grille. With the grille, the speaker's output in the presence region dropped by more than 2dB. I took the opportunity to measure both samples; fig.4 reveals that they match superbly well for such an inexpensive speaker. (This graph was taken in-room, hence the uneven response below 1kHz.)

Fig.4 Elac Debut B6, in-room frequency response on HF axis at 24", left sample (blue) and right (red) (1dB/vertical div.).

The top octave rolls off a little earlier than usual, and coupled with the fact that the B6's lateral dispersion narrows significantly above 7kHz (fig.5), the Elac might sound lacking in top-octave air in medium-to-large rooms or in rooms that are heavily furnished. Herb's listening room is both small and relatively undamped, which is probably why he was not concerned by the speaker's somewhat muted anechoic output in the high treble. In the vertical plane (fig.6), a sharply defined suckout in the crossover region develops more than 15° above and 10° below the tweeter axis.

Fig.5 Elac Debut B6, lateral response family at 50", normalized to response on tweeter axis, from back to front: differences in response 90–5° off axis, reference response, differences in response 5–90° off axis.

Fig.6 Elac Debut B6, vertical response family at 50", normalized to response on tweeter axis, from back to front: differences in response 45–5° above axis, reference response, differences in response 5–45° below axis.

Turning to the time domain, the Elac's step response on the tweeter axis (fig.7) indicates that both drive-units are connected in positive acoustic polarity. The cumulative spectral-decay plot on the same axis (fig.8) shows a commendably clean initial delay.

Fig.7 Elac Debut B6, step response on tweeter axis at 50" (5ms time window, 30kHz bandwidth).

Fig.8 Elac Debut B6, cumulative spectral-decay plot on tweeter axis at 50" (0.15ms risetime).

Other than that audibly significant enclosure resonance in the lower midrange, Elac's Debut B6 offers excellent measured performance, especially when you take into account its affordable price.—John Atkinson

COMPANY INFO
Elac Electroacoustic GmbH
US distributor: Elac Americas, LLC
11145 Knott Avenue, Suites E & F
Cypress, CA 90630
(714) 252-8843
ARTICLE CONTENTS

COMMENTS
crenca's picture

in my office. I have them driven with an Emotiva a-100 amp (50w class AB) @ $149 and I am feeding them with 16/44 and higher content from computer via a iFI iDSD DAC @ $199. This less than $700 rig is my "computer speaker" set up, though I have them spaced out nicely and listen critically/pleasure from a good location in the center of the room.

This rig sounds amazing. In fact, it sounds absurdly good for the price. These speakers (and this little amp and dac) should put the fear of God in most sub $5,000 systems of any configuration or brand. I want Andrew Jones' autograph...

harishcs's picture

I was very happy to see Herb addressing the extremely annoying "great speaker-for the price" and "it won't replace your audiophile speakers" comments. Apparently it requires guts to violate one of the main axioms of the reviewer's creed: cost = quality.

adrianIII's picture

Second this! One of my most hated phrases in audiophile reviews is "for the price." To me, it almost negates everything else said in the review. "For the price" is also an "out" for the reviewer.

David Harper's picture

I don't know which reviews are being referenced in this article, but the review I read in TAS raved about the ELAC's without reservation or qualification.
Sounds like harishcs nailed it; if it isn't overpriced, it can't be very good.

iris's picture

how well do you think these will play with TV and movies. i plan on making this my default all in one system

bdaddy60's picture

Indeed ! I bought a pair of B6's.....they are very very good and a value beyond description in an industry crowded with pretenders at price levels unjustified by anything to do with music reproduction. I laughed at least two little farts out as Herb named names...Kef LS50 and Falcon LS35A, dare I add the Harbeth PES3 and the little Proac's to the list of speakers that the B6's puts to shame at the cash register. Has Andrew Jones gone too far ? I don't care I matched the B6's with a solid well known over achieving integrated (solid state) amp and have been routinely inviting my audiophile friends over to watch them squirm...now we're having fun !!!

SridharPoli's picture

Just wondering how good these Elac B6's are compared to Pioneer floor standers FS52s?
You would be wondering why I am comparing Bookshelfs with FloorStanders? Well I like music to sound in its full spectrum nothing should limit the music coming through my NAD D3020, I dont care if i am listening to small or big speakers, i want everything in the recording including the dynamics, depth, warmness, richness, Timbre, musicality.... Yes, Pioneer FS52's has them all but it has its own limits. They are good for the price no questions about that but will Elac debut B6's or Debut floor standers that i need to target next? I want to go to next level now, please help me with your suggestions. I play music straight from my sony vaio through to NAD D3020.

adrianIII's picture

I wonder about this comparison too.

partain's picture

I am caught in a bind.
I bought the Debut6s and was blown away.
Before I had them two weeks , I decided my amp needed to match the quality of the speakers and got a NAD D7050 . ANOTHER revelation in sound !
My rig now exceeds all expectations.
I read about MQA and that TIDAL is trying it. I stream from TIDAL (hifi).
So , the problem is....is it the speakers , is it the amp ? The MQA ?
Is my hearing coming back ? ( I'm 67 )
It is a sweet problem to have.

bdaddy60's picture

I totally get what your saying I matched B6's with a NAD integrated and have been irritating my "audiophile" buddies with this rig...We're all in our 60's as well. What bothers me about this rig is of course the price. Consumer susceptible to marketing that I am I've spent more on speaker cables than these B6's retail for, in fact the 10ft. pairs of Kimber 4TC with Audio Quest banana's I use are more costly. Time to be content and enjoy music.

GustavoS's picture

Hello,

Very insightful review. I wonder if you would prefer Elac over Paradigm Studio 20 v5, especially for Rock and Roll? Also, are this Elac by itself "very good" for listening to rock and reggae music?

Many thanks!
Gustavo

SridharPoli's picture

Just wondering how good these Elac B6's are compared to Pioneer floor standers FS52s?
Just wondering how good these Elac B6's are compared to Pioneer floor standers FS52s?
You would be wondering why I am comparing Bookshelfs with FloorStanders? Well I like music to sound in its full spectrum nothing should limit the music coming through my NAD D3020, I dont care if i am listening to small or big speakers, i want everything in the recording including the dynamics, depth, warmness, richness, Timbre, musicality.... Yes, Pioneer FS52's has them all but it has its own limits. They are good for the price no questions about that but will Elac debut B6's or Debut floor standers that i need to target next? I want to go to next level now, please help me with your suggestions. I play music straight from my sony vaio through to NAD D3020.

syj's picture

In my humble opinions, after living with them for many months, I can assure that they are all very good speakers as reviewed by Stereophile and else where. Anyway, I think Elac debut B5 is as good as B6, if "NOT" better esp. in the mid range (however, you will need a really very very good amplifier to hear the difference which is minor). I think B5 mid-range has less coloration than the bigger brother, despite its a little less bass, less sensitive, and a little harder to drive.

And I am very certain that the Wharfedale is not as good as the Elac debut brothers. Wharfedale Diamond 10.1 is surely harder to drive than the Elac.
Because, I tested driving the Elac B5 and the 10.1 with Marantz MCR-610.
The B5 sounds very good, 10.1 seems a little constraint and was boring overall. I then switched to NAD D3020 (surely a better Amp than the MCR-610), the 10.1 sounds much better. However, there is no doubt that the B5 is also better via the D3020. I went on to check the impedance graph of Diamond 10.1
in Stereophile review, finding it has less than 5 Ohm, even less than 4 Ohm, in some frequency areas, hence giving the MCR-610 a hard time.

The Debut brothers and the Diamond 10.1 are better with the Amp too. I
listened to them with Exposure Amp and can confirm that they all sound
better than driven by NAD D3020. [My Exposure 2010 power amp and my
friend's Exposure Classic 23 & 28].

Conclusions:

1. Elac Debut B5 and B6 are quite equal in Sound Quality, depending upon
your room size and response. Both are better than Wharfedale Diamond 10.1.

2. MCR-6xx/5xx are very good indeed, esp. the Network Streaming player
and USB player (but both 610 and 611 have problem reading USB or read USB
very slowly) are so good. Their class-D amp is excellent with easy-to-
drive speakers. Elac B5/B6 seem to be a really good match in heaven with
Marantz MCR-6xx,5xx. BTW, I cannot find any difference between 610 and
611. They sounds to me just same. [But, during the break-in period, 611 seems
a little weaker overall, after that they are the same.] Their analog input(s)
are so-so (avoid it).

3. NAD D3020 Analog input is far better than its Digital inputs.
Plus its class-D amp is excellent although just 30Wpc (a little conservative). It is able to drive my father's old KEF 104.2 to some degree,
but within an hour or so it is very hot and the distortion is more
than acceptable. This is a really good "Portable" analog class-D Amplifier.

4. Elac B5/B6 sound better with D3020 (with MCR-61x being the front
end) than with MCR-61x. However, The very low total cost of ownership
(TCO) for MCR-61x/51x with Elac debut B5 will beat (as far as I know)
everything in Hi-Fi world. Just connect them with a pair of good
speaker-wires, you will be very very happy.

crabdog's picture

Would love to see a comparison with the Wharfedale Diamond 225.

Ixtayul's picture

I wold love to see a comparison between B & W CM5 or 2 and Elac B6

GLADYS ZYBYSKO's picture

Um, didn't all the reviewers go equally bats**t over his last "designed from the ground up" inexpensive line for Pioneer?

And didn't they all have tweeters that pooped out at 12k? Despite the "high quality" crossover?

And didn't they all sound schvach (weak) in their audio balance?

I know I sold mine after 6 months of constantly fiddling with placement ... to no avail.

adrianIII's picture

I'd venture to say that most human's EARS poop out at 12kHz... especially those reading Stereophile reviews!

GLADYS ZYBYSKO's picture

That may or may not be true, but a speaker that poops out at 12K sounds different (and less accurate) even to someone whose ears poop out at 12K. I don't have the time or inclination to prove this to you, but Google is your friend.

I have no idea why you posted a pointless dig at Stereophile readers .... in Stereophile .... but, there you are. Why you are thus here, I do not know ... nor do I especially care to.

markich17's picture

Hi, I have an amplifier Yamaha AX450 with 65W per channel. Are these spearkers a good match with my ampplifier? Thanks!

David Harper's picture

I have ELAC B6's ( connected to an analog rig) and Polk Rtia5 floorstanders(connected to a digital rig). I love the sound of both speakers. They sound different,but I couldn't say which sounds "better".I put better in quotations because I'm not always sure what that means when referencing audio gear. Obviously I'm not comparing sq when they're connected to completely different systems. But they both sound very good to me. With a good LP, like Eric Clapton "Unplugged" the ELAC's sound amazing. And with good digital material (my player is an OPPO UDP 203) the Polks may be one of the most underrated speakers in all of audio.

Darren1965's picture

I have a par of the elac's B6.5
Hooked up to my NAD C 375BEE 150 watts @ 8 ohms per channel
They sound great.
For the money you can't go wrong.
The NAD controls the speakers with an iron fist and will shack the walls of the house if you want to.
I am also using "TIDAL" HiFi & Master.
MY @ cents worth.

fugue137's picture

My Epos ES12s are broken (torn woofer gaskets on both sides), so I thought I'd give these a shot. I've had them for a couple of weeks now. Driving with Acurus LS11 and A80, various input sources (but suddenly, to my surprise, defaulting to the rather impressive Audioengine B1!). My 24" lead-filled stands and OFC cables are price-commensurate. I've tried them in a couple of rooms with a couple of placements, but not more than about 14" from the wall.

I mostly listen to classical music (and play a bit). I am one of those annoying people who somehow still hear the test tones that "you can't hear if you're older than 17".

I find that these speakers are sorely lacking in treble. They just sound veiled or muffled or something, with a good mid-range and more bass than I got from my ES12s, but little sense of breath or presence. They are pretty directional, and everything is better if I toe them way in and sit right at the sweet spot, but even then my criticism stands.

Help! Any advice? Do I simply need a better amp? Did I just choose the wrong speakers for my room / ears / musical tastes? In a smaller room, with a Yamaha RX-385, my complaints intensify. I'm not overly inclined to put $300 speakers on $700 stands and drive them with a $2000 amp, but I suppose if they're "amazing at any price" it might be reasonable to do so (although I'd rather put the money into a better cello).

I see that Elac has just released a new version, and they claim similar response curves but greater transparency and high-frequency extension. The price is basically the same. Seems almost a no-brainer to return these and replace with the B6.2, but I'm not sure it would help very much. Is something obviously wrong with my setup? Is it time to finally upgrade to Maggies?

Many thanks!
-Ben

flyboy217's picture

Curious, did you ever get it figured out? I find I have to use an equalizer to boost 5 KHz+. I'm genuinely surprised anyone likes them stock. But it might also be my cheap class D amp that's to blame.

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