Genelec G Three active loudspeaker Measurements

Sidebar 3: Measurements

I used DRA Labs' MLSSA system, a calibrated DPA 4006 microphone, and an Earthworks microphone preamplifier to measure the Genelec G Three's frequency response in the farfield. I used an Earthworks QTC-40 mike for the nearfield responses.

Genelec specifies the G Three's input impedance as 10k ohms. As this is an active loudspeaker, I calculated the input impedance by using spot frequency tones generated by my Audio Precision SYS2722 and examining how the nearfield sound pressure level dropped when I increased the source impedance to 600 ohms from 20 ohms (single-ended) and 40 ohms (balanced). The single-ended impedance was close to 3.6k ohms across the audioband; the balanced impedance, as expected, was twice that value. While the lowish unbalanced input impedance won't present drive difficulties with solid state sources, the bass might sound a touch lightweight with a tubed preamplifier.

With the unbalanced input fed white noise at a magnitude of 330mV, the B-weighted SPL at 1m was 85.7dB(B). Genelec specifies the maximum long-term SPL as 97dB at 1m. My sensitivity estimate implies that this would be achieved with an input signal of just below 1.2V. (The 10dB attenuator was switched off for this measurement.)

I investigated the enclosure's vibrational behavior with a plastic-tape accelerometer. It was extremely inert. The only resonant mode I found was on the sidewall, at 637Hz (fig.1), but this is vanishingly low in level, even at SPLs >90dB.

722GenG3fig1

Fig.1 Genelec G Three, cumulative spectral-decay plot calculated from output of accelerometer fastened to center of sidewall (MLS driving voltage to speaker, 760mV; measurement bandwidth, 2kHz).

The blue trace in fig.2 shows the nearfield woofer output, the red trace that of the port on the speaker's rear. The notch at 54Hz in the woofer's output indicates that this is the port's tuning frequency. Both the woofer and port outputs roll off below that frequency with close to an 18dB/octave slope rather than the usual 12dB/octave slope. This implies the presence of a series capacitor in the woofer feed to limit low-frequency excursion. A couple of midrange peaks can be seen in the port's output, but these are well down in level.

722GenG3fig2

Fig.2 Genelec G Three, anechoic response on HF axis at 50" (green) and the response 3" below that axis (black), both averaged across 30° horizontal window and corrected for microphone response, with the nearfield woofer (blue) and port (red) responses and their complex sum (black), respectively plotted below 300Hz, 950Hz, and 300Hz.

The rear-panel DIP switches were set to "Flat anechoic response" for these traces. Switching the bass to "–2dB," which is how the speakers had been set up by HR, reduced the levels of the woofer and port by 2dB. The "–4dB" setting reduced the levels by another 2dB, as did setting the bass to "–6dB." The "Tabletop" switch reduced the region between 150Hz and 300Hz by 2–4dB, while the "Low Bass –4dB" switch started the low-frequency rolloff slightly higher in frequency.

The black trace below 300Hz in fig.2 shows the complex sum of the woofer and port outputs, taking into account acoustic phase and the fact that the port is mounted on the G Three's rear panel. The low-frequency rolloff is steep, and the slight peak in the midbass region is due in part to the nearfield measurement technique, which assumes that the drive-units are mounted in a true infinite baffle, ie, one that extends to infinity in both planes. The farfield response on the tweeter axis, averaged across a 30° horizontal angle (fig.2, green trace), is extraordinarily even, though there is a slight lack of energy in the presence region. Repeating the averaged response 3" below the tweeter axis (black trace) gave a flatter output in this region, the Genelec's farfield output now meeting ±1.5dB limits from 300Hz to 20kHz. (The specified listening axis is midway between the two drivers.) The sharp ultrasonic spike at 27.6kHz is due to the metal-dome tweeter's fundamental dome resonance. These traces were taken with the "Treble –2dB" DIP switch set to Flat. Turning it on shelved down the G Three's output above 7kHz, reaching –2dB at 15kHz.

The G Three's horizontal dispersion, normalized to the response on the tweeter axis, which thus appears as a straight line, is shown in fig.3. The contour lines in this graph are evenly spaced, with the radiation pattern smoothly narrowing in the treble. This is textbook behavior. Fig.4 shows the speaker's dispersion in the vertical plane. A suckout appears at 3.2kHz, the frequency of the crossover between the tweeter and woofer, 5° above and more than 10° below the HF axis. This graph confirms that, as shown in fig.2, the flattest treble response is obtained 3" below this axis.

722GenG3fig3

Fig.3 Genelec G Three, lateral response family at 50", normalized to response on HF axis, from back to front: differences in response 90–5° off axis, reference response, differences in response 5–90° off axis.

722GenG3fig4

Fig.4 Genelec G Three, vertical response family at 50", normalized to response on HF axis, from back to front: differences in response 45–5° above axis, reference response, differences in response 5–45° below axis.

In the time domain, the G Three's step response (fig.5) indicates that the tweeter's output arrives first at the microphone and is connected in negative acoustic polarity. The woofer is connected in positive polarity. The decay of the tweeter's step blends smoothly with the start of the woofers' step, implying optimal crossover implementation. The G Three's cumulative spectral-decay plot on the tweeter axis (fig.6) is superbly clean, the only significant ridge of delayed energy occurring at the tweeter's dome-resonance frequency. (As always in my CSD graphs, ignore the ridge just below 16kHz, which is due to interference from the test computer's video circuitry.)

722GenG3fig5

Fig.5 Genelec G Three, step response on HF axis at 50" (5ms time window, 30kHz bandwidth).

722GenG3fig6

Fig.6 Genelec G Three, cumulative spectral-decay plot on HF axis at 50" (0.15ms risetime).

The Genelec G Three offers superb measured performance, and the versatility of its tone controls will allow that performance to be optimized for specific locations.—John Atkinson

COMPANY INFO
Genelec
US contact: Genelec Inc.
7 Tech Circle
Natick, MA 01760
(508) 652-0900
ARTICLE CONTENTS

COMMENTS
paulchiu's picture

Herb,

Did you use the Genelec G Three with a wireless streamer?

rerun712's picture

HR: I took a look at the setup for Falcons but didn't see a distance from listening position (guessing around 65" based on distance between the speakers). Perhaps I missed it. I am curious about your distance from the G3s and whether they'd work in a more conventional two channel set up?

Herb Reichert's picture

only 5-7 feet from the Falcons; but I imagine the G3s would work almost anywhere in most any room that is not too big. They can play loud and soft without distorting. And they are EQ adjustable.

h

paulchiu's picture

Herb,

Did you use the G3s with a wireless streamer?
I have pairs of Audioquest Sydney RCA sitting around waiting for action.

Paul
UWS

remlab's picture

..is that it proves, without a doubt, the accuracy of JA's measurements.

Glotz's picture

and HR. Too few understand without them.

It's funny it seems that their words only matter when measurements are provided... even more so when those measurements are positive.

Trust is rare thing these days. Sad.

Posh_Tippler's picture

Read about these Genelecs on Audio Science Review and bought them based on the detailed review and recommendation. Couldn't be happier. Prompted me to sell my Klipsches, Omegas, Sonus fabers, Vandersteens, Pass Labs, Haflers. BTW unlike certain opinion and suggestion based web magazines who shall remain nameless, ASR puts it all out there for the customer to take in and digest. No profit motive, no adverts, no smoke and mirrors and no hoary Golden Ears declaiming what "Audio Should Be!" in their biased, befuddled and financially conflicted opinions.

Truth is a rare things these days. Sad.

Glotz's picture

Smug retorts need substance. ASR puts out measurements and the only judgment Amir passes is measurement based only.

Moreover, what everyone buys on the ASR's site IS the best measuring gear and ONLY that. Another lie.

Other pretending that there's a recommendation based on sound in his writing is an obvious lie.

No one in this magazine tells 'what you should buy'. Only you and the posters on ASR believe that bs. You make up stuff just like the misinformation you consume. Stereophile even has a emphatic statement of this in their recommended components for the past 20 + years. (Where they don't tell you what you should buy ever..)

Hoary Golden Ears? You're nuts if you think TAS was ever serious about that. But you're looking only for the negative, much like all of the ASR cultists instead of being transparent and losing your anti-social attitude.

There is room for all of us. But don't bs anyone here.

And lastly before you use my language to feign smugness, look at your message and find the actual truth.

Glotz's picture

I never commented to the negative about Genelec speakers in any way, shape or form.

Stereophile provides both listening reviews and measurements. That too me is far more comprehensive and wrought over decades of experience. ASR can't claim either.

And semi-personally, I wonder why you would buy anything without a return policy. Sounds like you don't trust your ears, cause that's a lot of gear selling... and it also sounds like you sold a lot when a lot of other factors could have been addressed. Cables included.

What is out today is far more engineered with better technology, across the entire industry and globe. Decrying gear from decades ago is obvious and indicative of that time period.

Posh_Tippler's picture

Well done sir. A reply composed entirely of straw man fallacies! Voice of America should be proud of such talent!

Further thoughts:

Do people in advertising even go to college? If yes, do they dropout early due to "personal reasons"?

Foods for thought Herb, John, ...Fremer, et al: "Wherefore by their fruits ye shall know them. By Their actions shall you know them."
-St. Peter Aczel @ Matthew 7:20.

Yea Friends, let us not forget St. Peter Aczel @ Matthew 7:15:

"Beware of false prophets, which come to you in sheep's clothing, but inwardly they are ravening wolves."

Perhaps ye shall repent your ways and beg forgiveness of the multitude. Perhaps not.

Regardless, I wish ye all peace and humility in your journey to the stars!

-P_T

Glotz's picture

It smells quite foul. And you so valiantly almost-argue yourself out of the paper bag.

What happens when Amir kicks it or no longer wants to produce report after report correlating sound quality based on measurements? Are you hoping another other semi-retired guy who likes performing tests more than listening to music can find all of the time it takes to produce hundreds of 'reviews'? And gosh I really hope that person never creates a false narrative while producing those pictures and graphs (like ASR).

I could only wish. Instead, this magazine realizes the environment that every American must weather and succeed in (especially in the age of the internet).

We as consumers that actually buy stereo equipment must endure the woeful deluge of commercial assault and wade through the murky waters of marketing to find the truth in music.

Fortunately, we have trusted journalists that respect the livelihood of cottage-industry engineers and business owners that create the gear we buy. They tell the truth, but they respect the company and designer that has put their entire lives on the line to produce bespoke audio components.

They do this by focusing on the positive, active listening for musical enjoyment, rather than decrying a product based on speculative and theoretical suppositions.

It's the concept of listening and reporting with measurements versus implicating components based on a limited and inadequate measurement group and then arbitrarily spewing value on a small subset of objective findings.

A $12,000 preamp with worse measurements than my $3000 Benchmark HPA-4 will still sound better 9 times out of 10.

When parts quality goes up, the 'immeasurables' become more audible.

Glotz's picture

That you are the only 'sucker' in the room... (See P.T.'s laundry list of sold, used-components that he was never happy with.)

"Prompted me to sell my Klipsches, Omegas, Sonus fabers, Vandersteens, Pass Labs, Haflers."

Full Circle Burn.

Lol.

Posh_Tippler's picture

My butler tells me I may have hurt your feelings with my plain speaking.

To that I say "Toughen up buttercup!" Life isn't for the faint or weak hearted. Anyone sitting around with enough time on her hands to reply twice to singular postings clearly doesn't have enough to do Karen.

Get a dog. Join a bridge club. Tutor an underprivileged child. There's a whole bright shiny world out there.

But YOU have to take the first step.

Glotz's picture

M'kay.

Posh_Tippler's picture

Sorry, can't hear you anymore over the sound of my glorious Genelecs.

:)

tenorman's picture

Beautifully written and informative - thank you HR

Herb Reichert's picture

tenoman. I am honored that you read it and pleased you enjoyed it. I really enjoyed writing it. And those speakers are a revelation.

peace and fireflies,

herb

remlab's picture

.

Herb Reichert's picture

remlab,

Something tells me we've met or know each other. Is that possible?

peace and summer storms

herb

Hi-Reality's picture

Thank you Herb and John Atkinson for this brilliant analysis. It is hard to imagine the Audio Realism level delivered by diverse Genelec active speakers and their GML software can be matched or exceed by any loudspeaker / amp combination from traditional "HiFi/Audiophile" brands.

We are in fact considering to deploy Genelec 8320A 4 inch Powered Studio Monitor (SAM) and Genelec 7350A 8 inch Powered Studio Subwoofer with GLM software as reference in our "Hi-Reality Machine" prototype #5.

Regards, Babak
Founder, Hi-Reality Machine
Youtube channel: Hi-Reality Sensorium

Rethep's picture

Nice review.

But, the song 'Melena' is not on my album "Sera Una Noche"! Maybe you meant another one?

Very beautiful music of Cheng Gong Liang. The instrument played is a cither called ghuzeng in China. About the same cither in Korean, is called 'gayageum', and in Japanese: 'koto'.

More of this instrument: Liu Fang, who also plays pipa, and also in Korean music are many beautiful pieces, on gayageum.

"Sault" is very special, indeed.

Herb Reichert's picture

on a hard drive

h

patrickf.orlando@gmail.com's picture

Man, these are some ugly looking speakers.

Posh_Tippler's picture

Such outstanding performance as noted by both the reviewer and the technician and yet none dare call them "Reference Speakers" despite that fact that's how they are used by recording studios and their objective performance clearly dictates. Pray tell what must these highly engineered and competent speakers provide to be included in that hallowed list? Is it sweet kickbacks to the editor? Free trips for the reviewer and technician? Splashly full page ads in the print magoo?

Do tell...

DarkStar_64's picture

Those are the ugliest speakers I have ever had the misfortune of laying eyes on! They look like something from around 1984 to use with your Atari video games... Just sayin'. ;)

orfeo_monteverdi's picture

[please forgive my poor English]

Hello all, I am a new member here (Stereophile reader since a long time though).

Thanks Herb for your review. Always a pleasure to read you.

When I saw the anechoic response of the active G Three, measured by JA, I immediately recognized a similarity with the passive Harbeth M30.2 Anniversary's response (that you reviewed in Mar 2018, and rated as 'class A - restricted LF' speakers). I could not wait, I had to check at once, and I found back JA's measurements in a snap.

Indeed, except that the Genelec have a somewhat smoother low-mid/bass-emphasis, it seems (to me at least) that there is a similarity between the repective anechoic response of each speaker, especially taking the Genelec measured on HF axis (see green curve: had Genelec wished to mimic a BBC-dip around the 3 KHz region, they might not have acted otherwise; of course, I am not suggesting that mimicking a BBC-dip was Genelec's goal, nor that yet another debate about the BBC-dip should be triggered again).

Genelec G Three anechoic response. ACTIVE
Cf. Anechoic response on HF axis at 50" (green)
Stereophile Aug 2022

Harbeth M30.2 Anniversary - PASSIVE
Stereophile Mar 2018

Herb, did you have the opportunity to compare (even 'privately') the Genelec G Three with the Harbeth M30.2 Anniversary?
(you may no longer have the M30.2 under the hand).

I am aware that comparing a passive with an active speaker has limited pertinence, as an amplifier has to be used to do so in the case of the passive, which acts as an unpredictable variable (and, for sure, on other measurements than anechoic IRR, we all can note that the two speakers are dissimilar).

It is also possible that a large part of the difference between G Three's and M30.2's Anniversary lies in the presentation: more forward and "monitoring" for G Three, more "mid-hall" for the M30.2, both delivering musical rendition that would be considered as enjoyable by the same listener, each speaker giving him the feeling to sit on a different seat in the same concert hall. BUT, the differences may be much greater than that. Therefore my question.

CONTEXT

I own a pair of M30.2 Anniversary quickly bought for the hasty setup of a 2nd system in the countryside, during the lockdowns, in order to survive musically speaking. They are setup in a 40m² former stable, made of brick wall with a ceiling made of curvated little vaults; the room acoustics is astounding. I initially did not figured out "how much" I would survive thanks to those little marvels on classical music, the most demanding of all (I attend live acoustic, unamplified, performances nearly each week, in the best seats of the best concerts halls - it fine-tuned my ear-brain over the years; as I am still young, as I obsessively protected my ears while I went in clubs, I am still very demanding regarding treble, its naturalness, and its flawless integration with the medium; the latter being preferably to-die-for; as for bass: as soon as cello is more or less OK or vaguely credible, I am happy).

I do not intend to switch, or ditch the M30.2. I just wondered if we could achieve a similar result with the Genelec G Three as a commmon gift for a girlfriend's birthday (or for myself, in a 3rd system in an office/sleeping with wobbling wood floor and walls; tone controls could be welcome here).

PS: I struggled with the HTML tags by respect of all members' eyes; so I HOPE that the link to my hosted picture will pass...

Kind regards from Europe.

Orfeo

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