Wilson Audio Specialties Chronosonic XVX loudspeaker Measurements

Sidebar 3: Measurements

With the large, heavy loudspeakers that Michael Fremer tends to review, I drive to his place with my test equipment. We maneuver one speaker onto a dolly and wheel it into his driveway for the measurements. However, with the 685lb Wilson Chronosonic XVX, this wasn't possible: I had to perform the measurements with the loudspeakers set up in Michael's room. The presence of early reflections from the room's boundaries meant that it wasn't possible to perform my usual gated, farfield frequency response measurements. Other than impedance and sensitivity, the only meaningful measurement I could make was the spatially averaged frequency response.

Wilson specifies the Chronosonic XVX's sensitivity as a high 92dB/W/m. My estimate was numerically the same using Stereophile's usual units: dB per 2.83V—not per watt—measured at 1m; the units are numerically equivalent only for an 8 ohm load. Wilson's specifications describe the loudspeaker's impedance as a nominal 4 ohms with a minimum value of 1.6 ohms at 326Hz, so the sensitivity measured in watts would be expected to be lower than specified.

Fig.1 shows the Wilson's impedance magnitude (solid trace) and electrical phase angle (dotted trace) measured with Dayton Audio's DATS V2 system. The magnitude remains between 2 and 4 ohms for almost the entire audioband, with a minimum value of 1.5 ohms between 310Hz and 340Hz—roughly consistent with Wilson's specifications. Using an Excel spreadsheet to calculate the EPDR (footnote 1), the resistive load that gives rise to the same peak dissipation in an amplifier's output devices as the loud speaker, revealed that the XVX is a very demanding load, with EPDR less than 1.1 ohms between 52Hz and 66Hz and between 197Hz and 287Hz, with minimum values of 0.91 ohms at 450Hz and 0.94 ohms at 3250Hz. The Chronosonic XVX should be used with amplifiers like MF's darTZeel monoblocks that don't have problems driving loads of 2 ohms and lower.

421WXVXfig1

Fig.1 Wilson Chronosonic XVX, electrical impedance (solid) and phase (dashed) (2 ohms/vertical div.).

Fig.2 shows the Wilson Chronosonic XVXs' spatially averaged in-room response. Using FuzzMeasure 3.0 (now owned by Røde Microphones), a Metric Halo MIO2882 audio interface operating at 96kHz, and an Earthworks QTC-40 microphone, I averaged 20 1/6-octave–smoothed spectra, individually taken for the left and right speakers, in a rectangular grid 36" wide by 18" high and centered on the positions of the listener's ears. This tends to average out the peaks and dips below 400Hz that are due to the room's resonant modes.

421WXVXfig2

Fig.2 Wilson Chronosonic XVX, spatially averaged, 1/6-octave response in MF's listening room (10dB/vertical div.).

The saddle centered on 21Hz in the impedance magnitude trace coincides with the tuning frequency of the Wilson speaker's port, which in turn suggests that the XVX is indeed a true full-range loudspeaker. Even though MF had to place the Wilsons close to the corners of his room, which exaggerates the speakers' midbass output, fig.2 indicates that the XVXes' in-room output extends below 20Hz. The dip between 130Hz and 230Hz will be due to room effects that have not been eliminated by the spatial averaging. The Wilson's higher-frequency output is generally smooth, with a slight downward slope that will be due to the increased absorption of the room's furnishings at high frequencies and the narrowing of the tweeter's dispersion in the top audio octave. Incidentally, looking at the outputs of the left and right speakers at the position of MF's head indicated that the outputs of the two samples in the frequency region where room effects were negligible were very well-matched, to within 0.5dB.

Fig.3 compares the Chronosonic XVX's spatially averaged response (red trace) with that of MF's long-term reference Wilson Alexx (blue trace) and the Sonus Faber Aida that he reviewed in October 2018. (Note the expanded vertical scale in this graph compared with fig.2, to make the differences easier to see.)

421WXVXfig3

Fig.3 Wilson Chronosonic XVX, spatially averaged, 1/6-octave response in MF's listening room (red), of the Wilson Alexx (blue), and of the Sonus Faber Aida (green). Note expanded scale compared with fig.2.

With the similar corner placement, all three loudspeakers produce high levels of midbass, though the Sonus Faber does so to a greater extent than the two Wilson models. The XVX has less of a dip in the lower midrange than the other two speakers, which I suspect is due to the wide vertical spacing of its two lower-midrange units. Both Wilson speakers output more energy between 1.5kHz and 8kHz than the Sonus Faber. The Chronosonic XVX's treble is more even than that of the Alexx.

In my own auditioning of the Wilson Chronosonic XVXes in MF's room, the balance was indeed as shown by the spatially averaged graph. The low frequencies were powerful and extended, though without any "boom." The clarity and smoothness of the treble were impressive, with a tremendous ease to the sound. The presentation of the soundstage on my own recordings was the best I have experienced. After I returned home, I listened to the same recordings on the Falcon "Gold Badge" LS3/5a's that I write about elsewhere in this issue. Even though the Falcons correctly positioned the acoustic objects in the soundstage, the presentation was so much smaller-scale than it had been on the big Wilsons that I had to chuckle.—John Atkinson


Footnote 1: EPDR stands for Equivalent Peak Dissipation Resistance. See "Audio Power Amplifiers for Loudspeaker Loads," JAES, Vol.42 No.9, September 1994, and stereophile.com/reference/707heavy/index.html.
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COMMENTS
Old Audiophile's picture

Michael, another good review and great piece of writing! Thank you! No way I can buy these toys but interesting reading, nonetheless.

In the same vein of "I've been married almost 33 years, and I have always found that things go well for me when I listen to my wife.", if you haven't already, I recommend you watch a few reruns of an old BBC production called "Rumpole of the Bailey", starring Leo McKern. Great actor who showed his talent for the witty as Clang, the native chief or shaman in the 1965 Beatles movie, "Help!". I'm confident you'll enjoy it and appreciate the humor.

w1000i's picture

This speaker need something double down to 1 ohm easily like Luxman amplifier

georgehifi's picture

I can think of far better amps to ignore those types of loads, than
"MF's darTZeel's"

EG: D'Agostino/Gryphon Antillion etc.

Cheers George

a.wayne's picture

Both amplifiers are not current kings IMO , the Luxman for sure would not be a step forward for MF ..

Regards

Ortofan's picture

... be a step forward for MF.

https://www.stereophile.com/content/luxman-b-1000f-monoblock-power-amplifier

a.wayne's picture

Nice had forgotten about those , have heard the other models and they were not my cup of tea , found them kinda on the soft smooth side ..

Regards

Ortofan's picture

"Even though the Falcons correctly positioned the acoustic objects in the soundstage, the presentation was so much smaller-scale than it had been on the big Wilsons that I had to chuckle."

PS Audio's Paul McGowan suggests that large-sized speakers are not necessary to achieve a large-scale soundstage, but it does require full frequency range reproduction, as might be realized by using relatively smaller speakers along with a subwoofer.

Has JA1 tried using the Falcon LS3/5a speakers with a subwoofer?

https://www.youtube.com/watch?v=XhWj-puaxx8

a.wayne's picture

Adding Subs or more bass will increase dynamic impact in the bass , for balance you do need more dynamic output from your mid/Twt so starting small there will see no real improvement in dynamic output and balance, just more bass and constant fiddling with subwoofer gain as you become aware of the lack of balance from Recording to recording ..

Regards

David Harper's picture

any wife who doesn't point out how ugly, expensive and ridiculous these speakers are is definitely a keeper.

Michael Fremer's picture

Yes they are expensive, but no they are not ridiculous nor are they ugly. Next time you're in NJ assuming you're not an anti-vaxxer, come over and listen. Then report back. Even before the review ran, once the XVXes showed up in associated equipment I got emails from readers who own XVXes telling me I need to buy them and from people who don't own them who've heard them telling me to buy them. I've never gotten such a reaction but I fully understand. The performance is ridiculous. Ridiculously credible. I almost typed "incredible" but didn't want to give you an opening.

Anton's picture

"A second Mk5 tweeter is mounted atop the upper-midrange enclosure."

On their site, Wilson calls it a 'rear firing tweeter.'

How do they time align that baby?

There are several speakers with aspirations at the highest of high end, Wilson, MBL, others, who seem to feel their products need an 'ambience tweeter.'

Like in Portlandia, "Want your speakers to sound better? But a bird on them!"

Have any of the manufacturers even discussed the non-time aligned ambience drivers?

Most importantly, where is the "Add a rear firing tweeter" after market product niche?

I use the Aperion ribbon behind my main speakers. So, maybe it already exists but doesn't get mentioned.

This topic might be coming up more now that so many high enders are doing it!

The Magic M9 does not, but the Wilsons, including the Chronosonic Master does! Their brochure: "The rear-firing module is optimized for ceiling heights normally found in domestic environments and increases spatial retrieval and overall resolution."

Not time aligned, yet "adding spatial retrieval and adding resoultion?"

MBL's Radialstrahler mbl 101 X-treme has a tweeter stuck on top, too.

JA1, MF, or JA2, are you noticing a trend?

PAR's picture

Rear and/or upward firing tweeters are no new trend but have been around for decades. The first I remember ( and it probably wasn't the very first) was the Linn Isobarik with additional midrange and tweeter firing at the ceiling (circa. 1975). The late Albert von Schweikert applied for a patent on his rear firing tweeter ambience recovery system in the early 1980s. There have been many speakers using similar concepts since.

bpeugh11's picture

Anton, what is a non time aligned ambience driver? The upward/rear firing driver in the XVX is time aligned to the drivers nearest them. What is also important is the adjustable output such that they can be set for the proximity of the ceiling. That setting determines the efficacy of the rear firing drivers.

Anton's picture

I find it intriguing that such high end manufacturers do this.

I like it and play with it myself at home.

It's a little touch of Bose in the night!

volvic's picture

I have no doubt they are amazing in any large listening area, I've heard the other Wilsons and they've always amazed me. Love the part where Mr. Fremer's wife thought he should get them. Wondering if my wife will be as forgiving if I purchase a 1200G?

JRT's picture

Thank you for the effort that you are putting into these measurements and the associated comments.

You have mentioned EPDR here and in some earlier articles, but are not including a curve showing EPDR in your measurements pages. It would be better if you would include an EPDR curve with the curves for electrical impedance and associated phase, all three curves with respect to frequency on the same graphic.

This suggestion is intended for improvements, and is not a negative criticism of the useful and interesting measurements and associated comments that you are already providing.

dc_bruce's picture

One can't help but be impressed by MF's and JA's comments. They should forestall any carping about "audio jewelry" or that these are only for those with "silly money."

Obviously, this speaker is like the proverbial yacht: if you have to ask the price, you can't afford it. I'm wondering whether, in a house with a typical suspended wood floor, some reinforcement might be necessary to support this much weight. I gather MF's listening room is in his basement, I assume with a poured concrete floor which eliminates this concern. (although I would not volunteer to be part of the crew that has to remove them).

The degree of precision in the available adjustment of the midranges and tweeters suggests that proper setup of these speakers will take quite some time to get "perfect" -- that it's not just a matter of positioning.

Although these are reasonably beyond my financial reach (I do have to ask the price), I appreciate this review, which gives us a glimpse of what is possible with nearly unlimited resources. Well done, all!

MikeP's picture

Your wife will love the new Ayon Audio Black Crane speakers...

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