Vandersteen Model Seven Mk.II loudspeaker & M7-HPA monoblock power amplifier Vandersteen Seven Mk.II Measurements

Sidebar 3: Vandersteen Seven Mk.II Measurements

As the Mk.II Model Seven loudspeaker differs only in detail from the original Model Seven, I refer you to the measurements sidebar that accompanied Michael Fremer's review for the overall picture. I performed only a few measurements on the updated version. Fig.1 shows its electrical impedance and phase, taken with the two pairs of binding posts in parallel. This is generally similar to that of the Mk.1, and, like that speaker, drops to a low value at the top of the audioband, particularly with the rear tweeter turned on. The minimum magnitude is 2.55 ohms at 17kHz, but between 80Hz and 12kHz the impedance remains within more reasonable limits of from 4 to 7 ohms, with a generally low phase angle. The peak at 62Hz indicates the tuning frequency of the front-mounted 7" woofer.

Fig.1 Vandersteen Model Seven Mk.II, electrical impedance (solid) and phase (dashed) (2 ohms/vertical div.).

The red trace in fig.2 shows the spatially averaged response of the Model Seven Mk.IIs in my listening room. As usual, I generated this graph by averaging 20 1?6-octave–smoothed responses taken for each speaker individually in a vertical rectangular grid measuring 36" by 18" and centered on the positions of my ears in the listening chair. I used an Earthworks QTC-40 omni microphone and a Creative E-MU0404USB audio interface, in conjunction with SMUGSoftware's Fuzzmeasure 3.0 running on my MacBook Pro. The blue trace in this graph shows the spatially averaged response of the YGA Carmel Two speaker, which I reviewed in December 2015, taken under identical conditions. The two different speakers have broadly similar measured responses between the upper bass and the mid-treble, though the Vandersteens have less energy at the bottom of the midrange. The Model Seven's powered subwoofers extend their output to 20Hz, though even with the settings of the 11-band equalizer chosen by Richard Vandersteen when he set the speakers up in my room, the low bass is a little too high in level, the midbass a little too low.

Fig.2 Vandersteen Model Seven Mk.II, spatially averaged, 1/6-octave response in JA's listening room (red); and of YGA Carmel Two (blue).

The rear tweeters were turned off for this measurement; you can see that the Model Sevens have lower levels of mid-treble and top-octave energy than the Carmels, conforming more closely to the optimal upper-frequency rolloff in my room. (What you don't want to see in this kind of measurement is a flat treble response, which corresponds to a rising on-axis output in this region.)

Finally, like its predecessor, Vandersteen's Model Seven Mk.II offers a true time-coincident output, due to the stepped-back subbaffles for the upper-frequency drivers, the first-order crossover slopes, and the fact that all its drive-units are connected in positive acoustic polarity. Richard Vandersteen strongly believes that a loudspeaker should faithfully preserve the waveform produced by the power amplifier, including "all of the delicate time-domain relationships that comprise the recorded musical performance." Fig.3 shows the left-channel speaker's step response at the position of my ears in the listening room—although it is subsequently disturbed by room reflections, the initial arrival is an almost textbook right-triangle shape. Goal achieved.—John Atkinson

Fig.3 Vandersteen Model Seven Mk.II, step response on upper-midrange axis at JA's listening position (5ms time window, 48kHz bandwidth).
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COMMENTS
ctsooner's picture

What a great review of an amazing powered speaker system with what sounds like some first ever experiences, especially with some of your own recordings. I must admit though that after reading the conclusion I wondered why you withheld any recommendation for this system. I read your first paragraph and you spoke about getting more that you expected. After rereading your review, I get that same feeling you had with the original 2's. Can you highly recommend this system? Thanks I value your response.

John Atkinson's picture
ctsooner wrote:
After rereading your review, I get that same feeling you had with the original 2's. Can you highly recommend this system?

Yes Indeed. It broke my heart when the shipping company picked it up last week to be returned to Vandersteen. And a full-range version of the Vandersteen M7-HPA monoblock would be a wondrous amplifier indeed!

But there is a certain relief in being back in the land of audio components that I can actually afford!

John Atkinson
Editor, Stereophile

ctsooner's picture

John, thanks so much for responding and sharing your thoughts. The best thing about Vandersteen is that they DO have affordable for nearly anyone as they have a trickle down, signature sound. I converted to them a few years ago as a lower cost of admission and am very happy with them.

Sea Otter's picture

Good to see a designer sticking with his inordinate design criteria, and taking it to it's logical extremes. I believe he has developed what may be the best cone construction in the industry with his carbon/balsa drivers.

While his speakers aren't quite my cup of tea, I certainly respect him as one of the most diligent and talented designers in the industry.

Alpinist's picture

I recently purchased the Vandersteen Model Seven Mk II Speakers and Vandersteen M7-HPA Mono Amps from John Rutan at Audio Connection. John positioned the speakers in my family room using laser sighting and tuned the speakers' powered subwoofers with their 11-band equalization to give an even response in my room across their frequency range.

The ability to tune the bass on these speakers has made them integrate into my room better than any of the other speakers I have previously owned. Consequently, the bass creates the perfect cohesive foundation for the midrange and treble in my listening room. John was also nice enough to loan me an Audio Research Reference CD-9 Digital Player, Audio Research Reference 6 Preamp and AudioQuest Fire Interconnects.

The synergy of the Vandersteen speakers and mono amps, combined with the Audio Research preamp and digital player, has resulted in the highest sound quality I have ever heard and it is occurring right in my non-dedicated listening room!

The Vandersteen/ARC/AQ system is producing amazing tonality. Midrange body, weight and bloom. Tremendous ease without a hint of solid state or digital edge. Vocals and instruments are holographic and float in space with wonderful separation between vocal and instrumental lines. The soundstage, depending on the recording, can be very wide and deep, extending well beyond the walls of my room. Bass is very robust and lifelike with wonderful texture and goes down to subterranean levels. Deep pipe organ notes are felt to the core. It feels like I'm in a cathedral. Female jazz vocals are as smooth as silk with zero sibilance. Trumpets really have that blatt sound. Violins sound like wooden boxes, not glass ones. Dynamics are lightning fast and powerful. The pure silver AudioQuest cabling enhances detail and nuance with no additional treble or midrange brightness.

To sum it up, for the first time ever, I am totally content with the world class sound quality I am enjoying. The system sounds so lifelike, I forget about the components and become totally immersed in the music. I often listen very late into the night, mining my music collection to rediscover old favorites. Mr. Vandersteen, you hit it out of the ballpark with this speaker/amp combo!

JimboJumbo's picture

There's a bit of resonant activity around 4 or 5 Khz and also 18 Khz in the CSD plot.

Step response is spot on; see my comments on the Wilson audio test; https://www.stereophile.com/content/wilson-audio-specialties-alexx-loudspeaker#comment-576416

Other stuff looks pretty good; but then for $62K it should be.

JimboJumbo's picture

Slew rate?

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