The show held two special treats this year. I listened and talked with both the audio industry legend, Bob Carver, he of Phase Linear and Sunfire fame, and Prudence (Farrow) Bruns, she of the Beatles' "white" album fame.
Thin and Tall
Carver said he always liked ribbons since the famous Apogee
loudspeakers impress him so much. His loudspeakers should be about 40 Hz to 40
kHz and cross over at high 800 Hz. The crossover will function like a first
order one. Carver expects about 96dB/W/m efficiency. A frequency response
greater than 20 kHz helps that lock images into place.
The demo room included a flat Sunfire Subrosa sub along the front wall. It had dual 10" hi-back EMF drivers powered by a 2700-watt tracking down converter amplifier made famous by Carver while he was at Sunfire. A sub-woofer adds impact and majesty, which he designed to be as flat as possible. He "loves lots of power." The bass amplifier provides 2000-watts and the arrays can handle 2600-watts per side. Using multiple drivers increases not only sound pressure levels, but also efficiency. The current prototype at the show was bi-amped with had four amplifiers, with 600 1200-watts per side. Using multiple drivers increases not only sound pressure levels, but also efficiency. The current prototype at the show had four amplifiers, with 1200-watts per side.
Next, the output impedance of a tube amplifier is not zero.
It follows the impedance characteristics of the driver. Music doesn't have
to be flat to sound good. "A flat curtain of sound," Carver said, "means
the beautiful space collapses." The facsimile reproduction, because a real
one is not possible, only makes "something that could have existed in time
and place." This is deep stuff here – when you think about it. According
to Carver, the facsimile reproduction is more enjoyable than the flat curtain
of sound that many amplifiers provide.
Confirming what Peter van Willenswaard reported in "Tubes Do Something Special," Carver said tubes watts are indeed more powerful than solid-state ones. The man in the audience said he heard twice as much, but Willenswaard found that tubes provide about five times more power than their rated watts. Carver's new amplifiers will use KT-88s and the new KT-120 tubes, which he said are KT-88s at twice the power. The new Black Beauty monoblock model sports three sets of KT-120 tubes for 305-watts into 8 Ohms and 290 into two. The Cherry red model uses KT-88 tubes for 200-watts into 8 Ohms and 215 into two. Both have a feedback control switch for classical (vintage tube) or contemporary (more modern) sonic signatures and output tube tester. The renown Dick Olsher is right now reviewing the new Cherry 180 models for Enjoy the Music.com. So check back for his review coming soon!
Also planned for his new loudspeaker system is an active
crossover utilizing tubes. In the demo system was a Purity Audio tube
pre-amplifier. The slaphappy room had no acoustic treatments other than a few
orchids. Carver did however, deploy four graphic equalizers tailored to the
driver set. On Patricia Barber's "Café Blue," the huge soundstage
easily recreated a facsimile of her bar scene "that could have existed in
time and place."
After listening first to Carver about audio engineering and
then to Prudence about her life engineering experiences with the Beatles,
meditation and yoga, it would have been appropriate to spend the rest of
AXPONA listening to the Beatle's "white" album on Carver's new system.
Alas, I did not. Perhaps I will save that for my own comeback. Already looking
forward to AXPONA 2013!
This year, the show was exceptional for several reasons! Of course, it is thrilling to see such incredible looking, sounding and expensive systems. I also enjoyed the company of tweaking audiophiles on the drive there, at a room party, in a question and answer session with other writers and at dinner. Members of my audiophile club (Tampa) gathered in the hallways, at breakfast and dinner to compare notes; nothing like having a bunch of mostly middle-age techno geeks to share one's love of movies, music and home reproduction systems.