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Fig.1 shows the spectrum of the Velodyne reproducing a 100Hz sinewave at 2.83V, equivalent to just under 1W. The spike reaching 0dB at 100Hz is the fundamental; two additional spikes at 100Hz and 150Hz can also been seen. These are the second and third harmonics: while higher than specified, at a little above –56dB, 0.15%, these are still very low in absolute terms. For comparison, fig.2 shows the spectrum of the B&W Silver Signature reproducing a 100Hz tone at the same 2.83V level. The second harmonic here is more than four times as high as that of the DF-661, reaching the –40dB level…
Sidebar 1: Specifications
Description: Three-way, stand-mounted, reflex-loaded loudspeaker. Drive-units: 1" (25mm), ferrofluid-cooled metal-dome tweeter; 6" (152mm) spun-aluminum laminated–cone midrange unit; 6" (152mm) spun-aluminum cone woofer. Crossover frequencies: 700Hz, 5.5kHz. Electrical crossover slopes: 3rd-order low-pass to woofer, 18dB/octave; 2nd-order high-pass, 2nd-order low-pass, to midrange unit, 12dB/octave; 4th-order high-pass to tweeter, 24dB/octave. Frequency response: 60Hz–20kHz, +2dB. Sensitivity: 88dB/W/m (2.83V). Nominal impedance: 6 ohms. Distortion: !x0.1% at 1W…
Sidebar 2: System context
Power amplifiers used to drive the Velodynes were either a pair of Mark Levinson No.20.6 monoblocks or a YBA 2 HC, while the preamplifier was variously the Melos SHA-1 headphone amplifier used as a line-stage, the YBA 2, the Classé Six Mk.II, the remote-controlled Mark Levinson No.38, or the very promising McCormack TLC-1 buffered passive control unit. A Mod Squad Phono Drive EPS amplified LP signals from a Linn Sondek/Cirkus/Trampolin/Lingo/Ekos/Arkiv setup sitting on an ArchiDee table. Digital source was a Mark Levinson No.30 driven by a Mark Levinson No.31…
Sidebar 3: A Little Boost Can't Hurt
As the DF-661's lean sound quality appears to be due to a simple equalization problem, I tried boosting the region below 500Hz with an Audio Control Richter Scale bass equalizer. Though a slight glare remained in the mid-treble, the EQ both eliminated the speaker's intrinsically lean quality and produced usable bass extension to 60Hz or so. The price paid, however, was that the woofer was now working much harder than the other units. High-level kickdrum was accompanied by significant wind noise from the port, for example, as were low-frequency warble…
Sidebar 4: Sensitivity or Efficiency?
If there are areas of loudspeaker performance which are as consistently confused as efficiency and sensitivity, I've yet to discover them. Audiophiles almost universally talk about a loudspeaker's "efficiency" when what they really mean is its "sensitivity": how loud it will go for a given input level. Why is there this confusion?
Historically, dating from the days of tube amplifiers, when power outputs were very limited and the question of power transfer to the loudspeaker was more significant, there is "efficiency." Strictly speaking,…
Sidebar 5: Measurements
The Velodyne's sensitivity, calculated using B-weighted noise, was basically to specification at 87.5dB/W/m. This is quite high, implying that the DF-661 will go loud with relatively moderately powered amplifiers, provided they can deliver high current. The speaker's plot of impedance magnitude and phase (fig.1), measured using the magazine's Audio Precision System One, indicates a relatively demanding load over most of the audio band, with a minimum value of 3.2 ohms at 235Hz. Note also the slight wrinkles in the traces, between 400Hz and 500Hz, and at 26kHz.…
Beautiful listening in Munich. Photo: Michael Lavorgna
Last week, AudioStream’s Michael Lavorgna and InnerFidelity’s Tyll Hertsens shared their insights and images from the 2013 Munich High End Show. In case you missed it, Michael, Tyll, and AnalogPlanet’s Michael Fremer, provided further coverage at their respective sites. I highly recommend checking out their show reports. It makes up some of the best show coverage I’ve read anywhere—a testament not only to my colleagues’ passion and skill, but also to the utter brilliance of the Munich High End Show, which continues to set the…
Register to win a Focal XS Book Music System (MSRP $299.00) we are giving away.
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Despite a recurring and subtly bothersome perirectal abscess, I was committed to making this a good weekend. My life had been devoid of concerts and bars due to my renewed vow to frugality, but an endless stream of incredible live music in NYC this weekend could not and would not be ignored.
Anamanaguchi, Irving Plaza Power by Klipsch, Friday, May 17th, 2013
Last Tuesday, May 14th, 2013, Nintendo-sound-chip hackers Anamanaguchi released their turbo-charged twenty-two track album Endless Fantasy. The following Friday, May 17th, I attended their record release show at Irving Plaza…
The loudspeaker designer's art has changed radically over the past 20 years. Although the goals are largely the same, today's designer employs tools and techniques unimaginable two decades ago. Computer modeling, powerful and affordable FFT machines, and sophisticated new driver technologies are just a few of the advantages enjoyed by the modern designer. The high-tech result is a vastly better loudspeaker—even inexpensive products today are significantly better than those of even five years ago, never mind 20.
The new Genesis III loudspeaker shows just how sophisticated the designer's…