Genesis makes some very large systems, with midrange and treble drivers arranged on large panels and, usually, separate bass cabinets. These designs demand…
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In Stereophile's "Recommended Components," most full-range Class A speakers—and even some in Class B—are behemoths. Some are tall, some are wide, some are deep, and some are just plain big. Most of us would find such no-compromise devices physically imposing and visually distracting in our listening rooms. Putting aside the infamous "Spousal Acceptance Factor," how can you ignore such speakers' presence and concentrate on the music?
Description and setup
The Genesis 500 is a complex system of seven drivers covering four frequency bands. The lowest frequencies are served by three metal-coned 8" drivers, servo-controlled and powered by an in-built 500W switching power amp. Above 95Hz or so, the woofers cross over to a 6.5" aluminum-cone "midbass coupler," which in turn crosses over at 300Hz to a 5.5" titanium-cone midrange mounted in an open-back enclosure. The very top end, from 3.6kHz up, is supplied by a pair of 1"-diameter circular planar ribbons aimed fore and aft. Consequently, from 300Hz up, the Genesis 500…
The Genesis 500 is a complex system of seven drivers covering four frequency bands. The lowest frequencies are served by three metal-coned 8" drivers, servo-controlled and powered by an in-built 500W switching power amp. Above 95Hz or so, the woofers cross over to a 6.5" aluminum-cone "midbass coupler," which in turn crosses over at 300Hz to a 5.5" titanium-cone midrange mounted in an open-back enclosure. The very top end, from 3.6kHz up, is supplied by a pair of 1"-diameter circular planar ribbons aimed fore and aft. Consequently, from 300Hz up, the Genesis 500…
Listening
Although it took weeks to titrate the position and controls just right, there was no doubt about these speakers right out of the box and arbitrarily plunked down. As with the EOS, the Genesis 500 sounded musical at first turn-on, with an honest midrange and a wide frequency response. For a while, it seemed as though the 500 was a bit laid-back in its presentation, but that was due to a number of external factors. First, most of the initial listening was done with the Sim Moon W-5 amp, which also has a laid-back character. Second, even after switching to the Bryston 7B-ST, and…
Although it took weeks to titrate the position and controls just right, there was no doubt about these speakers right out of the box and arbitrarily plunked down. As with the EOS, the Genesis 500 sounded musical at first turn-on, with an honest midrange and a wide frequency response. For a while, it seemed as though the 500 was a bit laid-back in its presentation, but that was due to a number of external factors. First, most of the initial listening was done with the Sim Moon W-5 amp, which also has a laid-back character. Second, even after switching to the Bryston 7B-ST, and…
Occasionally, however, something would upset the precious illusion and the 500s would call attention to themselves. I'll take a risk here and suggest that the culprit is the midrange baffle arrangement. Genesis touts the 500 as a dipole from the midrange up. Technically this may be so, but the midrange driver is mounted at the front of a short tunnel. Thus, it radiates freely to the front while its rear radiation passes through the chamber. Close listening reveals that the rear sound is decidedly lacking in the upper midrange as compared with the front. I suspect that, at the listening…
Sidebar 1: Specifications
Description: four-way loudspeakers with powered, servo-controlled woofer. Drive-units: two 1" round ribbon tweeters, one 5.5" titanium-cone midrange driver, one 6" aluminum-cone midbass coupler, three 8" metal-cone woofers. 500W G-SAT switching amplifier for the bass drivers. Crossover frequencies: 95Hz (adjustable), 300Hz, 3.6kHz. No frequency response, impedance, or sensitivity specified.
Dimensions: 44" H by 11" W by 22" D. Shipping weight: 242 lbs/pair.
Serial numbers of units reviewed: 550121, 550122.
Price: $11,500/pair. Approximate number of…
Sidebar 2: Associated Equipment
Analog source: Heybrook TT2 turntable, Rega RB300 tonearm, Koetsu Black/Gold phono cartridge.
Digital sources: Audio Alchemy DDS•Pro/DTI•Pro 32/DDE V3 with Audio Magic I2S cables, California Audio Labs CL-20 DVD/CD player, Burmester 970/969 transport/DAC.
Preamplifiers: Klyne 6L3.3P, Sim Moon P-5, Sonic Frontiers Line-2, Line-3.
Power amplifiers: Bryston 7B-ST monoblocks, McCormack DNA-1, Sim Moon W-5, Sonic Frontiers Power-2.
Cables: Interconnects: Cardas Cross and Golden Cross, Straight Wire Virtuoso, JPS Superconductor Super-2 Balanced.…
Sidebar 3: Measurements
The well-finished Genesis is quite sensitive, at an estimated 89.2dB(B)/2.83V/m. To judge from its plot of impedance magnitude and phase against frequency (fig.1), however, it needs to be driven by an amplifier capable of healthy current delivery. With an average impedance of around 3 ohms and a minimum of 1.73 ohms between 400 and 500Hz, where much of music's power is concentrated, the 500 makes extreme current demands on amplifiers.
Fig.1 Genesis 500, electrical impedance (solid) and phase (dashed) with controls at recommended positions. (2 ohms/…
This suckout can also be seen in the speaker's response averaged across a 30 degree window on the tweeter axis (fig.4), which is a reasonably high 42" from the floor. It looks suspiciously like an acoustic cancellation problem, perhaps from the dipole loading of the midrange unit. I note that KR did find the speaker's balance laid-back; this behavior might well be the cause.
Fig.4 Genesis 500, anechoic response on tweeter axis at 50", averaged across 30 degrees horizontal window and corrected for microphone response, with the complex sum of the nearfield woofer, midbass coupler,…
Below 1kHz, the on-axis notch actually increases in frequency well to the speaker's sides, but is joined by another notch an octave lower. Again, this off-axis behavior will tend to make the speaker sound laid-back, or even colored in very reverberant rooms. In the vertical plane (fig.8) the 800Hz notch is ubiquitous, other than at angles lower than 10 degrees below the tweeter axis. But other than that and the tweeter's limited top-octave dispersion, the balance doesn't change very much with listener height. Only when the listener is standing does a classic crossover notch develop, revealed…
The step response on the axis of the rear-facing tweeter (fig.11) shows that the rearward radiation is indeed 180 degrees out of phase with the Genesis' forward radiation—in other words, dipole behavior. But note that, because the rear radiation in the midrange comes from the front-mounted drive-unit cone and not from a separate unit, as with the tweeters, this follows the HF output by about a millisecond. This is not relevant to the speaker's perceived sound quality, however; these outputs will be well integrated by the room acoustic by the time they reach the listener's ears. Note that the…