Loudspeakers are all pretty much the same and have been for years. Conventional drivers in varying arrangements with passive crossovers that deliver sound from focal points that emanate out into the room in a spherical wave. This can be a very effective way to reproduce sound and works quite well when properly implemented, but there are other options. Line sources are not nearly as common as point source speakers. The subject of this review is the Wisdom Audio Sage Series, a large line source in-wall speaker system designed for those looking for the absolute sound performance without the loss of floor space found with typical speaker systems.
The system reviewed was installed in one of the Sound Components demo rooms in Coral Gables, Miami, which is where I conducted this logistically difficult review. The system consisted of three L150i for the front left, right and center ($13,300 each); four P20i surrounds ($2,225 each); the STS subwoofer ($10,000) and the required system controller the SC-1 ($6,500). Mounting hardware added a few thousand more to the system, bringing the total price for the speakers and controller to $72,500.
Line sources have been around for years but aren't very common. They do however have a small but highly dedicated fan base. This is because the propagation of sound from a point source spreads out in all directions, like a sphere, and is subject to reflections from the floor and ceiling. In a line source, the sound spreads out as an ever-expanding cylinder and eliminates these reflections. Basic calculus also shows us that since the sound expands in one plane (relatively), the sound pressure level drops off much less from a line source than a point source. This can be appreciated by walking around the room with each of the two types of speakers playing. Point sources drop off quickly in volume with distance while line sources do not. This, coupled with the elimination of reflections from the ceiling and floor make for a much larger sweet spot. No longer do you need to have your head in a vice for the perfect sound; the perfect sound is everywhere in the room.
The Wisdom Sage series are unique and revolutionarily designed loudspeakers. Rather than conventional drivers handling a limited range of the audio frequency spectrum, Wisdom has created a planar magnetic driver that does things no conventional driver could dream of. First off, the driver surface is huge, and I mean huge - 75 inches long. The entire surface of this panel is the voice coil as well, so heat is dissipated at an unthinkable rate and the driver is almost impossible to damage or blow even with the most powerful amplifiers. The panel is also ultra-light, making it far more responsive than traditional dome tweeters for amazing clarity and dynamics as well as efficiency. They offer a fixed resistive load to the amplifier, making them the easiest load any amplifier will ever see. These planar magnetic films are then housed between super strong Neodymium magnets, giving high sensitivity with extremely rapid and tight control.
The L150i's consist of two cabinets: one for three 24-inch planar magnetic panels, the other houses 12 proprietary woofers. This allows for a very large line source. The SC-1 controller houses the active crossover and outputs high pass and low pass channels to your (or Wisdom's) amplifiers. The woofer cabinet uses two channels of amplification: each drives 6 woofers while the third channel of power covers the planar magnetic panel. Frequency response goes down to 30Hz with a single crossover point at 275Hz. The L150's sport a 96dB efficiency rating at 2.83 Volt/Meter sensitivity. The planar magnetic panel covers frequencies from 275Hz to 20kHz so there are no problems induced by crossovers in the midrange.
The P20i's utilize two of the same bass drivers and extend down to 40Hz. A much smaller, folded two inch planar magnetic tweeter handles everything above the 650Hz crossover point. The two inch square driver is partially hidden behind an acoustic 'lens' that optimizes dispersion of the high frequencies while allowing the midrange to pass freely. The seemingly small tweeter can still output massive volume and dynamics thanks to its large surface area that allow it to keep pace with the bigger models in the line. Despite the smaller size, the P20i's still manage a relatively efficient 87dB at 2.83Volts/meter sensitivity.
The workhorse of the low end in this system is the Wisdom Audio STS subwoofer. When I first saw this piece at CEDIA I immediately fell in love with it. First off, it's huge; thus the STS name, which is short for Steamer Trunk Subwoofer. Employing two 15 inch woofers and a port that can be located on any of three sides, the STS can be used in the room or installed in the ceiling, floor, closet or wall. This thing is a beast, offering 101dB efficiency at 2.83Volts/Meter, yet is capable of outputting 130dB at 20Hz. The STS can handle up to 5,000 Watts into its four-Ohm load.
Every Wisdom system requires the SC-1 system controller. The SC-1 is an active crossover and DSP processor utilizing the top of the line Audyssey Pro room correction. Passive crossovers, meaning a crossover downstream from the amplifier, have inherent problems. By dividing the frequencies to the different drivers, they effectively rob power from the amplifier and make speakers less efficient. Putting the crossover before the amplifier means that each channel of the amplifier only has to amplify the spectrum of frequencies that its driver is reproducing. This effectively lessens the work of the amplifier and improves performance, albeit at a price. Active speakers require a separate channel of amplification for each driver, adding to the expense of such systems.
The Wisdom Sage series speakers are active, meaning the crossover is powered and in line before the amplifiers, so each L150i requires three channels of amplification and the P20's need two. In the setup I demoed for this review, the rest of the system consisted of a Classe's CT-SSP AV preamp, three Mark Levinson No 533H amplifiers, one for each of the L150i's and two Anthem A5 series amplifiers for the four P20i's. A pro-level Crown amplifier outputting some 3,000 plus Watts powered the STS subwoofer. The rest of the system was pretty simple with a Mac Mini server for digital music and a Kaleidescape for Blu-ray. The entire system was wired with Transparent cable. The planar magnetic drivers of the main speakers were tucked up against the sidewall of the room with the bass modules inside them. The front speakers were hidden behind fabric, as were the surrounds. Despite the room's relatively small 15-foot width, it still played host to a 13 foot 2.35:1 acoustically transparent screen, which covered most of the front wall of the room during theater applications.
I won't lie to you, I have done the setup of a Wisdom system, and as each speaker is bi or tri-amplified, there is a ton of wiring and equally as many chances to make an error in that wiring - so please, let your dealer install your system. Once they are installed they can be covered with a host of grill options from Wisdom or covered completely with a fabric wall.
I first cued up Peter Gabriel's new album Scratch My Back (EMI) and started off with a favorite track in "Listening Wind." The piece showed amazing space and air while the bottom end was deep yet tight and frankly palpable, especially at higher volumes. Vocals were smooth and clear while the strings came in and out with total independence. The balance was perfect from top to bottom. "My Body is a Cage" showed the amazing power a piano could have to a level I have almost never heard from a stereo system; the lone notes attacked and decayed perfectly with the power and weight I expect of a live piano. Bass lines again were completely clean and musical. The space of this piece was so impressive, vocals had exceptional separation and hung in the air entirely on their own.
Read more about the performance of the Wisdom Audio Sage Series on Page 2.