Gradient Revolution loudspeaker Page 2
The stated sensitivity of the Revolution is 86dB/W/m; I estimated a figure of 82dB, which is pretty low for a three-way loudspeaker. The partnering amp should therefore be able to deliver at least 100W into 4 ohms. I didn't find the manufacturer's minimum power recommendation of 50Wpc adequate.
The input connections, which are located on the bottom of the bass enclosure, are bi-wire-ready—all you have to do is remove the jumpers. I found the increase in clarity to be well worth the cost of additional cable.
Once you park the speakers in their final resting places, be sure to remove the flat feet and experiment with the supplied spikes. For optimum bass precision, it's important to couple the speakers directly to the room's foundation. In my room, the spikes pierced the carpet, allowing direct energy transfer to the underlying concrete slab.
The owner's manual recommends an initial speaker placement similar to that of a planar, with the woofers and midrange/tweeter facing the listening area. A rear-wall clearance of 3.5'-6.5' is suggested. I ended up placing the speakers 6' from the rear wall, with the distance between the speakers about 7'. A slight toe-in gave me the most satisfying soundstage panorama.
I first heard the Gradient Revolution, driven by Quad electronics, at the 1994 WCES, where Pro Audio's Brian Tucker ushered me in to a fairly small (even by CES standards) room. I uttered a quiet "wow" as I eased myself into a chair next to designer Jorma Salmi, my attention caught by the clarity and definition of reproduced bass lines. I just wasn't used to that level of bass resolution from a box speaker. It wasn't long before Mr. Salmi explained that this was no ordinary box speaker.
A box speaker's greatest liability, and its toughest design challenge, is the box itself. The cabinet's panels flex and resonate, thus coloring and muddying bass reproduction. The sound output of a violin, for example, comes primarily from body resonances and the "F" holes. The violin's timbre is profoundly affected by the type and thickness of wood used, by the wood's grain orientation, and by other complex and not-so-very-understood factors. If violin making were an exact science, it would be easy to knock off Stradivarius copies whose sound qualities are identical to those of the originals. The mythical resonance-free loudspeaker enclosure does not exist. The most technology has to offer are means to dissipate or dampen resonances. Constrained-layer damping, sand-filled walls, and mass loading all quiet, but do not silence, an enclosure's sonic contribution. The best box speaker is one with no box at all.
With its aperiodic construction, it should come as no surprise that the Gradient's reproduction of cello and double-bass was a joy to behold. The mid- and upper bass regions were well-integrated, sounded open and airy, and had remarkable quickness and pitch definition. Rob Wasserman's Duets (MCA MCAD-42131) never sounded tighter or more detailed. Wasserman's expressive playing was given full scope.
The anechoic bass response of the Revolution is said to be flat to about 50Hz. However, deep-bass extension in my listening room leveled out at 40Hz, which was deep enough to do piano bass-lines justice. And due to the gentle bass rolloff characteristic of dipoles, even some of the power of the lowest octave shone through. The bass foundation of the organ accompaniment on Gary Karr's Adagio d'Albinoni (King K33Y 236) was fleshed out with reasonable conviction.
I occasionally ran into some definite midbass excursion limits. Check out the San Francisco Taiko Dojo's performance of "Tsunami," hot off the Rising Sun soundtrack (Fox 11003-2). The pounding drum beat should build to a chest-crushing climax at loud playback levels. Not with the Gradient—not even when driven by the Bryston 7B power amplifier. The woofers just didn't move enough air. The dynamic punch of the big drums was blunted, compressed to the point of politeness.
Although the dynamic range from loud to very loud was somewhat restricted, the Revolution ably handled music's microdynamics. Its ability to jump-start from soft to loud was noteworthy. The dynamic shadings of massed voices, as in Ariel Ramirez's Misa Criolla (Philips 420 955-2), were startlingly reproduced. The ebb and flow of the harmonic tapestry of each instrumental outline was lifelike.
As advertised, the Revolution proved itself adept at conjuring a spacious and stable soundstage. Image outlines were precisely focused within the confines of a panoramic stage. The perceived depth perspective was not only a function of the recording—as it should be—but was also dependent on the choice of partnering amplifier. Tube amplifiers worked best in this regard, most of my listening being conducted with Air Tight ATM-3 monoblocks, which, as an added benefit, also brought the midrange to life.