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Equipment Review

August 2000

Soliloquy 6.3 Loudspeakers

by Marc Mickelson


Review Summary
Sound Sweet and robust, but with ample sparkle on top to convey the air and space of a recording; bass is powerful and may require extra setup experimentation.
Features Dual woofers and soft-dome tweeter; 90dB sensitivity and 8-ohm impedance; choice of three real-wood veneers; spikes are "ingenious."
Use Need to be aimed directly at the listening position to avoid sounding overly mellow and indistinct; getting them out from room boundaries can help tighten up the bass, as will the installation of the spikes.
Value Competitive with more expensive speakers; tube and solid-state friendly.

Fixtures at every audio show I've attended, Soliloquy loudspeakers have a growing reputation among my ilk of audiophile -- tube lovers, that is. I understand that Cary Audio's Dennis Had designed the original two Soliloquy speakers, which have been long discontinued, and then sold the rights to the name Soliloquy to the current owner, Bernie Byers, who has bulked out the line to include floorstanding and minimonitor speakers, a powered subwoofer, and center- and rear-channel speakers.

The newest Soliloquy speaker, the 6.3, is the flagship of the line. The 6.3 is a "2.5-way" design that uses two 6.5" poly-fiber woofers along with a silk-dome tweeter. The crossover point from tweeter to woofers is 2.7kHz @ 12dB per octave, but the lower woofer of the pair is also equalized 3dB starting at 100Hz, making the 6.3 more than a two-way design but less than a three-way. All of the drivers are magnetically shielded, so there's no worry if you need to place the speakers near a TV or computer monitor.

As we reviewers are practically programmed to do, I rapped my knuckles on the 6.3's cabinet and heard only a very dull "thuk." This is certainly the byproduct of stout internal bracing and some overall heft to the speakers, which weigh in at 100 pounds each. Thus the 6.3s are not small speakers, measuring 44"H x 9"W x 13"D and delivering a quoted frequency response of 25Hz to 20kHz. Sensitivity is rated at 90dB/W/m, and impedance is stated as a benign 8 ohms. The combination should spell for an easy load for most tube amps, including SET designs of more than a handful of watts of power. Around back are a large flared port and two pairs of good-quality gold-plated binding posts. Soliloquy has thought to include a pair of gold-plated jumper bars for those who won't want to bi-wire or bi-amp. The review pair of speakers came in a maple finish, which was very light in color. Rosewood and cherry are also options, and neither adds to the 6.3s $2995-per-pair price.

In the unique-features department, the bottom plate of each speaker is actually a thick metal plate with four "tabs" into which the spikes thread. This configuration makes installing the spikes a snap, even if you do it by yourself. The spikes are knurled on one end and thread in from the top; all you need to do to get them started is tilt the speaker a bit and then screw them in. Leveling the speakers is equally easy because you can simply turn the spikes from the top cap of each spike. This system is ingenious, and even though you see the spikes, the whole package looks very good.

Systems and setup

I used the 6.3s initially in place of a pair of Merlin TSM-SEs and connected to the Pathos Classic One integrated amp, a Panasonic SL-S321C portable CD player acting as source. After a few weeks in this setup, I moved the 6.3s into the main listening room, where they were paired with Lamm ML2 monoblocks, a Lamm L1 line-stage preamp, Mark Levinson No.39 CD player, and Bel Canto DAC1. I also used Taddeo Digital Antidote Two and Ortho Spectrum AR-2000 devices directly down the analog stream from the digital gear. Interconnects and speaker cables were from JPS Labs (Superconductor 2 and NC Series) or TARA Labs (Air One), with power cords from JPS Labs, TARA Labs, API, Audio Magic and ESP. I also used a PS Audio P300 power regenerator for the preamp and digital gear and a Richard Gray's Power Company for the amps. Later on in the review period, I received a Mark Levinson No.383 integrated amp for review, and this was pressed into use with the Soliloquy 6.3s as well.

As I was primarily running in the speakers when they were in the more modest system, I didn't pay much attention to positioning. I merely put the 6.3s where the Merlins had been on their stands -- roughly 26" from the back wall and the same from the side walls. Once I put the 6.3s into the reference system, however, I found that I had to futz with them to get them to sound anything less than very mellow overall and too ripe in the bass. I thus moved the speakers well out into my 12'x24' listening space and away from the side walls, and I toed them in directly at my listening position. I tweaked a bit after this, but I ended up with the speakers 62" from the back wall and 24" at the center point of the cabinet side from the side walls. This position gave me the best balance of top-end air and bottom-end growl, although it certainly didn't change the speakers' character completely. Spiking the speakers also helped tighten up the bass, as it normally does. However, using the grilles, which complement the speakers visually, is a no-no for critical listening as they obscure the sound a slight bit.

On their own

The Soliloquy 6.3s speak with a distinct voice that's on the warm, robust side of things, which is why properly positioning the speakers is so vital. When the speakers are not toed in enough, they sound overly soft and indistinct. But when things are right, the 6.3s sound sweet and inviting, both of which happen to please me more than analytical and, gulp, sterile. Their bass only adds to this characterization -- it is powerful, able to fill a large room or overpower one that's too small. Through the mids, the 6.3s are full and round, fleshy is probably the best way to describe them, while the top end is friendly in its middle and lower regions and open at its very height, giving the music an ample amount of sheen.

Have I now blown the review by summarizing the speakers in one paragraph? Not even close. The 6.3s have more depth of character than a single paragraph can convey. Robin Holcomb's eponymous debut disc [Elektra Musician 9 60983-2] is a fave of mine for Holcomb's truly poetic lyrics as well as her atmospheric music. The synth tones on "The American Rhine" display plenty of nuance and show themselves to be part of the inner detail of the sparse mix with the Soliloquy 6.3s, which reproduce the decay of the tones into the soundstage very well. The low-frequency synth work on "So Straight and Slow" reveals overtones that minimonitors will miss, but the 6.3s are easily able to dig them out of the mix. "The 6.3s seem made for this disc," my notes read.

However, on the airiest of recordings, like the well-recorded discs from Turtle Records, the 6.3s show an inability to define the very furthest corners of the soundstage -- although having heard these discs at the CES a few times, I can say the 6.3s also avoid the problem of sounding tipped up in the treble. The 6.3s cast a very believable and populated soundstage, one that fills the room with sound no matter what the recording. There's an inherent smoothness to the 6.3s' sound, probably due to the soft-dome tweeter used. In fact, the 6.3s' treble reminds me of highs from my departed ProAc Response Fours, which also use a soft-dome tweeter. And like the ProAcs, the Soliloquy 6.3s' top end is able to convey the sheen and air on recordings like Tony Overwater's Up Close [Turtle Records 198119], but not in a way that sounds emphasized or unnaturally tizzy. The 6.3s are always smooth and composed, and they dare you to toss anything at them.

And so I did, feeding them a steady diet of Rollins Band, including Weight [Imago 21034] at very high listening levels. Anyone who thinks that SET amps can't do headbanging music should hear "Disconnect" played on the Lamm/Soliloquy combo. It rocks, providing a good low-end foundation for the screeching guitars. In fact, my room began to pressurize long before the sound could turn glassy or hard -- which, in truth, my ears couldn't hang in to test. "Shine" is a "where's the subwoofer" tune over the Soliloquy 6.3s, its get-your-crap-together-now message being great to hear loud.

And you can probably tell where I'm going from here. Once the Levinson No.383 showed up, in it went with the 6.3s, and the sound was even more forceful, the solid-state integrated bringing some added discipline. Although the 6.3s were happy with the Lamms and even played loudly with the 15Wpc AES Super Amp, they sounded more controlled with the 100Wpc Levinson integrated and didn't sacrifice their sweetness in the process. I would've loved to hear the 6.3s with the Simaudio W-5 amp I reviewed earlier in the year. The W-5's combination of immense power and bass control might make for an ideal match.

In terms of tubes, if your amp of choice has plenty of detail and transparency, you'll be more than OK with the 6.3s. If it is a dark, tubey-sounding amp, you may have too much of the tonal richness that's often a good thing. Some may prefer this sort of sound, especially with a less-than-perfect digital front-end, but I would worry about missing out on detail and space, not to mention overdosing on sweetness.

Silverline vs. Soliloquy

Two speaker brands often considered by tube-loving audiophiles are Soliloquy and Silverline. We have reviewed the Silverline Sonata and Sonatina models, and I have heard both at length. In fact, the Sonatas were here along with the Soliloquys, waiting patiently in the corner of my listening room for their time at the business end of the amps.

Both speakers are easy to drive, although the Soliloquys are subjectively more efficient, playing louder at the same volume level. One other big difference is their price: the $5995 Sonatas are twice the 6.3s' price. The main sonic differences center around the vocal region, which is more chesty over the 6.3s than the Sonatas. Even female vocals, like Ani DiFranco singing "Angry Any More" from Up Up Up Up Up Up [Righteous Babe RBR013-D], take on a more resonant quality over the Soliloquy 6.3s than the Silverline Sonatas. In terms of bass, the single 10" woofer of the Sonata cedes a little heft to the two 6.5" drivers of the 6.3, but it makes up for it with slightly greater impact, the kickdrum whomps on Keith Richards' Main Offender [Virgin 86499 2], for example, sounding a bit more taut. The Sonatas' treble is a bit more light-filled than the 6.3s', which in turn has a bit more energy at its uppermost range.

Both of these are fine speakers, and which one you pick will depend a great deal on the amp with which they are used. Even though I suspect most dealers will demo the 6.3s with tubes, ask to hear them with solid state too. I also know that Soliloquy has achieved very good sound at shows with Art Audio's Jota, a SET design that doesn't give in at either frequency extreme.


As I am reviewing a piece of audio equipment, I often think about who would find it of interest. In the case of the Soliloquy 6.3s, although their benign impedance and relatively high quoted efficiency will catch the eyes of tube lovers, I found the speakers to sound their best with the solid-state Mark Levinson No.383 instead of the highly seductive and SET-powered Lamm ML2 amplifiers. Why? Well, the 6.3s needed the added power and oopmh of the No.383 to help them boogie in my room. Once the 6.3s were optimally set up and powered, they reproduced tones and overtones with grace and beauty, threw a room-filling soundstage, and had bass power and weight to burn. In fact, their bass really benefited from the added control the No.383 brought to them, turning the lowest regions of the 6.3s into a mark in the positive column, especially given the speakers' price.

However, keep in mind that I was limited in terms of the amps with which I could use the speakers. I suspect that tube amps from, say, ARC or Sonic Frontiers (or Art Audio, as I mentioned) would sound good with the 6.3s and would make some listeners very happy. Keep an open ear and mind with these speakers and you'll probably not only enjoy the final destination but also the journey that got you there.

...Marc Mickelson

Soliloquy 6.3 Loudspeakers
Price: $2995 USD per pair.
Warranty: Five years parts and labor.

Soliloquy Loudspeaker Company
2613 Discovery Drive, Building A
Raleigh, NC 27616
Phone: (919) 876-7554
Fax (919) 876-2590

E-mail: info@solspeak.com
Website: www.solspeak.com

Soliloquy responds:

Thank you to Marc Mickelson for a fair and comprehensive assessment of our Soliloquy model 6.3. We especially appreciate the fact that he went beyond his stated preferences for low-powered tube amplifiers to discover that solid-state amplifiers work equally well with our speakers. In the case of the very bass-extended 6.3 model, a high-current solid-state amp will indeed provide better results most of the time, just as he found. Marc was also right suspecting that the Simaudio Moon W-5 would have made a superb match. We own the Simaudio Moon W-3/ P-5 combo as our in-house solid-state reference and find it to provide much better low-end control than most tube amps are capable of.

This is the very point we would like to stress for prospective buyers of Soliloquy loudspeakers. While it is true that we personally favor tubes for their musicality and do own select amplifiers by Cary Audio and Art Audio, most of our customers use solid-state amplifiers for obvious reasons: They tend to be more affordable, require less care and work with a wider variety of speakers.

Consequently -- with the exception of one -- none of our Soliloquy models were voiced to favor one amplifier topology over another. If we only designed special tube-compatible loudspeakers, our appeal would be severely limited to a very small audience. Our ambition in fact is quite the opposite: to offer fairly priced, contemporary-looking, furniture-grade speakers that are compatible with the widest variety of amplifiers.

In closing, a speaker that is tube friendly is by nature also solid state friendly. Thus, none of our models make undue demands on an amplifier and are easy loads to drive. This design parameter allows prospective buyers to keep or select medium-powered amplifiers of sonic refinement and musicality rather than requiring brute muscle amps that tend to cost a lot and often sacrifice nuance and shade for raw power and control. It doesn't matter whether these amplifiers are solid state or tube, although, like Marc found, if tubes are to be used with our top-line 6.3, a higher-power push-pull amplifier of 100Wpc will provide better results than most single-ended designs.

Thank you for a chance to comment on your review.


Bernie Byers
Soliloquy Loudspeakers

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