Brent has been a professional audio journalist since 1989, and has reviewed thousands of audio products over the years. He has served as editor-in-chief of Home Theater and Home Entertainment magazines, contributing technical editor for Sound & Vision magazine, senior editor of Video magazine, and reviews editor of Windows Sources magazine, and he also worked as marketing director for Dolby Laboratories. He's now on staff at Wirecutter.
You'd think that, after so many decades of speaker development, we'd have settled on a perfect driver complement. Actually, we kind of have. Once you look carefully at what kinds of speakers work best in most rooms, with most music, and for most listeners' tastes--and also tend to produce the best measured performance--you end up with three-way designs. These typically combine a dome or ribbon tweeter, a midrange driver in the four-inch range, and one or more 6.5- or eight-inch woofers. This isn't necessarily "the best," and I've heard many other driver configs that sounded world-class. But from what I've observed, this is the one that most dependably delivers a great result. One example of a speaker built like this is my usual reference, the Revel F206. Another is the new Prime Tower from SVS.
SVS made its reputation on building some of the best subwoofers you can buy...and making them affordable to the average audio enthusiast. Beginning with the Ultra Series speakers launched in 2013, the company started to get serious about frequencies above 80 Hz. The Ultra Series, while delivering astoundingly good performance for the price, was not inexpensive; the Ultra Tower cost $1,999 per pair. I expected a company that's best known for awesome, affordable subwoofers to deliver something a little more real-world in price. With the new Prime Series, SVS has done just that. The $999/pair Prime Tower is the top-of-the-line model; there's also the $499/pair Prime Bookshelf, $269/pair Prime Satellite, and $349-each Prime Center.
The Prime Tower conforms to the pretty-much-ideal driver complement I cited before: two 6.5-inch polypropylene-cone woofers, a 4.5-inch poly-cone midrange, and a one-inch aluminum-dome tweeter. It's a 3.5-way design, with each driver covering a different frequency range. The tweeter handles everything from 2.1 kHz and up. The midrange reproduces frequencies from 350 Hz to 2.1 kHz. The top woofer covers everything below 350 Hz. The bottom woofer comes in only at frequencies below 165 Hz.
Why not have both woofers covering the same range? Because if you did that, the distance between the lower woofer and the midrange would allow them to interfere with each other, reinforcing some frequencies and canceling others. With the 3.5-way design, the lower woofer helps out only in the bass, where its extra muscle is needed, and otherwise stays out of the way.
From the standpoint of visual aesthetics, the Prime Tower is just as well conceived. It's an eight-inch-wide speaker that stands just three feet high, so it can fit into an ordinary room without destroying the look, especially if you spend the extra $200 per pair for the gloss-black version (pictured here).
The Prime Tower imposes no special demands for setup: Just take it out of the box, screw in the spikes (or the rubber-coated feet if you have a tile or wooden floor), stand the speakers up, and plug 'em in.
Thanks to the use of a relatively small midrange driver and the low crossover frequency on the tweeter, the Prime Tower has broad, consistent dispersion through most of the audio band. Thus, it didn't make much difference whether I toed the speakers in to point straight at me or twisted them to point straight out into the room. However, the midrange sounded very subtly smoother in the former position, so I stuck with that. The balance between the mids and treble sounded just right with the grilles off, so as usual I didn't do much listening with the grilles on. (I did measure the speaker both ways, though--more on that later.)
As usual for my tower speaker reviews, I started with the speakers in the same position I use for the F206: front baffles 38 inches from the wall behind the speakers, speakers eight feet apart and nine feet from my head when I sit in my listening chair. This sounded good enough for starters. During my listening tests, I ended up pushing the speakers back one foot closer to the wall behind them. This gave the bass more oomph, at the expense of making the bass sound a bit boomier. Not that the Prime Towers needed more oomph in the bass; I just wanted to see how it would affect their tonal balance. Turns out that little bit of extra bass helped balance out the treble better, at least in my room, so I left them that way for the rest of my listening.
I started with my usual test rig: Krell S-300i integrated amp, ProJect RM-1.3 turntable with NAD PP-3 phono preamp, and Sony PHA-2 DAC/headphone amp connected to a Toshiba laptop that holds my music collection. This time, though, because I was starting to work on a review of some new electronics, I also used Classé Audio CP-800 and Krell Illusion preamplifiers and Krell Solo 375 mono-block amplifiers.
As luck would have it (for both my ears and the speakers), the very first thing I heard through the Prime Towers was "Bassics," from the new Levin Brothers LP, a recording that perfectly suited the speakers' capabilities. "Bassics" is a jazz trio recording with Tony Levin on electric upright bass, Pete Levin on piano, and Steve Gadd on drums. The bass largely carries the melody in this tune, and the Prime Towers beautifully portrayed all the subtleties of Tony's fingering, including little buzzes and intonation twists that aren't heard much his work with Peter Gabriel and King Crimson, almost all of which is on fretted instruments. The drums in Gadd's small jazz kit sounded truly lifelike; I could hear all the body and resonance of the kick drum and brushed snare as if they were right over behind the right speaker.
Realizing that I use way too much jazz in my reviews, I decided to put on something completely different: "Carry On" from Crosby, Stills, Nash & Young's 4-Way Street live album. In that circa-1970 era, recordings of rock concerts were rarely very good because the gear was primitive and the techniques usually casual. Yet "Carry On" sounded at least as good through the Prime Towers as I've ever heard it sound. The group's multiple guitars typically sound like an indistinguishable mess on this album, but the Prime Towers' clean and mostly uncolored midrange and treble let my ears pick out the individual parts to some degree. The same was true with the voices, which can be hard to pick out but weren't here. Voices also imaged surprisingly well, considering the source.
On a rock recording that does sound good, Band of Skulls' "Nightmares" from Himalayan, the Prime Towers' tonal balance sounded just right. They delivered the ample helping of bass that this tune needs to groove, without at all obscuring the treble. The distorted rhythm guitar had just the right amount of bite, but no annoying edginess.
Wondering how well-integrated the bottom woofer, the top woofer, and the midrange would sound, I put on the toughest bass integration test I know: the late Hawaiian vocalist and slack-key guitar master Rev. Dennis Kamakahi. Kamakahi's deep baritone and the detuned lower strings of his guitar tend to make a lot of full-size speakers sound bloated, and they tend to push the woofers and passive radiators of Bluetooth speakers into spasms. But on 'Ohana, an album Kamakahi did with his uke virtuoso son David, the Prime Towers didn't bloat or distort once on the challenging "Ulili'E" that opens the album, nor on my favorite of Kamakahi's tunes, "Ka'Opae."
Considering that anything wearing an SVS logo would probably find its way into more home theater systems than two-channel systems, I played a couple of movies through the Prime Towers, most notably 21 Jump Street. Its rock/hip-hop soundtrack pounds hard, especially in the intro, and on this soundtrack the Prime Towers pumped out so much powerfully deep bass that I never for a second wanted a subwoofer. I also found the dialogue clarity excellent, even in places where the music was really blaring.
Click over to Page Two for Measurements, The Downside, Comparison & Competition, and Conclusion...
Here are the measurements for the SVS Prime Tower speaker. Click on each photo to view the graph in a larger window.
On-axis: ±2.0 dB from 37 Hz to 20 kHz
Average: ±2.0 dB from 37 Hz to 20 kHz
Minimum 2.7 ohms/100 Hz/-24°, nominal four ohms
Sensitivity (2.83 volts/one meter, anechoic)
The first chart shows the frequency response of the Prime Tower; the second shows the impedance. For frequency response, two measurements are shown: at 0° on-axis (blue trace) and an average of responses at 0°, ±10°, ±20° and ±30° (green trace), all measured on the horizontal axis.
The Prime Tower has one of the flattest responses, on-axis and off, I've seen in a $1,000/pair tower speaker. There are some identifiable sonic characteristics, most notably a rise in response between 2.5 and 8 kHz that might make the speaker sound a little bright. But generally, this should be one of the most transparent-sounding speakers in its price range.
Note the rather sharp bass peak at 85 Hz. This didn't show up in my close-miked measurements of the woofers and port (which showed a more rounded peak), but it showed up in my ground plane and quasi-anechoic measurements, which is why I chose to include it instead of the close-miked measurement. The -3dB point on the ground-plane measurement is the 37 Hz number I included above; the close-miked measurement's -3dB point was 41 Hz. The rated -3dB response is 30 Hz. The level of this peak as shown on the graph is a best-guess (an unfortunate necessity of splicing a quasi-anechoic measurements to a ground-plane or close-miked measurement), which is why I don't include anything below 200 Hz in my frequency response deviance (i.e., ±2.0 dB) ratings.
These measurements were done without grilles, but I also ran an on-axis measurement with the grille. The fabric grille had a fairly large effect on the measured response, causing dips of max -4 and -6 dB at 3.6 and 5.2 kHz, respectively, as well as peaks of about +2 dB at 2.8 kHz and between 7 and 9.5 kHz.
Sensitivity of this speaker, measured quasi-anechoically from 300 Hz to 3 kHz, is 88.4 dB. You should get about +3 dB more output in-room, which means you'll need about 16 watts to hit 100-dB SPL. Nominal impedance is four ohms, and the Prime Tower drops to a low of 2.7 ohms. Thus, I recommend you use a high-quality A/V receiver, integrated amp, or separate amp. If you want to use a $300 A/V receiver, knock yourself out, but don't blame me if it keeps shutting itself off.
Here's how I did the measurements. I measured frequency responses using an Audiomatica Clio FW 10 audio analyzer with the MIC-01 measurement microphone, and the speaker driven with an Outlaw Model 2200 amplifier. I used quasi-anechoic technique to remove the acoustical effects of surrounding objects. The Prime Tower was placed atop a 28-inch (67-cm) stand. The mic was placed at a distance of two meters, and a pile of attic insulation was placed on the ground between the speaker and the mic to help absorb ground reflections and improve accuracy of the measurement at low frequencies. Bass response was measured by using ground-plane technique, with the microphone placed on the ground two meters from the speaker. I also close-miked the woofers and ports and summed that result for comparison with the ground-plane result. Bass response results were spliced to the quasi-anechoic curves at 240 Hz. Results were smoothed to 1/12th octave. Post-processing was done using LinearX LMS analyzer software.
When I start to put together my speaker reviews, I spend a lot of time listening to a lot of material and jot down my impressions of each piece. I end up with usually 20 or 30 short paragraphs. With this review, a lot of the paragraphs ended with "But not much air."
What that means is that it sounds to me like SVS spent most of its time, effort, and funds getting all the drivers and crossover in the Prime Tower perfectly integrated, and the box tuned to get the maximum possible performance from the dual 6.5-inch woofers. I would guess the tweeter didn't get all that much attention. It sounds very competent and clean; but, in my system and room at least, it doesn't deliver that lush treble response and huge, spacious sound that a lot of audiophiles crave. I heard this mainly in the cymbals, such as in "Jumpin' Jammies" from the Levin Brothers LP. The cymbals were there; they just didn't sound as lifelike and 3D as they do with some speakers. I noticed this issue only with music that has a lot of ambience, including some jazz records and some audiophile recordings. With pop, hip-hop, rock, and movie soundtracks, I didn't notice it.
Also, it seemed to me that there was a slight rise in the mid-treble, which didn't manifest itself as an overt coloration, only as a tendency to sound bright on a rather random selection of tunes--for example, the English Beat's "Hands Off She's Mine" and Laura Nyro's "Stoned Soul Picnic."
Comparison and Competition
When I switched back to my usual reference speakers, the $3,499/pair Revel F206, I was impressed to hear that the Prime Tower seemed to give up nothing to the F206 in dynamics and bass extension. Where the Prime Tower lost ground to the F206 was in ambience and imaging; all those stereo tricks we audiophiles love are a piece of cake for the F206, but they're not the Prime Tower's strength.
Of course, that's not a fair comparison because the F206 is 3.5 times the Prime Tower's price. Its actual competitors would include speakers like B&W's $1,099/pair 684B, which has a 6.5-inch woof and a 6.5-inch midrange; Definitive Technology's $1,199/pair BP-8020ST, which includes a built-in powered eight-inch subwoofer; NHT's $1,099/pair Absolute Tower; and PSB's $1,099/pair Imagine T, which has dual 5.25-inch woofers. I've tested the latter two, and for someone who wants more of that audiophile air'n'ambience thing, I'd probably suggest the PSB. However, the PSB can't match the Prime Tower's bass and dynamics.
For a lot of people, spending $1,000 per pair on speakers sounds crazy; but, for audiophiles, the Prime Tower is a budget speaker. Among the speakers I've heard in its price range, it probably has the most potent combination of very low sonic coloration (i.e., natural sound), impressive dynamics, and bass performance that makes a subwoofer optional. I can't say it'd be my top pick for an audiophile who wants a dazzling, enveloping soundstage, but for mainstream music listening and home theater, it's one of the best buys going.
Detailed and very useful review. I especially appreciate that you're not hiding behind mumbo-jumbo but pointing out strength and weaknesses in real-world terms, as well as not being a sound snob. Thank you!