SVS Prime Tower Review

SVS Prime Tower: $499.99 each



by Wayne Myers


Introduction

The SVS Prime Tower was introduced at Rocky Mountain Audio Fest in October. At $1000 per pair, the Prime Tower has a lot of competition in its class, speakers that are trying to sound like their more expensive bigger brothers. Some come close but most have flaws which hold them back, as is to be expected. A few really shine, seeming to break any rules about how much a speaker should cost to sound really good.

I got a good introduction to the Prime Towers at RMAF, resisting the impulse to move them around to optimize their setup, and asked for a pair to review in detail. The Prime Towers stood in the shadow of the SVS Ultra Towers, which I have heard several times and which, at $2,000 per pair, perform very well and leave big shoes for the Prime Towers to fill. The Ultra Tower also shows that the SVS engineers are able to make speakers that perform very well and give listeners a lot of value for their dollar.


Description

The Prime Tower is a three-way bass reflex design with dual rear-firing ports. Drivers include two 6.5-inch woofers and a 4.5-inch midrange, all with polypropylene cones and cast ABS-fiberglass composite baskets, and a one-inch aluminum dome tweeter with diffuser. The two woofers cross over to the midrange at different frequencies - 165 Hz and 350 Hz - with different slopes, and the midrange and tweeter cross over at 2.1 kHz. The mid/tweeter crossover was especially well executed, invisible on measurement plots and smoothly integrated even at different listening angles. The available finishes are piano black or black ash. I received the piano black, which was expertly done.

The Prime Towers are compact, versatile, and VERY easy to place.

SVS Website.


Specifications

Associated Review Equipment

Measurements

Frequency response measured outdoors at 2 m on the tweeter axis.




In-room response at the Listening Position on the tweeter axis, zero listening angle. Mids and higs are unusually flat.




Total Harmonic Distortion at 75 dB SPL is well below 1% through the listening range.




Total Harmonic Distortion at 85 dB SPL is below 1% above 100 Hz.




Total Harmonic Distortion at 95 dB SPL has a distortion peak of 3% at 250 Hz for the speaker shown. It was 1.4% for the other speaker. Above 100 Hz most of the listening range is still below 1% distortion, except at 3 kHz where it peaks slightly above.




IM Distortion (DIN)
L @ 75 dB SPL = 0.66%
R @ 75 dB SPL = 0.37%
L @ 85 dB SPL = 0.84%
R @ 85 dB SPL = 0.48%
L @ 95 dB SPL = 1.4%
R @ 95 dB SPL = 1.0%


Impulse response. The pre-ringing indicates near-perfect brick-wall low-pass filtering in the Roland audio interface with high-frequency content approaching that filter limit. The jagged peaks as the impulse returns to zero and the jagged overshoot beyond might account for some of the lack of transparency noticed in listening tests. They appeared on indoor and reflection-free outdoor measurements.




Step response. Low-frequency ringing is pronounced and indicates less-than-ideal control of the woofers. I cannot say that this stood out in a way that concerned me - while bass dynamics were not super-tight, they never seemed muddy or mushy. The initial high-frequency "bounce" and the jagged areas in the first 20 mS indicate mid and high frequencies where clarity was somewhat less than desired. These step-response waveform features were present on indoor and reflection-free outdoor measurements.




Group Delay has peaks at 170 Hz and 310 Hz related to the crossover network. Phase shift is quite non-linear through this region. But tight component tolerances keep these curves almost perfectly overlaid between left and right speakers and soundstage and imaging performance are unaffected.




Impedance measurements again show very tight tolerances. The impedance curves are almost perfectly overlaid.




Polar Response measurements, taken indoors, gated, with 8 ms gate, normalized. Microphone was stationary, speaker was turned in 5 degree increments.




Initial Listening Test

The Prime Towers put their best foot forward quickly by performing a very thorough disappearing act in the first location where I set them up. They were a little close together, and I set with no toe-in. They sounded much bigger than their size, and projected quite an engaging soundstage regardless of the disadvantaged of their positioning. For my first listening session I left them right where they were.

At RMAF, I had noticed that one of the main differences between the Prime and Ultra Towers was the smoothness and transparency of the tweeter frequency range. The Ultra Tower tweeter sounded better each of the first three times I heard the Ultras over a six-month period, and I suspect that the engineers were refining its design along the way. Choosing to focus on high-frequency performance for a bit, I added a shelf filter with a gradual 5 dB rise starting at 2 kHz. The overly bright presentation was intended to emphasize any flaws or annoyances in the high-frequency range.

The first listening session made use of the Eels album Blinking Lights and Revelations from beginning to end, some songs repeated. Mark Oliver Everett's gravelly voice managed to trigger a couple of peaks in the upper range, but for the most part the Prime Towers were very listenable even with that range boost. They did a nice job of reaching into inner detail of the voice and instruments, and were quite clear and smooth overall.

On Trouble With Dreams, with sampled glockenspiel, the soundstage came alive with high, clear bells, a delightful surprise that was one of the highlights of my working with the Prime Towers.

The rest of the frequency range was managed very well in this setup, too. Drums and percussion sounds were tight and lively. Vocals and string instruments were accurate natural sound. Imaging was very sharp and specific.


Listening Angle Tests

Curious about how easily the Prime Towers were to place, I lined them up more carefully and spent time with them playing on-axis (zero-degree listening angle) and angled outward in 5-degree increments out to 30 degrees. The first and biggest impression was with how consistent the soundstage and imaging (SS&I) through these angles. Most speakers I have worked with in the class had a definite sweet angle or two where imaging locked in, and imaged poorly at any other angle. The Prime Towers defied all attempts to find an angle where the soundstage and image clarity were less than exceptional, and insisted on remaining invisible throughout the exercise, thoroughly disappearing wherever placed. I will mention that they had the advantage of a blank wall behind them, my ideal for soundstage development and imaging.

As the listening angle test proceeded, the soundstage opened more and more with each outward turn of the speakers. Imaging remained very sharp, softening slightly at the wider angles but only to a barely noticeable degree. This set of characteristics alone moved the Prime Towers for me into a class with few equals at anywhere near the price, a thoroughly impressive performance. I can think of competing speakers that I rejoiced with at finally finding a narrow sweet angle with adequate (SS&I) for an enjoyable listening experience. A pair of towers allowing so much flexibility and delivering first-rate spacial performance is really quite a gem. Expecting the new SVS family offering to be solid, I am really knocked out by what they delivered.

The upper-mid and high-frequency response seemed to smooth somewhat, with a few minor on-axis peaks that evened out with the widening angle. Overall frequency response was very consistent through those same angles. While far from ruler-flat, the range is free of annoying spikes and very listenable. One wish I had was that the 2.5 kHz presence peak at the bottom of the tweeter's range could be a decibel lower, softened just a bit. I verified this by temporarily applying a single parametric band filter with 1 dB of loss centered on the octave, and the result was just right.

B-52s, Revolution Earth - mono mix, Good Stuff, Vision Of A Kiss:
The mono mix of Revolution Earth is a good image sharpness test. With speakers that image poorly, it will sound stereo due to amplitude and time mismatching between the left and right sources. With tight imaging, the song is razor-blade narrow. With the Prime Towers, the song was sharp and stable. On the other B-52s tracks, a strummed acoustic guitar was punchy and focused, but depth acuity was lacking, the final quality of a soundstage which requires acoustical enhancement, which sometimes occurs by happenstance but usually requires some work. Bass lines and kick drum were solid, not super deep.

Eels, Baby Loves Me, Spectacular Girl:
Solid bass

Beth Nielsen Chapman, Beyond The Blue:
The deepest drums did not have the depth I remember. This is to be expected. Bass depth and maximum volume level are the main gains generally to be found as speaker prices go above $1000 per pair.

Radiohead, Weird Fishes, All I Need, The National Anthem:
The lead-in drumstick clicks were sharply focused. Glockenspiel samples also were precisely located and very clear. The dense jazz band did not distort or become congested.

Deerhoof, Fete d'Adieu:
A dense track, handled with ease, no sense of strain at high volume.

Porcupine Tree, Shallow, Way Out Of Here:
Heavy tracks, punchy snare drum that threatens to clip on every strike, dense metal guitars, all stayed clean and uncongested.

New Pornographers, Brill Bruisers, Fantasy Fools, Dancehall Domine, From Blown Speakers:
These tracks were mixed with a lot of midrange information. Here the Prime Towers were slightly lacking in transparency.

Michael Hedges, Eleven Small Roaches:
Nice definition, not super detailed on string plucks, but true tonality.


Other Observations

While SS&I performance from the SVS Prime Towers was exceptional, there was a slight lack of clarity that was not explained by distortion measurements, as though the music had a touch of graininess to it. This effect was minor but occasionally apparent at mid frequencies, especially on tracks with dense content in that range. When comparing the Prime Towers to an inexpensive speaker with a folded-motion tweeter, the difference in transparency was noticeable. While not a major issue, it did get my attention occasionally and must be mentioned. I doubt it would ever turn up in home theater use, and many of the music tracks I listened to did not suffer from it, but dense vocal harmonies like the New Pornographers tracks became slightly hashy from the effect. The inner detail on the Michael Hedges acoustic guitar track was also affected.


Conclusions

The SVS Ultra Towers were a pleasant surprise. I was expecting a solid, somewhat utilitarian speaker that handled home theater and music tracks like a trooper, performing adequately but without finesse. But the SVS team has shown us that they intend to be thought of as serious loudspeaker makers. There is no doubt the Prime Towers are on a short list of models that should be considered by anyone with $1000 to spend on a pair of speakers.

I have emphasized two-channel application because of the (SS&I) performance, but SVS's per-speaker pricing indicates that they also aim for home theater front-mains business for the Prime Towers. Broad dispersion makes the compact towers simple as pie to place in a wide home theater with three- or four-wide seating. Anyone with a budget of around $500 per speaker for0 towers should look closely at the SVS Prime Towers. They do too many things right to be ignored.