SVS, a well-known name in the subwoofer world, has long offered a range of options, from their budget-friendly 1000 Series to the powerful Ultra lineup. For the past eight years, their 16-Ultra series stood as their flagship, leading many to anticipate its successor. Instead of a simple upgrade, SVS has completely redesigned their top-tier offering with the introduction of the 17-Ultra R|Evolution series, featuring both ported (PB17-Ultra) and sealed (SB17-Ultra) models.
For those unfamiliar, ported subwoofers are often the preferred choice for home theaters due to their ability to reach deeper bass frequencies and deliver significant impact. However, they tend to be larger and can sometimes produce unwanted "chuffing" sounds at high volumes. Sealed subwoofers, on the other hand, are more compact and generally offer tighter, more controlled bass. Many find them easier to integrate with room equalization. While they save space, they typically don't extend as low in the frequency range as their ported counterparts.
This brings us to the SB17-Ultra. Sealed subwoofers have traditionally involved a trade-off, particularly in deep bass extension. But could the SB17-Ultra be the exception?
Under the Hood
The SB17-Ultra is a completely new design, starting with its 17-inch driver featuring a dual 8-inch voice coil, which SVS claims enhances driver control. Notably, these are some of the largest voice coils found in subwoofers, typically ranging from 3 to 5 inches. A larger voice coil allows for more precise driver movement, resulting in improved accuracy and control. The new driver also boasts a substantial 48.9mm Xmax and an 81.78mm Xmech excursion, allowing for nearly two inches of peak-to-peak cone movement.
Powering the SB17-Ultra is a brand-new dual-mono Class D amplifier delivering a total of 2,800 watts. Unlike conventional designs, this amplifier has separate output sections for each of the driver's voice coils. The power supply has also been upgraded to a Switch Mode Power Supply (SMPS) with active Power Factor Correction (PFC). This ensures a stable 160V for the amplifier, regardless of voltage fluctuations (100V-240V), even on a standard 15-amp circuit.
Managing all this power and performance is a new 295MHz DSP from Analog Devices, featuring double-precision 56-bit filtering. SVS states this is five times faster than previous iterations. This DSP manages all amplifier functions and allows for complete customization via the SVS smartphone app.
Design and Build
The SB17-Ultra boasts the robust design expected from an SVS flagship subwoofer. The cabinet is constructed from dense MDF with internal bracing to minimize unwanted vibrations. SVS's Iso-Elastomer feet further help isolate the subwoofer from the floor.
There's no getting around it—the SB17-Ultra is a substantial subwoofer, measuring 20 inches tall, 19.5 inches wide, and 21.2 inches deep, weighing in at a hefty 124 pounds. It's available in two finishes: Piano Gloss Black and Black Oak Real Wood Veneer. The review unit arrived in Piano Gloss Black, which offers a premium aesthetic, though the Black Oak option might be preferable for dedicated home theaters where reflections are a concern.
A notable change from the 16-Ultra series is the grille. The previously used metal grille, which received mixed feedback, has been replaced with a fabric mesh grille that easily snaps onto the front. This change is likely to be welcomed by many SVS enthusiasts who preferred the look and feel of their earlier fabric grilles.
On the rear panel, the SB17-Ultra includes RCA and XLR inputs and outputs, along with a dedicated LFE RCA input. It also features a 3.5mm input for home automation systems and a trigger input compatible with 3 to 12V signals. For placement flexibility, it's also compatible with SVS's SoundPath wireless adapter.
SVS has also incorporated a new OLED display with navigation buttons on the back of the unit. Unlike the front-mounted display on the SB16, this rear placement is convenient for initial setup, but everyday adjustments will likely be handled through the comprehensive SVS smartphone app.
Setup and Calibration
Setting up the SB17-Ultra is relatively simple, though fine-tuning requires more effort. The new Room Correction software is still in development, with a separate review planned upon its release.
The SVS app provides extensive control over the subwoofer's settings, including volume, a fully adjustable low-pass filter, phase and polarity adjustments, a six-band parametric EQ, room gain compensation, tuning modes, and power management options. It also offers three memory presets—Music, Movies, and Custom—for quick switching between listening preferences. For the review setup, the SB17-Ultra was placed in the front left corner of the listening room, the optimal position for that space.
Performance in Action
The SB17-Ultra delivers impressive performance, exceeding expectations for a sealed subwoofer. In the listening room, it effortlessly reached down to 15Hz at 85dB, a surprising feat for a sealed design. Despite its size, the bass remained remarkably controlled, offering the accuracy typically associated with sealed subs while delivering the deep, room-filling impact usually found in ported models.
When listening to music, the 17-inch driver proved its capabilities. In Mike Candys & Le Shuuk’s "Something Like That," the SB17-Ultra delivered a powerful chest-thumping kick with each bass hit, adding significant energy to the track. The subwoofer maintained tight control over the song's rolling bassline, handling deep, pulsing synths and an energetic drop without losing definition or muddying the mid frequencies.
While sealed subwoofers often excel with music but can struggle with the low-frequency demands of movies, the SB17-Ultra proved to be an exception, even for someone who typically prefers ported designs for film. The subwoofer exhibited serious output capabilities. During scenes with deep, sustained bass in "Underwater," a movie known to challenge sealed subs, the SB17-Ultra not only started and stopped with precision but also pressurized the room, a rare characteristic for a sealed design.
In the lightcycle battle from "Tron: Legacy," the impact of each glowing trail was palpable. Crashes and explosions carried significant weight across the soundstage. Notably, the mid-bass presence in the 40-70Hz range was particularly impressive, adding a punch that had been previously unnoticed with other subwoofers. This highlighted a mid-bass energy that complemented the deep low-end extension.
While the SB17-Ultra comes surprisingly close to the low-end extension of a ported subwoofer, it doesn't entirely replace it. The PB17-Ultra likely offers even more in that regard. However, for a sealed design, the SB17-Ultra performs exceptionally well. Even when pushed hard, it remained composed, handling demanding content like the opening of "Edge of Tomorrow" with ease.
Final Thoughts
The SVS SB17-Ultra handled everything thrown its way, from music to movies, without any signs of strain. While it doesn't perfectly match the deep-end extension of a ported subwoofer, it comes remarkably close, making the trade-offs minimal, especially when space is a consideration. A pair of these in a decent-sized room would likely leave very little to be desired. Few sealed subwoofers can deliver this level of power and control. Combined with the upcoming auto EQ and the comprehensive app-based adjustments, the SVS SB17-Ultra is a compelling option, earning an AVSForum Top Choice for 2025 and potentially changing the preferences of even long-time ported subwoofer enthusiasts.
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