In this review, we will be comparing SB17 Ultra R Evolution and KF92, two Powered Subwoofer speakers from SVS and KEF. Being Powered subwoofers, they both have built-in amplifiers so you don't need an external power amp or an integrated amp to power them. Let's have a brief look at the main features of SVS SB17 Ultra R Evolution and KEF KF92 first before getting into our more detailed comparison.
The sections below take each area in turn: driver and amplifier, frequency response, physical size and connectivity.
Drivers
The efficiency of a subwoofer is directly proportional to the total radiating are squared hence the woofer quantity and diameter.SVS SB17 Ultra R Evolution and KEF KF92 have a totally different setup: the SVS SB17 Ultra R Evolution features 1 x 17-inch drivers whereas the KF92 features 2 x 9-inch drivers.
Frequency Response
SB17 Ultra R Evolution has a frequency range of 15-320 Hz whereas KF92 has a frequency range of 11-200 Hz. With a minimum frequency of 11Hz, the KF92 can go slightly deeper then the SB17 Ultra R Evolution's min frequency of 15Hz.
Below graphs depict how these two speakers compare with the max, min and average values of the Min and Max Frequencies of other speakers in the Subwoofer class in our database.
Low Frequency
Subwoofer Speakers
SVS SB17 Ultra R Evolution
High Frequency
Subwoofer Speakers
SVS SB17 Ultra R Evolution
Physical Specs
The size of a speaker can sometimes be an important decision factor due to space constraints or in some cases purely for esthetic reasons. In this section, we are going to compare SVS SB17 Ultra R Evolution's and KEF KF92's external dimensions. SVS SB17 Ultra R Evolution has external dimensions of 508.0 x 495.3 x 539.8mm () whereas KEF KF92 has external dimensions of 353.0 x 331.0 x 362.0mm (13-7/8 x 13 x 14-1/4inch).
SVS SB17 Ultra R Evolution is clearly the larger of the two speakers. Its body is 164.3mm wider, 155mm taller and 177.8mm deeper than KEF KF92.
Base Surface Area Comparison
Base surface area of a loudspeaker may become a determining factor when the space in your room or desk is limited.
The base surface area of the SVS SB17 Ultra R Evolution is approximately 2673.6cm2 / 414.4inch2 and base area of the KEF KF92 is approximately 1198.2cm2 / 185.7inch2. The SB17 Ultra R Evolution requires 123% more surface area than the KF92 which gives it a small disadvantage on placement in tight spaces.
Weight Comparison The weight of a subwoofer may become an important factor if you need to move and reposition the unit often to find the optimal positioning, also known as 'Subwoofer Crawling'. The SVS SB17 Ultra R Evolution weighs 56.25kg / 123.8lbs and the KEF KF92 weighs 20.05kg / 44.1lbs. This makes the SB17 Ultra R Evolution 181% heavier than the KF92.
Here is a comparison of how SB17 Ultra R Evolution and KF92's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
SVS SB17 Ultra R Evolution
 Woofer Size |
17 inches
vs
9 inches
|
Larger woofer |
 High Frequency Response |
320 Hz
vs
200 Hz
|
Generates higher frequency |
| Number of Woofers |
2
vs
1
|
More woofers |
| Low Frequency Response |
11 Hz
vs
15 Hz
|
Generates deeper bass |
 Height |
353mm
vs
508mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1198cm2
vs
2673cm2
|
Takes less floor space |
 Price per pair* |
2000USD
vs
2700USD
|
costs less (*prices may change depending on the seller, location and time) |
Size, drawn to scale
Both subwoofers and both views share one scale, so everything here is directly comparable. Hover a box for its dimensions.
One scale for both, standing on the same floor and pushed back to the same wall, so the bigger one visibly takes more of the room.
SVS SB17 Ultra R Evolution needs about 123% more floor area. SVS SB17 Ultra R Evolution stands 178mm further into the room. SVS SB17 Ultra R Evolution is 155mm taller.
| General |
SVS SB17 Ultra R Evolution |
KEF KF92 |
| Brand |
SVS |
KEF |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Frequency Response |
15-320 Hz |
11-200 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
2800-watt RMS |
1000-watt RMS |
| Watts Peak (Max) |
6000-watt RMS |
n/a |
Drivers |
|
|
| Woofer Quantity |
1 |
2 |
| Woofer Size |
17" |
9" |
| Woofer Composition |
|
Hybrid aluminum |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
Physical Specs |
|
|
| Height |
508.0mm (20") |
353.0mm (13.9") |
| Width |
495.3mm (19.5") |
331.0mm (13") |
| Depth |
539.8mm (21.3") |
362.0mm (14.3") |
| Weight |
56.25kg (123.8lbs) |
20.05kg (44.1lbs) |
| Enclosure |
|
Acoustic Suspension |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
5 Years |
2 Years |
| Labor Warranty |
5 Years |
2 Years |
Two quite different sizes of subwoofer. Room volume decides this more than anything else on the page: a big driver in a small room is wasted, and a small one in a large room is worked to death.
| Area | Better | Why |
|---|
| Bass depth | B | KEF KF92 goes deeper - 11Hz against 15Hz. Under 20Hz is felt more than heard - the bottom of a pipe organ and the bottom of a film mix. |
| Amplifier power | A | SVS SB17 Ultra R Evolution has the bigger amplifier - 2800W against 1000W RMS, about 4.5dB more on tap. In a large room that is headroom before the DSP starts limiting. |
| Driver area | A | SVS SB17 Ultra R Evolution moves more air: 17" against 2 x 9" is 1.78x the cone area, not the 1.34x the diameters suggest. More area means the same output with less excursion, and less distortion with it. |
| Enclosure | evenly matched | Both are sealed designs, so they roll off in much the same way. |
| Cabinet size | depends | KEF KF92 is about 69% smaller by volume. In a subwoofer that is a real trade rather than a preference: box volume is how you get output low down without a bigger amplifier. |
| Warranty | A | SVS SB17 Ultra R Evolution carries 5 years on parts against 2 years. A subwoofer amplifier works harder than anything else in the system, so this is not a throwaway line. |
| Price | B | KEF KF92 costs less - $2,000 against $2,700, about 26% less. |
A SVS SB17 Ultra R Evolution B KEF KF92
depends neither is better in the abstract - it turns on your room, your system or how you will use them. Only specs published for both subwoofers are judged; anything missing on either side is left out rather than guessed.
Which should you choose?
The usual trade-off: SVS SB17 Ultra R Evolution measures better, KEF KF92 costs about 26% less. In a normal room, placement will make a bigger difference than the gap between these two. If placement is the constraint - a corner, behind a sofa, under a desk - KEF KF92 is the one that will actually go there, and a well-placed small subwoofer beats a badly-placed big one every time.
One thing outweighs everything above: where the subwoofer stands. Room modes can add or remove 10dB or more at a given seat, which is far larger than any difference on this page. Before spending more, try the sub in two or three positions - the crawl test, where you put it in the listening seat and crawl the room to find where the bass sounds best, costs nothing and usually beats an upgrade.