In this review, we will be comparing PB 5000 R Evolution and KUBE 8b, 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 PB 5000 R Evolution and KEF KUBE 8b 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.Both SVS PB 5000 R Evolutionand KEF KUBE 8b have a single woofer setup however the SVS PB 5000 R Evolution's woofer is 15-inch whereas the KEF KUBE 8b features a 8-inch woofer.
Frequency Response
PB 5000 R Evolution has a frequency range of 13-180 Hz whereas KUBE 8b has a frequency range of 34-140 Hz. With a minimum frequency of 13Hz, the PB 5000 R Evolution can go significantly deeper on the low side and provide stronger bass compared to the KUBE 8b's min frequency of 34Hz.
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
High Frequency
Subwoofer Speakers
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 PB 5000 R Evolution's and KEF KUBE 8b's external dimensions. SVS PB 5000 R Evolution has external dimensions of 595.3 x 520.7 x 730.3mm () whereas KEF KUBE 8b has external dimensions of 294.0 x 296.0 x 339.0mm (11-9/16 x 11-5/8 x 13-5/16inch).
SVS PB 5000 R Evolution is clearly the larger of the two speakers. Its body is 224.7mm wider, 301.3mm taller and 391.3mm deeper than KEF KUBE 8b.
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 PB 5000 R Evolution is approximately 3802.7cm2 / 589.4inch2 and base area of the KEF KUBE 8b is approximately 1003.4cm2 / 155.5inch2. The PB 5000 R Evolution requires 279% more surface area than the KUBE 8b 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 PB 5000 R Evolution weighs 69.81kg / 153.6lbs and the KEF KUBE 8b weighs 11.36kg / 25lbs. This makes the PB 5000 R Evolution 515% heavier than the KUBE 8b.
Here is a comparison of how PB 5000 R Evolution and KUBE 8b's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
 Woofer Size |
15 inches
vs
8 inches
|
Larger woofer |
| Low Frequency Response |
13 Hz
vs
34 Hz
|
Generates deeper bass |
 High Frequency Response |
180 Hz
vs
140 Hz
|
Generates higher frequency |
 Height |
294mm
vs
595mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1003cm2
vs
3802cm2
|
Takes less floor space |
 Price per pair* |
600USD
vs
2600USD
|
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 PB 5000 R Evolution needs about 279% more floor area. SVS PB 5000 R Evolution stands 391mm further into the room. SVS PB 5000 R Evolution is 301mm taller.
| General |
SVS PB 5000 R Evolution |
KEF KUBE 8b |
| Brand |
SVS |
KEF |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Frequency Response |
13-180 Hz |
34-140 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
2000-watt RMS |
300-watt RMS |
| Watts Peak (Max) |
5000-watt RMS |
n/a |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
15" |
8" |
| Woofer Composition |
|
|
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
n/a |
40-140 Hz |
| Firing Direction |
n/a |
front |
Physical Specs |
|
|
| Height |
595.3mm (23.4") |
294.0mm (11.6") |
| Width |
520.7mm (20.5") |
296.0mm (11.7") |
| Depth |
730.3mm (28.8") |
339.0mm (13.3") |
| Weight |
69.81kg (153.6lbs) |
11.36kg (25lbs) |
| Enclosure |
|
Acoustic Suspension |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
5 Years |
2 Years |
| Labor Warranty |
5 Years |
2 Years |
A ported subwoofer against a sealed one. That is the most consequential line on this page: it decides how the bass rolls off, how it behaves in a small room, and how much output you get for the size of the box.
| Area | Better | Why |
|---|
| Bass depth | A | SVS PB 5000 R Evolution goes deeper - 13Hz against 34Hz. Under 20Hz is felt more than heard - the bottom of a pipe organ and the bottom of a film mix. |
| Amplifier power | A | SVS PB 5000 R Evolution has the bigger amplifier - 2000W against 300W RMS, about 8.2dB more on tap. In a large room that is headroom before the DSP starts limiting. |
| Driver area | A | SVS PB 5000 R Evolution moves more air: 15" against 8" is 3.52x the cone area, not the 1.88x the diameters suggest. More area means the same output with less excursion, and less distortion with it. |
| Enclosure | depends | SVS PB 5000 R Evolution is ported - a ported box gives more output low down for its size, at the cost of a steeper roll-off below tuning; KEF KUBE 8b is sealed - a sealed box rolls off gently and is usually the easier one to integrate in a small or awkward room. Neither is better in the abstract; ported tends to suit films and sealed tends to suit music, and both generalisations have exceptions. |
| Cabinet size | depends | KEF KUBE 8b is about 87% 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 PB 5000 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 KUBE 8b costs less - $600 against $2,600, about 77% less. |
A SVS PB 5000 R Evolution B KEF KUBE 8b
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 PB 5000 R Evolution measures better, KEF KUBE 8b costs about 77% less. In a normal room, placement will make a bigger difference than the gap between these two. Films or music? If this is mainly a home cinema, SVS PB 5000 R Evolution will hit harder for the money; if it is mainly for music in a normal-sized room, KEF KUBE 8b is usually the easier one to make sound right. Two small subwoofers beat one big one in most rooms - a pair evens out the room modes in a way no single box can, whatever its specs. At $600 each, two KEF KUBE 8b cost about $1,200 against $2,600 for one of the other, which is worth a thought.
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.