In this review, we will be comparing PC-4000 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 PC-4000 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.
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Drivers
The efficiency of a subwoofer is directly proportional to the total radiating are squared hence the woofer quantity and diameter.Both SVS PC-4000and KEF KUBE 8b have a single woofer setup however the SVS PC-4000's woofer is 13.5-inch whereas the KEF KUBE 8b features a 8-inch woofer.
Frequency Response
PC-4000 has a frequency range of 17-200 Hz whereas KUBE 8b has a frequency range of 34-140 Hz. With a minimum frequency of 17Hz, the PC-4000 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
Cabinet Type
The SVS PC-4000 has a Bass Reflex type cabinet. Bass Reflex type subwoofers (aka Ported, Vented or Reflex Port) have enclosures that uses a port, hole or vent cut into the cabinet. Ported designs are generally more efficient than the Sealed designs. On the other hand the KEF KUBE 8b have Acoustic Suspension type enclosure. Acoustic Suspension aka Sealed type subwoofers have enclosures that are sealed hence no ports or holes exists on the cabinet. Sealed designs helps to provide more accurate and tight bass responses compared to ported designs.
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 PC-4000's and KEF KUBE 8b's external dimensions. SVS PC-4000 has external dimensions of 1194.0 x 423.0 x 423.0mm (47 x 16-5/8 x 16-5/8inch) 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 PC-4000 is clearly the larger of the two speakers. Its body is 127mm wider, 900mm taller and 84mm deeper than KEF KUBE 8b.
Below you can see the front view size comparison of SVS PC-4000 and KEF KUBE 8b in scale.
Comparison image of SVS PC-4000 and KEF KUBE 8b Size and External Dimensions
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 PC-4000 is approximately 1789.3cm2 / 277.3inch2 and base area of the KEF KUBE 8b is approximately 1003.4cm2 / 155.5inch2. The PC-4000 requires 78% 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 PC-4000 weighs 42.00kg / 92.4lbs and the KEF KUBE 8b weighs 11.36kg / 25lbs. This makes the PC-4000 270% heavier than the KUBE 8b.
Here is a comparison of how PC-4000 and KUBE 8b's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
What's in the Box of SVS PC-4000?
Here are the items that are included inside the box of PC-4000:
- Powered subwoofer
- Top-cap w/ integrated grille
- 6-feet AC power cord
- Remote control
- 4 Elastomer feet
- Owners Manual
- Important Safety Instructions
What's in the Box of KEF KUBE 8b?
Here are the items that come with the KUBE 8b:
- Powered subwoofer
- 6.5-feet AC power cord
- Speaker-level input block
- User Manual
- Important Safety Information
- Warranty Information
 Woofer Size |
13.5 inches
vs
8 inches
|
Larger woofer |
| Low Frequency Response |
17 Hz
vs
34 Hz
|
Generates deeper bass |
 High Frequency Response |
200 Hz
vs
140 Hz
|
Generates higher frequency |
 App-Based Control |
iOS,Android
vs
None
|
Control the speaker via an app |
 Height |
294mm
vs
1194mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1003cm2
vs
1789cm2
|
Takes less floor space |
 Price per pair* |
600USD
vs
2200USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
SVS PC-4000 |
KEF KUBE 8b |
| Brand |
SVS |
KEF |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
1200 watts |
300 watts |
| Frequency Response |
17-200 Hz |
34-140 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
1200-watt RMS |
300-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
13.5" |
8" |
| Woofer Composition |
Composite/Glass Fiber |
|
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
n/a |
40-140 Hz |
| Firing Direction |
bottom |
front |
Physical Specs |
|
|
| Height |
1194.0mm (47") |
294.0mm (11.6") |
| Width |
423.0mm (16.7") |
296.0mm (11.7") |
| Depth |
423.0mm (16.7") |
339.0mm (13.3") |
| Weight |
42.00kg (92.4lbs) |
11.36kg (25lbs) |
| Enclosure |
Bass Reflex |
Acoustic Suspension |
| Grille |
Yes |
n/a |
| 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 PC-4000 goes deeper - 17Hz 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 PC-4000 has the bigger amplifier - 1200W against 300W RMS, about 6dB more on tap. In a large room that is headroom before the DSP starts limiting. |
| Driver area | A | SVS PC-4000 moves more air: 13.5" against 8" is 2.85x the cone area, not the 1.69x the diameters suggest. More area means the same output with less excursion, and less distortion with it. |
| Enclosure | depends | SVS PC-4000 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. |
| Driver placement | depends | SVS PC-4000 fires down and KEF KUBE 8b fires front. A down-firing driver is more forgiving of a grille-less look and of a hard floor; a front-firing one is the safer choice on a thick carpet or a suspended timber floor. |
| Cabinet size | depends | KEF KUBE 8b is about 86% 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 PC-4000 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 $2,200, about 73% less. |
A SVS PC-4000 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 PC-4000 measures better, KEF KUBE 8b costs about 73% 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 PC-4000 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 $2,200 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.