In this review, we will be comparing SA-CS9 and KUBE 8b, two Powered Subwoofer speakers from Sony 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 Sony SA-CS9 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 Sony SA-CS9and KEF KUBE 8b have a single woofer setup however the Sony SA-CS9's woofer is 10-inch whereas the KEF KUBE 8b features a 8-inch woofer.
Frequency Response
SA-CS9 has a frequency range of 28-200 Hz whereas KUBE 8b has a frequency range of 34-140 Hz. With a minimum frequency of 28Hz, the SA-CS9 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 Sony SA-CS9 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 Sony SA-CS9's and KEF KUBE 8b's external dimensions. Sony SA-CS9 has external dimensions of 345.0 x 295.0 x 400.0mm (11.6 x 13.6 x 15.7 inch) 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).
KEF KUBE 8b is 51mm shorter and 61mm less deeper than Sony SA-CS9 but it is also 1mm wider.
Below you can see the front view size comparison of Sony SA-CS9 and KEF KUBE 8b in scale.
Comparison image of Sony SA-CS9 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 Sony SA-CS9 is approximately 1180.0cm2 / 182.9inch2 and base area of the KEF KUBE 8b is approximately 1003.4cm2 / 155.5inch2. The SA-CS9 requires 18% 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 Sony SA-CS9 weighs 11.50kg / 25.3lbs and the KEF KUBE 8b weighs 11.36kg / 25lbs. This makes the SA-CS9 1% heavier than the KUBE 8b.
Here is a comparison of how SA-CS9 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 Sony SA-CS9?
Here are the items that are included inside the box of SA-CS9:
- Sony SA-CS9 10-inch 115W Subwoofer
- 6.5-feet Phono Cord
- 4 x Foot Pads
- Grille
- Limited 90-Day Manufacturer Warranty
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 |
10 inches
vs
8 inches
|
Larger woofer |
| Low Frequency Response |
28 Hz
vs
34 Hz
|
Generates deeper bass |
 High Frequency Response |
200 Hz
vs
140 Hz
|
Generates higher frequency |
 Price per pair* |
248USD
vs
600USD
|
costs less (*prices may change depending on the seller, location and time) |
 Height |
294mm
vs
345mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1003cm2
vs
1180cm2
|
Takes less floor space |
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.
Sony SA-CS9 needs about 18% more floor area. Sony SA-CS9 stands 61mm further into the room. Sony SA-CS9 is 51mm taller.
| General |
Sony SA-CS9 |
KEF KUBE 8b |
| Brand |
Sony |
KEF |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
115 watts |
300 watts |
| Frequency Response |
28-200 Hz |
34-140 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
115-watt RMS |
300-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
10" |
8" |
| Woofer Composition |
foamed-mica cellular reinforced |
|
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
n/a |
40-140 Hz |
| Firing Direction |
front |
front |
Physical Specs |
|
|
| Height |
345.0mm (13.6") |
294.0mm (11.6") |
| Width |
295.0mm (11.6") |
296.0mm (11.7") |
| Depth |
400.0mm (15.7") |
339.0mm (13.3") |
| Weight |
11.50kg (25.3lbs) |
11.36kg (25lbs) |
| Enclosure |
Bass Reflex |
Acoustic Suspension |
| Available Colors |
Black |
n/a |
| Grille |
Yes |
n/a |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
|
2 Years |
| Labor Warranty |
|
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 | Sony SA-CS9 goes deeper - 28Hz against 34Hz. A real difference, though most music has little content below 34Hz. |
| Amplifier power | B | KEF KUBE 8b has the bigger amplifier - 300W against 115W RMS, about 4.2dB more on tap. In a large room that is headroom before the DSP starts limiting. |
| Driver area | A | Sony SA-CS9 moves more air: 10" against 8" is 1.56x the cone area, not the 1.25x the diameters suggest. More area means the same output with less excursion, and less distortion with it. |
| Enclosure | depends | Sony SA-CS9 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 28% 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. |
| Price | A | Sony SA-CS9 costs less - $248 against $600, about 59% less. |
A Sony SA-CS9 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?
Sony SA-CS9 has the edge on paper, though not by much. The "depends" rows are more likely to decide this than the score is. Films or music? If this is mainly a home cinema, Sony SA-CS9 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 $248 each, two Sony SA-CS9 cost about $496 against $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.