In this review, we will be comparing KUBE 8b and SUB3070, two Powered Subwoofer speakers from KEF and ELAC. 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 KEF KUBE 8b and ELAC SUB3070 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 KEF KUBE 8band ELAC SUB3070 have a single woofer setup however the KEF KUBE 8b's woofer is 8-inch whereas the ELAC SUB3070 features a 12-inch woofer.
Frequency Response
KUBE 8b has a frequency range of 34-140 Hz whereas SUB3070 has a frequency range of 18-180 Hz. With a minimum frequency of 18Hz, the SUB3070 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
Both KEF KUBE 8b and ELAC SUB3070 have Acoustic Suspension type cabinets. 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 KEF KUBE 8b's and ELAC SUB3070's external dimensions. 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) whereas ELAC SUB3070 has external dimensions of 435.0 x 520.0 x 477.0mm (17-1/8 x 20-7/16 x 18-3/4inch).
ELAC SUB3070 is clearly the larger of the two speakers. Its body is 224mm wider, 141mm taller and 138mm deeper than KEF KUBE 8b.
Size, drawn to scale
Both speakers 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 surface and pushed back to the same wall, so the deeper one visibly sticks out further.
ELAC SUB3070 needs about 147% more floor or shelf area. ELAC SUB3070 is 138mm deeper, so it stands that much further out from the wall. ELAC SUB3070 is 141mm taller.
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 KEF KUBE 8b is approximately 1003.4cm2 / 155.5inch2 and base area of the ELAC SUB3070 is approximately 2480.4cm2 / 384.5inch2. The KUBE 8b requires 60% less surface area than the SUB3070 which gives it a small advantage 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 KEF KUBE 8b weighs 11.36kg / 25lbs and the ELAC SUB3070 weighs 35.00kg / 77lbs. This makes the SUB3070 208% heavier than the KUBE 8b.
Here is a comparison of how KUBE 8b and SUB3070's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
What's in the Box of KEF KUBE 8b?
Here are the items that are included inside the box of KUBE 8b:
- Powered subwoofer
- 6.5-feet AC power cord
- Speaker-level input block
- User Manual
- Important Safety Information
- Warranty Information
What's in the Box of ELAC SUB3070?
Here are the items that come with the SUB3070:
- Powered subwoofer
- AC power cord
- 2 Steel bottom plates
- 4 Spikes
- 4 Locking-knobs
- 4 Protective discs
- Operating Instructions
 Height |
294mm
vs
435mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1003cm2
vs
2480cm2
|
Takes less floor space |
 Price per pair* |
600USD
vs
999USD
|
costs less (*prices may change depending on the seller, location and time) |
 Woofer Size |
12 inches
vs
8 inches
|
Larger woofer |
| Low Frequency Response |
18 Hz
vs
34 Hz
|
Generates deeper bass |
 High Frequency Response |
180 Hz
vs
140 Hz
|
Generates higher frequency |
 Wireless Operation |
Yes
vs
No
|
Connect your subwoofer to your system wireless |
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.
ELAC SUB3070 needs about 147% more floor area. ELAC SUB3070 stands 138mm further into the room. ELAC SUB3070 is 141mm taller.
| General |
KEF KUBE 8b |
ELAC SUB3070 |
| Brand |
KEF |
ELAC |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
300 watts |
1200 watts |
| Frequency Response |
34-140 Hz |
18-180 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
300-watt RMS |
1200-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
8" |
12" |
| Woofer Composition |
|
Aluminum |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
40-140 Hz |
n/a |
| Firing Direction |
front |
side |
Physical Specs |
|
|
| Height |
294.0mm (11.6") |
435.0mm (17.1") |
| Width |
296.0mm (11.7") |
520.0mm (20.5") |
| Depth |
339.0mm (13.3") |
477.0mm (18.8") |
| Weight |
11.36kg (25lbs) |
35.00kg (77lbs) |
| Enclosure |
Acoustic Suspension |
Acoustic Suspension |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
2 Years |
1 Year |
| Labor Warranty |
2 Years |
1 Year |
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 | ELAC SUB3070 goes deeper - 18Hz against 34Hz. Under 20Hz is felt more than heard - the bottom of a pipe organ and the bottom of a film mix. |
| Amplifier power | B | ELAC SUB3070 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 | B | ELAC SUB3070 moves more air: 12" against 8" is 2.25x the cone area, not the 1.5x 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. |
| Speaker-level inputs | B | ELAC SUB3070 takes a speaker-level connection as well as line level. That is what lets it work with an integrated amplifier or a vintage receiver that has no subwoofer output at all. |
| Wireless option | depends | Only ELAC SUB3070 offers a wireless link. It decides where the sub can go if you cannot run a cable, and is worth nothing if you can. |
| Driver placement | depends | KEF KUBE 8b fires front and ELAC SUB3070 fires side. 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 73% 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 | KEF KUBE 8b carries 2 years on parts against 1 years. A subwoofer amplifier works harder than anything else in the system, so this is not a throwaway line. |
| Price | A | KEF KUBE 8b costs less - $600 against $999, about 40% less. |
A KEF KUBE 8b B ELAC SUB3070
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: ELAC SUB3070 measures better, KEF KUBE 8b costs about 40% less. In a normal room, placement will make a bigger difference than the gap between these two. Check your amplifier first: if it has no subwoofer or preamp output, ELAC SUB3070 is the only one of these two you can connect at all. 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 $999 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.