In this review, we will be comparing Depth 215 and KUBE 10b, two Powered Subwoofer speakers from MartinLogan 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 MartinLogan Depth 215 and KEF KUBE 10b 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.MartinLogan Depth 215 and KEF KUBE 10b have a totally different setup: the MartinLogan Depth 215 features 2 x 15-inch drivers whereas the KUBE 10b features 1 x 10-inch drivers.
Frequency Response
Depth 215 has a frequency range of 18-120 Hz whereas KUBE 10b has a frequency range of 24-140 Hz. With a minimum frequency of 18Hz, the Depth 215 can go significantly deeper on the low side and provide stronger bass compared to the KUBE 10b's min frequency of 24Hz.
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 MartinLogan Depth 215 and KEF KUBE 10b 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 MartinLogan Depth 215's and KEF KUBE 10b's external dimensions. MartinLogan Depth 215 has external dimensions of 572.0 x 580.0 x 595.0mm (22-1/2 x 22-13/16 x 23-7/16inch) whereas KEF KUBE 10b has external dimensions of 372.0 x 356.0 x 397.0mm (14-5/8 x 14 x 15-5/8inch).
MartinLogan Depth 215 is clearly the larger of the two speakers. Its body is 224mm wider, 200mm taller and 198mm deeper than KEF KUBE 10b.
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.
MartinLogan Depth 215 needs about 144% more floor or shelf area. MartinLogan Depth 215 is 198mm deeper, so it stands that much further out from the wall. MartinLogan Depth 215 is 200mm 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 MartinLogan Depth 215 is approximately 3451.0cm2 / 534.9inch2 and base area of the KEF KUBE 10b is approximately 1413.3cm2 / 219.1inch2. The Depth 215 requires 144% more surface area than the KUBE 10b 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 MartinLogan Depth 215 weighs 78.50kg / 172.7lbs and the KEF KUBE 10b weighs 17.50kg / 38.5lbs. This makes the Depth 215 349% heavier than the KUBE 10b.
Here is a comparison of how Depth 215 and KUBE 10b's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
 Woofer Size |
15 inches
vs
10 inches
|
Larger woofer |
| Number of Woofers |
2
vs
1
|
More woofers |
| Low Frequency Response |
18 Hz
vs
24 Hz
|
Generates deeper bass |
 High Frequency Response |
140 Hz
vs
120 Hz
|
Generates higher frequency |
 Height |
372mm
vs
572mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1413cm2
vs
3451cm2
|
Takes less floor space |
 Price per pair* |
750USD
vs
7000USD
|
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.
MartinLogan Depth 215 needs about 144% more floor area. MartinLogan Depth 215 stands 198mm further into the room. MartinLogan Depth 215 is 200mm taller.
| General |
MartinLogan Depth 215 |
KEF KUBE 10b |
| Brand |
MartinLogan |
KEF |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
2200 watts |
300 watts |
| Frequency Response |
18-120 Hz |
24-140 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
2200-watt RMS |
300-watt RMS |
| Watts Peak (Max) |
4400-watt RMS |
n/a |
Drivers |
|
|
| Woofer Quantity |
2 |
1 |
| Woofer Size |
15" |
10" |
| Woofer Composition |
Aluminium |
|
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
35–120Hz |
40-140 Hz |
| Firing Direction |
n/a |
front |
Physical Specs |
|
|
| Height |
572.0mm (22.5") |
372.0mm (14.6") |
| Width |
580.0mm (22.8") |
356.0mm (14") |
| Depth |
595.0mm (23.4") |
397.0mm (15.6") |
| Weight |
78.50kg (172.7lbs) |
17.50kg (38.5lbs) |
| Enclosure |
Acoustic Suspension |
Acoustic Suspension |
| Grille |
Yes |
n/a |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
|
2 Years |
| Labor Warranty |
|
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 | A | MartinLogan Depth 215 goes deeper - 18Hz against 24Hz. Under 20Hz is felt more than heard - the bottom of a pipe organ and the bottom of a film mix. |
| Amplifier power | A | MartinLogan Depth 215 has the bigger amplifier - 2200W against 300W RMS, about 8.7dB more on tap. In a large room that is headroom before the DSP starts limiting. |
| Driver area | A | MartinLogan Depth 215 moves more air: 2 x 15" against 10" is 4.5x the cone area, not the 2.12x 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 | A | MartinLogan Depth 215 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. |
| Cabinet size | depends | KEF KUBE 10b 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. |
| Price | B | KEF KUBE 10b costs less - $750 against $7,000, about 89% less. |
A MartinLogan Depth 215 B KEF KUBE 10b
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: MartinLogan Depth 215 measures better, KEF KUBE 10b costs about 89% 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, MartinLogan Depth 215 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 $750 each, two KEF KUBE 10b cost about $1,500 against $7,000 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.