In this review, we will be comparing Abyss 8 and KC62, 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 Abyss 8 and KEF KC62 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 Abyss 8 and KEF KC62 have a totally different setup: the MartinLogan Abyss 8 features 1 x 8-inch drivers whereas the KC62 features 2 x 6.5-inch drivers.
Frequency Response
Abyss 8 has a frequency range of 23-200 Hz whereas KC62 has a frequency range of 11-200 Hz. With a minimum frequency of 11Hz, the KC62 can go significantly deeper on the low side and provide stronger bass compared to the Abyss 8's min frequency of 23Hz.
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 MartinLogan Abyss 8's and KEF KC62's external dimensions. MartinLogan Abyss 8 has external dimensions of 342.9 x 357.2 x 395.3mm () whereas KEF KC62 has external dimensions of 245.0 x 258.0 x 281.0mm (9-5/8inch x 10-1/8inch x 11-1/16inch).
MartinLogan Abyss 8 is clearly the larger of the two speakers. Its body is 99.2mm wider, 97.9mm taller and 114.3mm deeper than KEF KC62.
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 Abyss 8 needs about 95% more floor or shelf area. MartinLogan Abyss 8 is 114mm deeper, so it stands that much further out from the wall. MartinLogan Abyss 8 is 98mm 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 Abyss 8 is approximately 1412.0cm2 / 218.9inch2 and base area of the KEF KC62 is approximately 725.0cm2 / 112.4inch2. The Abyss 8 requires 95% more surface area than the KC62 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 Abyss 8 weighs 21.18kg / 46.6lbs and the KEF KC62 weighs 14.05kg / 30.9lbs. This makes the Abyss 8 51% heavier than the KC62.
Here is a comparison of how Abyss 8 and KC62's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
 Woofer Size |
8 inches
vs
6.5 inches
|
Larger woofer |
 Price per pair* |
1400USD
vs
1500USD
|
costs less (*prices may change depending on the seller, location and time) |
| Number of Woofers |
2
vs
1
|
More woofers |
| Low Frequency Response |
11 Hz
vs
23 Hz
|
Generates deeper bass |
 Height |
245mm
vs
342mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
725cm2
vs
1412cm2
|
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.
MartinLogan Abyss 8 needs about 95% more floor area. MartinLogan Abyss 8 stands 114mm further into the room. MartinLogan Abyss 8 is 98mm taller.
| General |
MartinLogan Abyss 8 |
KEF KC62 |
| Brand |
MartinLogan |
KEF |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Frequency Response |
23-200 Hz |
11-200 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
500-watt RMS |
1000-watt RMS |
| Watts Peak (Max) |
1000-watt RMS |
n/a |
Drivers |
|
|
| Woofer Quantity |
1 |
2 |
| Woofer Size |
8" |
6.5" |
| Woofer Composition |
|
|
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
n/a |
side |
Physical Specs |
|
|
| Height |
342.9mm (13.5") |
245.0mm (9.6") |
| Width |
357.2mm (14.1") |
258.0mm (10.2") |
| Depth |
395.3mm (15.6") |
281.0mm (11.1") |
| Weight |
21.18kg (46.6lbs) |
14.05kg (30.9lbs) |
| Enclosure |
|
Acoustic Suspension |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
3 Years w/ registration |
2 Years |
| Labor Warranty |
3 Years w/ registration |
2 Years |
A passive radiator 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 | B | KEF KC62 goes deeper - 11Hz against 23Hz. Under 20Hz is felt more than heard - the bottom of a pipe organ and the bottom of a film mix. |
| Amplifier power | B | KEF KC62 has the bigger amplifier - 1000W against 500W RMS, about 3dB more on tap. In a large room that is headroom before the DSP starts limiting. |
| Driver area | B | KEF KC62 moves more air: 2 x 6.5" against 8" is 1.32x the cone area, not the 1.15x the diameters suggest. More area means the same output with less excursion, and less distortion with it. |
| Enclosure | depends | MartinLogan Abyss 8 is passive radiator - a passive radiator behaves like a port without the pipe noise, and suits a slim cabinet; KEF KC62 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 KC62 is about 63% 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 | MartinLogan Abyss 8 carries 3 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 | A | MartinLogan Abyss 8 costs less - $1,400 against $1,500, about 7% less. |
A MartinLogan Abyss 8 B KEF KC62
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: KEF KC62 measures better, MartinLogan Abyss 8 costs about 7% 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, MartinLogan Abyss 8 will hit harder for the money; if it is mainly for music in a normal-sized room, KEF KC62 is usually the easier one to make sound right. If placement is the constraint - a corner, behind a sofa, under a desk - KEF KC62 is the one that will actually go there, and a well-placed small subwoofer beats a badly-placed big one every time.
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.