In this review, we will be comparing T 9x and KUBE 10b, two Powered Subwoofer speakers from REL 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 REL T 9x 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.REL T 9xand KEF KUBE 10b have the same driver set up: Both subwoofers have 1 x 10" drivers.
Frequency Response
T 9x has a frequency range of 27-120 Hz whereas KUBE 10b has a frequency range of 24-140 Hz. With a minimum frequency of 24Hz, the KUBE 10b can go slightly deeper then the T 9x's min frequency of 27Hz.
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 REL T 9x's and KEF KUBE 10b's external dimensions. REL T 9x has external dimensions of 344.5 x 371.5 x 465.1mm () 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).
KEF KUBE 10b is 15.5mm narrower and 68.1mm less deeper than REL T 9x but it is also 27.5mm 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 REL T 9x is approximately 1727.8cm2 / 267.8inch2 and base area of the KEF KUBE 10b is approximately 1413.3cm2 / 219.1inch2. The T 9x requires 22% 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 REL T 9x weighs 20.64kg / 45.4lbs and the KEF KUBE 10b weighs 17.50kg / 38.5lbs. This makes the T 9x 18% heavier than the KUBE 10b.
Here is a comparison of how T 9x and KUBE 10b's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
 Height |
344mm
vs
372mm
|
Easier to fit in smaller spaces |
 Low Frequency Response |
24 Hz
vs
27 Hz
|
Generates deeper bass |
 High Frequency Response |
140 Hz
vs
120 Hz
|
Generates higher frequency |
 Base Surface Area |
1413cm2
vs
1727cm2
|
Takes less floor space |
 Price per pair* |
750USD
vs
1699USD
|
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.
REL T 9x needs about 22% more floor area. REL T 9x stands 68mm further into the room. KEF KUBE 10b is 28mm taller.
| General |
REL T 9x |
KEF KUBE 10b |
| Brand |
REL |
KEF |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Frequency Response |
27-120 Hz |
24-140 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
300-watt RMS |
300-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
10" |
10" |
| Woofer Composition |
|
|
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
n/a |
40-140 Hz |
| Firing Direction |
n/a |
front |
Physical Specs |
|
|
| Height |
344.5mm (13.6") |
372.0mm (14.6") |
| Width |
371.5mm (14.6") |
356.0mm (14") |
| Depth |
465.1mm (18.3") |
397.0mm (15.6") |
| Weight |
20.64kg (45.4lbs) |
17.50kg (38.5lbs) |
| Enclosure |
|
Acoustic Suspension |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
3 Years |
2 Years |
| Labor Warranty |
3 Years |
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 KUBE 10b goes deeper - 24Hz against 27Hz. A real difference, though most music has little content below 27Hz. |
| Amplifier power | evenly matched | Much the same amplifier (300W vs 300W RMS) - under 1dB apart. |
| Driver area | evenly matched | Near-identical radiating area (10" against 10"). |
| Enclosure | depends | REL T 9x is passive radiator - a passive radiator behaves like a port without the pipe noise, and suits a slim cabinet; KEF KUBE 10b 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. |
| Warranty | A | REL T 9x 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 | B | KEF KUBE 10b costs less - $750 against $1,699, about 56% less. |
A REL T 9x 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?
Neither runs away with it - they trade advantages. Let your room size and where the box can actually stand settle it. Films or music? If this is mainly a home cinema, REL T 9x will hit harder for the money; if it is mainly for music in a normal-sized room, KEF KUBE 10b 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 $750 each, two KEF KUBE 10b cost about $1,500 against $1,699 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.