In this review, we will be comparing T 9x SE and R-121SW, two Powered Subwoofer speakers from REL and Klipsch. 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 SE and Klipsch R-121SW 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 REL T 9x SEand Klipsch R-121SW have a single woofer setup however the REL T 9x SE's woofer is 10-inch whereas the Klipsch R-121SW features a 12-inch woofer.
Frequency Response
T 9x SE has a frequency range of 27-120 Hz whereas R-121SW has a frequency range of 28-120 Hz. With a minimum frequency of 27Hz, the T 9x SE can go slightly deeper then the R-121SW's min frequency of 28Hz.
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
Klipsch R-121SW Port
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 SE's and Klipsch R-121SW's external dimensions. REL T 9x SE has external dimensions of 344.5 x 371.5 x 465.1mm () whereas Klipsch R-121SW has external dimensions of 423.0 x 407.0 x 532.0mm (16-5/8inch x 16inch x 20-15/16inch).
Klipsch R-121SW is clearly the larger of the two speakers. Its body is 35.5mm wider, 78.5mm taller and 66.9mm deeper than REL T 9x SE.
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 SE is approximately 1727.8cm2 / 267.8inch2 and base area of the Klipsch R-121SW is approximately 2165.2cm2 / 335.6inch2. The T 9x SE requires 20% less surface area than the R-121SW 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 REL T 9x SE weighs 20.64kg / 45.4lbs and the Klipsch R-121SW weighs 16.00kg / 35.2lbs. This makes the T 9x SE 29% heavier than the R-121SW.
Here is a comparison of how T 9x SE and R-121SW's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
 Low Frequency Response |
27 Hz
vs
28 Hz
|
Generates deeper bass |
 Height |
344mm
vs
423mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1727cm2
vs
2165cm2
|
Takes less floor space |
| Woofer Size |
12 inches
vs
10 inches
|
Larger woofer |
 Price per pair* |
599USD
vs
1799USD
|
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.
Klipsch R-121SW needs about 25% more floor area. Klipsch R-121SW stands 67mm further into the room. Klipsch R-121SW is 79mm taller.
| General |
REL T 9x SE |
Klipsch Reference R-121SW |
| Brand |
REL |
Klipsch |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Frequency Response |
27-120 Hz |
28-120 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
300-watt RMS |
200-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
10" |
12" |
| Woofer Composition |
|
Spun-Copper TCP |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
n/a |
front |
Physical Specs |
|
|
| Height |
344.5mm (13.6") |
423.0mm (16.7") |
| Width |
371.5mm (14.6") |
407.0mm (16") |
| Depth |
465.1mm (18.3") |
532.0mm (20.9") |
| Weight |
20.64kg (45.4lbs) |
16.00kg (35.2lbs) |
| Enclosure |
|
Bass Reflex |
| Grille |
n/a |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
3 Years |
2 Years |
| Labor Warranty |
3 Years |
2 Years |
A passive radiator subwoofer against a ported 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 | evenly matched | Effectively the same reach (27Hz vs 28Hz). |
| Amplifier power | A | REL T 9x SE has the bigger amplifier - 300W against 200W RMS, about 1.8dB more on tap. In a large room that is headroom before the DSP starts limiting. |
| Driver area | B | Klipsch R-121SW moves more air: 12" against 10" is 1.44x the cone area, not the 1.2x the diameters suggest. More area means the same output with less excursion, and less distortion with it. |
| Enclosure | depends | REL T 9x SE is passive radiator - a passive radiator behaves like a port without the pipe noise, and suits a slim cabinet; Klipsch R-121SW is ported - a ported box gives more output low down for its size, at the cost of a steeper roll-off below tuning. 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 | REL T 9x SE is about 35% 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 | REL T 9x SE 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 | Klipsch R-121SW costs less - $599 against $1,799, about 67% less. |
A REL T 9x SE B Klipsch R-121SW
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?
REL T 9x SE is ahead, but on only 1 of the measured areas, and it costs about 3x the price. Klipsch R-121SW is the sensible buy unless your room is large enough to need the extra. 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 $599 each, two Klipsch R-121SW cost about $1,198 against $1,799 for one of the other, which is worth a thought. If placement is the constraint - a corner, behind a sofa, under a desk - REL T 9x SE 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.