In this review, we will be comparing R-121SW and SX-120, two Powered Subwoofer speakers from Klipsch and Cambridge Audio. 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 Klipsch R-121SW and Cambridge Audio SX-120 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 Klipsch R-121SWand Cambridge Audio SX-120 have a single woofer setup however the Klipsch R-121SW's woofer is 12-inch whereas the Cambridge Audio SX-120 features a 8-inch woofer.
Frequency Response
R-121SW has a frequency range of 28-120 Hz whereas SX-120 has a frequency range of 34-150 Hz. With a minimum frequency of 28Hz, the R-121SW can go significantly deeper on the low side and provide stronger bass compared to the SX-120'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 Klipsch R-121SW and Cambridge Audio SX-120 have Bass Reflex type cabinets. Bass Reflex type subwoofers (aka Ported, Vented or Reflex Port) have enclosures that uses a port, hole or vent cut into the cabinet. Ported designs are generally more efficient than the Sealed designs.
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 Klipsch R-121SW's and Cambridge Audio SX-120's external dimensions. Klipsch R-121SW has external dimensions of 423.0 x 407.0 x 532.0mm (16-5/8inch x 16inch x 20-15/16inch) whereas Cambridge Audio SX-120 has external dimensions of 296.0 x 297.0 x 350.0mm (11-5/8 x 11-11/16 x 13-3/4inch).
Klipsch R-121SW is clearly the larger of the two speakers. Its body is 110mm wider, 127mm taller and 182mm deeper than Cambridge Audio SX-120.
Below you can see the front view size comparison of Klipsch R-121SW and Cambridge Audio SX-120 in scale.
Comparison image of Klipsch R-121SW and Cambridge Audio SX-120 Size and External Dimensions
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 Klipsch R-121SW is approximately 2165.2cm2 / 335.6inch2 and base area of the Cambridge Audio SX-120 is approximately 1039.5cm2 / 161.1inch2. The R-121SW requires 108% more surface area than the SX-120 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 Klipsch R-121SW weighs 16.00kg / 35.2lbs and the Cambridge Audio SX-120 weighs 7.73kg / 17lbs. This makes the R-121SW 107% heavier than the SX-120.
Here is a comparison of how R-121SW and SX-120's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
What's in the Box of Klipsch R-121SW?
Here are the items that are included inside the box of R-121SW:
- Powered subwoofer
- Grille
- 6.5-feet AC power cord
- User Manual
- Important Safety Instructions
- Warranty Information
What's in the Box of Cambridge Audio SX-120?
Here are the items that come with the SX-120:
- Powered subwoofer
- 6-feet AC power cord
- Grille
- 4 Spiked feet
- Installation Guide
- Important Safety Instructions
 Woofer Size |
12 inches
vs
8 inches
|
Larger woofer |
| Low Frequency Response |
28 Hz
vs
34 Hz
|
Generates deeper bass |
 High Frequency Response |
150 Hz
vs
120 Hz
|
Generates higher frequency |
 Height |
296mm
vs
423mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1039cm2
vs
2165cm2
|
Takes less floor space |
 Price per pair* |
319USD
vs
599USD
|
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 108% more floor area. Klipsch R-121SW stands 182mm further into the room. Klipsch R-121SW is 127mm taller.
| General |
Klipsch Reference R-121SW |
Cambridge Audio SX-120 |
| Brand |
Klipsch |
Cambridge Audio |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
200 watts |
70 watts |
| Frequency Response |
28-120 Hz |
34-150 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
200-watt RMS |
70-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
12" |
8" |
| Woofer Composition |
Spun-Copper TCP |
Treated Paper |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
front |
front |
Physical Specs |
|
|
| Height |
423.0mm (16.7") |
296.0mm (11.7") |
| Width |
407.0mm (16") |
297.0mm (11.7") |
| Depth |
532.0mm (20.9") |
350.0mm (13.8") |
| Weight |
16.00kg (35.2lbs) |
7.73kg (17lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
2 Years |
3 Years |
| Labor Warranty |
2 Years |
3 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 | Klipsch R-121SW goes deeper - 28Hz against 34Hz. A real difference, though most music has little content below 34Hz. |
| Amplifier power | A | Klipsch R-121SW has the bigger amplifier - 200W against 70W RMS, about 4.6dB more on tap. In a large room that is headroom before the DSP starts limiting. |
| Driver area | A | Klipsch R-121SW 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 ported designs, so they roll off in much the same way. |
| Cabinet size | depends | Cambridge Audio SX-120 is about 66% 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 | B | Cambridge Audio SX-120 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 | Cambridge Audio SX-120 costs less - $319 against $599, about 47% less. |
A Klipsch R-121SW B Cambridge Audio SX-120
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: Klipsch R-121SW measures better, Cambridge Audio SX-120 costs about 47% less. In a normal room, placement will make a bigger difference than the gap between these two. 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 $319 each, two Cambridge Audio SX-120 cost about $638 against $599 for one of the other, which is worth a thought. If placement is the constraint - a corner, behind a sofa, under a desk - Cambridge Audio SX-120 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.