In this review, we will be comparing L10cs and R-121SW, two Powered Subwoofer speakers from JBL 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 JBL L10cs 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 JBL L10csand Klipsch R-121SW have a single woofer setup however the JBL L10cs's woofer is 10-inch whereas the Klipsch R-121SW features a 12-inch woofer.
Frequency Response
L10cs has a frequency range of 32-150 Hz whereas R-121SW has a frequency range of 28-120 Hz. With a minimum frequency of 28Hz, the R-121SW can go slightly deeper then the L10cs's min frequency of 32Hz.
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 JBL L10cs and Klipsch R-121SW 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 JBL L10cs's and Klipsch R-121SW's external dimensions. JBL L10cs has external dimensions of 391.0 x 337.0 x 413.0mm (15-3/8inch x 13-1/4inch x 16-1/4inch) 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 70mm wider, 32mm taller and 119mm deeper than JBL L10cs.
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 JBL L10cs is approximately 1391.8cm2 / 215.7inch2 and base area of the Klipsch R-121SW is approximately 2165.2cm2 / 335.6inch2. The L10cs requires 36% 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 JBL L10cs weighs 14.09kg / 31lbs and the Klipsch R-121SW weighs 16.00kg / 35.2lbs. This makes the R-121SW 14% heavier than the L10cs.
Here is a comparison of how L10cs and R-121SW's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
What's in the Box of JBL L10cs?
Here are the items that are included inside the box of L10cs:
- Powered subwoofer
- 6-feet AC power cord
- 4 Spikes
- Quick Start Guide
- Important Safety Instructions
What's in the Box of Klipsch R-121SW?
Here are the items that come with the R-121SW:
- Powered subwoofer
- Grille
- 6.5-feet AC power cord
- User Manual
- Important Safety Instructions
- Warranty Information
 High Frequency Response |
150 Hz
vs
120 Hz
|
Generates higher frequency |
 Height |
391mm
vs
423mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1391cm2
vs
2165cm2
|
Takes less floor space |
 Woofer Size |
12 inches
vs
10 inches
|
Larger woofer |
| Low Frequency Response |
28 Hz
vs
32 Hz
|
Generates deeper bass |
 Price per pair* |
599USD
vs
699USD
|
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 56% more floor area. Klipsch R-121SW stands 119mm further into the room. Klipsch R-121SW is 32mm taller.
| General |
JBL L10cs |
Klipsch Reference R-121SW |
| Brand |
JBL |
Klipsch |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
250 watts |
200 watts |
| Frequency Response |
32-150 Hz |
28-120 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
250-watt RMS |
200-watt RMS |
| Watts Peak (Max) |
500-watt RMS |
n/a |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
10" |
12" |
| Woofer Composition |
Polycellulose |
Spun-Copper TCP |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
bottom |
front |
Physical Specs |
|
|
| Height |
391.0mm (15.4") |
423.0mm (16.7") |
| Width |
337.0mm (13.3") |
407.0mm (16") |
| Depth |
413.0mm (16.3") |
532.0mm (20.9") |
| Weight |
14.09kg (31lbs) |
16.00kg (35.2lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Available Colors |
Natural Walnut,Black Walnut |
n/a |
| Grille |
n/a |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
1 Year |
2 Years |
| Labor Warranty |
1 Year |
2 Years |
No single best subwoofer here. Your room, where the box can physically go, and whether this is mainly for films or mainly for music will settle it long before the specs do.
| Area | Better | Why |
|---|
| Bass depth | B | Klipsch R-121SW goes deeper - 28Hz against 32Hz. A real difference, though most music has little content below 32Hz. |
| Amplifier power | A | JBL L10cs has the bigger amplifier - 250W against 200W RMS, about 1dB 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 | evenly matched | Both are ported designs, so they roll off in much the same way. |
| Driver placement | depends | JBL L10cs fires down and Klipsch R-121SW fires front. A down-firing driver is more forgiving of a grille-less look and of a hard floor; a front-firing one is the safer choice on a thick carpet or a suspended timber floor. |
| Cabinet size | depends | JBL L10cs is about 41% 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 | Klipsch R-121SW carries 2 years on parts against 1 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 $699, about 14% less. |
A JBL L10cs 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?
Klipsch R-121SW is the easier recommendation: it leads on most of the measured areas and costs less. Take JBL L10cs if one of the "depends" rows describes your room. If placement is the constraint - a corner, behind a sofa, under a desk - JBL L10cs 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.