In this review, we will be comparing Flexus Sub 100 and R-121SW, two Powered Subwoofer speakers by 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 Klipsch Flexus Sub 100 and Klipsch R-121SW first before getting into our more detailed comparison.
In the following sections, we will get into details in order to better understand how the Klipsch Flexus Sub 100 and Klipsch R-121SW compare and hopefully end up with enough arguments to decide which one of these subwoofers is the better choice for you.
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Drivers
The efficiency of a subwoofer is directly proportional to the total radiating are squared hence the woofer quantity and diameter.Both Klipsch Flexus Sub 100and Klipsch R-121SW have a single woofer setup however the Klipsch Flexus Sub 100's woofer is 10-inch whereas the Klipsch R-121SW features a 12-inch woofer.
Frequency Response
Flexus Sub 100 has a frequency range of 26-250 Hz whereas R-121SW has a frequency range of 28-120 Hz. With a minimum frequency of 26Hz, the Flexus Sub 100 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
Cabinet Type
The Klipsch Flexus Sub 100 has a Acoustic Suspension type cabinet. Acoustic Suspension aka Sealed type subwoofers have enclosures that are sealed hence no ports or holes exists on the cabinet. Sealed designs helps to provide more accurate and tight bass responses compared to ported designs. On the other hand the Klipsch R-121SW have Bass Reflex type enclosure. 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
Size of a speaker can sometimes become 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 Flexus Sub 100's and Klipsch R-121SW's external dimensions. Klipsch Flexus Sub 100 has external dimensions of 340.0 x 335.0 x 349.0mm ( 13-3/8 x 13-3/16 x 13-3/4inch) 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 72mm wider, 83mm taller and 183mm deeper than Klipsch Flexus Sub 100.
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 Flexus Sub 100 is approximately 1169.2cm2 / 181.2inch2 and base area of the Klipsch R-121SW is approximately 2165.2cm2 / 335.6inch2. The Flexus Sub 100 requires 46% 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 Klipsch Flexus Sub 100 weighs 9.40kg / 20.7lbs and the Klipsch R-121SW weighs 16.00kg / 35.2lbs. This makes the R-121SW 70% heavier than the Flexus Sub 100.
Here is a comparison of how Flexus Sub 100 and R-121SW's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
 Low Frequency Response |
26 Hz
vs
28 Hz
|
Generates deeper bass |
 High Frequency Response |
250k Hz
vs
120k Hz
|
Generates higher frequency |
 Height |
340mm
vs
423mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1169cm2
vs
2165cm2
|
Takes less floor space |
 Price per pair* |
350USD
vs
599USD
|
costs less (*prices may change depending on the seller, location and time) |
 Wireless Operation |
Yes
vs
No
|
Connect your subwoofer to your system wireless |
| Woofer Size |
12 inches
vs
10 inches
|
Larger woofer |
| General |
Klipsch Flexus Sub 100 |
Klipsch Reference R-121SW |
| Brand |
Klipsch |
Klipsch |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
80 watts |
200 watts |
| Frequency Response |
26-250 Hz |
28-120 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
80-watt RMS |
200-watt RMS |
| Watts Peak (Max) |
160-watt RMS |
n/a |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
10" |
12" |
| Woofer Composition |
Paper |
Spun-Copper TCP |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
n/a |
front |
Physical Specs |
|
|
| Height |
340.0mm (13.4") |
423.0mm (16.7") |
| Width |
335.0mm (13.2") |
407.0mm (16") |
| Depth |
349.0mm (13.7") |
532.0mm (20.9") |
| Weight |
9.40kg (20.7lbs) |
16.00kg (35.2lbs) |
| Enclosure |
Acoustic Suspension |
Bass Reflex |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
5 Years |
2 Years |
| Labor Warranty |
5 Years |
2 Years |