In this review, we will be comparing Q SUB120 and R-121SW, two Powered Subwoofer speakers from Q Acoustics 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 Q Acoustics Q SUB120 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.Q Acoustics Q SUB120and Klipsch R-121SW have the same driver set up: Both subwoofers have 1 x 12" drivers.
Frequency Response
Q SUB120 has a frequency range of 28-250 Hz whereas R-121SW has a frequency range of 28-120 Hz.
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 Q Acoustics Q SUB120 has a Infinite Baffle type cabinet. 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
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 Q Acoustics Q SUB120's and Klipsch R-121SW's external dimensions. Q Acoustics Q SUB120 has external dimensions of 400.0 x 400.0 x 432.0mm (15-3/4 x 15-3/4 x 17inch) 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 7mm wider, 23mm taller and 100mm deeper than Q Acoustics Q SUB120.
Size, drawn to scale
Both speakers 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 surface and pushed back to the same wall, so the deeper one visibly sticks out further.
Klipsch R-121SW needs about 25% more floor or shelf area. Klipsch R-121SW is 100mm deeper, so it stands that much further out from the wall. Klipsch R-121SW is 23mm 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 Q Acoustics Q SUB120 is approximately 1728.0cm2 / 267.8inch2 and base area of the Klipsch R-121SW is approximately 2165.2cm2 / 335.6inch2. The Q SUB120 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 Q Acoustics Q SUB120 weighs 22.50kg / 49.5lbs and the Klipsch R-121SW weighs 16.00kg / 35.2lbs. This makes the Q SUB120 41% heavier than the R-121SW.
Here is a comparison of how Q SUB120 and R-121SW's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
 High Frequency Response |
250 Hz
vs
120 Hz
|
Generates higher frequency |
 Height |
400mm
vs
423mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1728cm2
vs
2165cm2
|
Takes less floor space |
 Price per pair* |
599USD
vs
799USD
|
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 100mm further into the room. Klipsch R-121SW is 23mm taller.
| General |
Q Acoustics Q SUB120 |
Klipsch Reference R-121SW |
| Brand |
Q Acoustics |
Klipsch |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
300 watts |
200 watts |
| Frequency Response |
28-250 Hz |
28-120 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
300-watt RMS |
200-watt RMS |
| Watts Peak (Max) |
600-watt RMS |
n/a |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
12" |
12" |
| Woofer Composition |
Paper composite |
Spun-Copper TCP |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
n/a |
front |
Physical Specs |
|
|
| Height |
400.0mm (15.7") |
423.0mm (16.7") |
| Width |
400.0mm (15.7") |
407.0mm (16") |
| Depth |
432.0mm (17") |
532.0mm (20.9") |
| Weight |
22.50kg (49.5lbs) |
16.00kg (35.2lbs) |
| Enclosure |
Infinite Baffle |
Bass Reflex |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
5 Years |
2 Years |
| Labor Warranty |
5 Years |
2 Years |
A sealed 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 (28Hz vs 28Hz). |
| Amplifier power | A | Q Acoustics Q SUB120 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 | evenly matched | Near-identical radiating area (12" against 12"). |
| Enclosure | depends | Q Acoustics Q SUB120 is sealed - a sealed box rolls off gently and is usually the easier one to integrate in a small or awkward room; 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 | Q Acoustics Q SUB120 is about 25% 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 | Q Acoustics Q SUB120 carries 5 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 $799, about 25% less. |
A Q Acoustics Q SUB120 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?
The usual trade-off: Q Acoustics Q SUB120 measures better, Klipsch R-121SW costs about 25% less. In a normal room, placement will make a bigger difference than the gap between these two. Films or music? If this is mainly a home cinema, Klipsch R-121SW will hit harder for the money; if it is mainly for music in a normal-sized room, Q Acoustics Q SUB120 is usually the easier one to make sound right.
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.