In this review, we will be comparing S6 and R-121SW, two Powered Subwoofer speakers from Audioengine 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 Audioengine S6 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 Audioengine S6and Klipsch R-121SW have a single woofer setup however the Audioengine S6's woofer is 6-inch whereas the Klipsch R-121SW features a 12-inch woofer.
Frequency Response
S6 has a frequency range of 33-132 Hz whereas R-121SW has a frequency range of 28-120 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 S6's min frequency of 33Hz.
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 Audioengine S6 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
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 Audioengine S6's and Klipsch R-121SW's external dimensions. Audioengine S6 has external dimensions of 250.0 x 221.0 x 281.0mm (9-13/16inch x 8-11/16inch x 11-1/16inch) 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 186mm wider, 173mm taller and 251mm deeper than Audioengine S6.
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 249% more floor or shelf area. Klipsch R-121SW is 251mm deeper, so it stands that much further out from the wall. Klipsch R-121SW is 173mm 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 Audioengine S6 is approximately 621.0cm2 / 96.3inch2 and base area of the Klipsch R-121SW is approximately 2165.2cm2 / 335.6inch2. The S6 requires 71% 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 Audioengine S6 weighs 7.00kg / 15.4lbs and the Klipsch R-121SW weighs 16.00kg / 35.2lbs. This makes the R-121SW 129% heavier than the S6.
Here is a comparison of how S6 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 Audioengine S6?
Here are the items that are included inside the box of S6:
- Powered subwoofer
- Grille
- 6-feet AC power cord
- 6.5-feet Stereo RCA cable
- 6.5-feet Stereo minijack audio cable
- Cloth subwoofer bag
- Cloth cable bag
- Quick Start Guide
- Audioengine brochure
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 |
132 Hz
vs
120 Hz
|
Generates higher frequency |
 Height |
250mm
vs
423mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
621cm2
vs
2165cm2
|
Takes less floor space |
 Price per pair* |
299USD
vs
599USD
|
costs less (*prices may change depending on the seller, location and time) |
 Wireless Operation |
Optional
vs
No
|
Connect your subwoofer to your system wireless |
 Woofer Size |
12 inches
vs
6 inches
|
Larger woofer |
| Low Frequency Response |
28 Hz
vs
33 Hz
|
Generates deeper bass |
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 249% more floor area. Klipsch R-121SW stands 251mm further into the room. Klipsch R-121SW is 173mm taller.
| General |
Audioengine S6 |
Klipsch Reference R-121SW |
| Brand |
Audioengine |
Klipsch |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
140 watts |
200 watts |
| Frequency Response |
33-132 Hz |
28-120 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
140-watt RMS |
200-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
6" |
12" |
| Woofer Composition |
Treated paper |
Spun-Copper TCP |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
front |
front |
Physical Specs |
|
|
| Height |
250.0mm (9.8") |
423.0mm (16.7") |
| Width |
221.0mm (8.7") |
407.0mm (16") |
| Depth |
281.0mm (11.1") |
532.0mm (20.9") |
| Weight |
7.00kg (15.4lbs) |
16.00kg (35.2lbs) |
| Enclosure |
Acoustic Suspension |
Bass Reflex |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
3 Years |
2 Years |
| Labor Warranty |
3 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 | B | Klipsch R-121SW goes deeper - 28Hz against 33Hz. A real difference, though most music has little content below 33Hz. |
| Amplifier power | B | Klipsch R-121SW has the bigger amplifier - 200W against 140W RMS, about 1.5dB 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 6" is 4x the cone area, not the 2x the diameters suggest. More area means the same output with less excursion, and less distortion with it. |
| Enclosure | depends | Audioengine S6 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. |
| Wireless option | depends | Only Audioengine S6 offers a wireless link (as a paid option). It decides where the sub can go if you cannot run a cable, and is worth nothing if you can. |
| Cabinet size | depends | Audioengine S6 is about 83% 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 | Audioengine S6 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 | A | Audioengine S6 costs less - $299 against $599, about 50% less. |
A Audioengine S6 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: Klipsch R-121SW measures better, Audioengine S6 costs about 50% 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, Audioengine S6 is usually the easier one to make sound right. 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 $299 each, two Audioengine S6 cost about $598 against $599 for one of the other, which is worth a thought.
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.