In this review, we will be comparing SPL-120 and C-308ASWi, 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 SPL-120 and Klipsch C-308ASWi 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 SPL-120and Klipsch C-308ASWi have a single woofer setup however the Klipsch SPL-120's woofer is 12-inch whereas the Klipsch C-308ASWi features a 8-inch woofer.
Frequency Response
SPL-120 has a frequency range of 24-125 Hz whereas C-308ASWi has a frequency range of 28-150 Hz. With a minimum frequency of 24Hz, the SPL-120 can go slightly deeper then the C-308ASWi'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 SPL-120 has a Bass Reflex type cabinet. 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. On the other hand the Klipsch C-308ASWi have Passive Radiator type enclosure. Passive Radiator type subwoofers sports a non-powered cone that moves in response to the main woofer to move air out in order to generate stronger bass in a smaller body compared to ported or sealed designs.
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 SPL-120's and Klipsch C-308ASWi's external dimensions. Klipsch SPL-120 has external dimensions of 450.0 x 375.0 x 540.0mm (17-11/16 x 14-3/4 x 21-1/4inch) whereas Klipsch C-308ASWi has external dimensions of 299.0 x 286.0 x 356.0mm (11-3/4 x 11-1/4 x 14inch).
Klipsch SPL-120 is clearly the larger of the two speakers. Its body is 89mm wider, 151mm taller and 184mm deeper than Klipsch C-308ASWi.
Below you can see the front view size comparison of Klipsch SPL-120 and Klipsch C-308ASWi in scale.
Comparison image of Klipsch SPL-120 and Klipsch C-308ASWi 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 SPL-120 is approximately 2025.0cm2 / 313.9inch2 and base area of the Klipsch C-308ASWi is approximately 1018.2cm2 / 157.8inch2. The SPL-120 requires 99% more surface area than the C-308ASWi 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 SPL-120 weighs 20.45kg / 45lbs and the Klipsch C-308ASWi weighs 12.27kg / 27lbs. This makes the SPL-120 67% heavier than the C-308ASWi.
Here is a comparison of how SPL-120 and C-308ASWi'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 SPL-120?
Here are the items that are included inside the box of SPL-120:
- Powered sub
- Grille
- 6.5-feet AC power cord
- User Manual
- Important Safety Instructions
- Warranty Information
What's in the Box of Klipsch C-308ASWi?
Here are the items that come with the C-308ASWi:
- Powered subwoofer
- Grille
- 8-feet AC power cord
- User Manual
 Woofer Size |
12 inches
vs
8 inches
|
Larger woofer |
| Low Frequency Response |
24 Hz
vs
28 Hz
|
Generates deeper bass |
 Price per pair* |
499USD
vs
1299USD
|
costs less (*prices may change depending on the seller, location and time) |
 High Frequency Response |
150 Hz
vs
125 Hz
|
Generates higher frequency |
 Height |
299mm
vs
450mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1018cm2
vs
2025cm2
|
Takes less floor space |
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 SPL-120 needs about 99% more floor area. Klipsch SPL-120 stands 184mm further into the room. Klipsch SPL-120 is 151mm taller.
| General |
Klipsch SPL-120 |
Klipsch C Series C-308ASWi |
| Brand |
Klipsch |
Klipsch |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
300 watts |
300 watts |
| Frequency Response |
24-125 Hz |
28-150 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
300-watt RMS |
300-watt RMS |
| Watts Peak (Max) |
600-watt RMS |
n/a |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
12" |
8" |
| Woofer Composition |
Cerametallic |
Cerametallic |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
front |
front |
Physical Specs |
|
|
| Height |
450.0mm (17.7") |
299.0mm (11.8") |
| Width |
375.0mm (14.8") |
286.0mm (11.3") |
| Depth |
540.0mm (21.3") |
356.0mm (14") |
| Weight |
20.45kg (45lbs) |
12.27kg (27lbs) |
| Enclosure |
Bass Reflex |
Passive Radiator |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
2 Years |
2 Years |
| Labor Warranty |
2 Years |
2 Years |
A ported subwoofer against a passive radiator 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 | A | Klipsch SPL-120 goes deeper - 24Hz against 28Hz. A real difference, though most music has little content below 28Hz. |
| Amplifier power | evenly matched | Much the same amplifier (300W vs 300W RMS) - under 1dB apart. |
| Driver area | A | Klipsch SPL-120 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 | depends | Klipsch SPL-120 is ported - a ported box gives more output low down for its size, at the cost of a steeper roll-off below tuning; Klipsch C-308ASWi is passive radiator - a passive radiator behaves like a port without the pipe noise, and suits a slim cabinet. Neither is better in the abstract; ported tends to suit films and sealed tends to suit music, and both generalisations have exceptions. |
| Speaker-level inputs | B | Klipsch C-308ASWi takes a speaker-level connection as well as line level. That is what lets it work with an integrated amplifier or a vintage receiver that has no subwoofer output at all. |
| Cabinet size | depends | Klipsch C-308ASWi is about 67% 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. |
| Price | A | Klipsch SPL-120 costs less - $499 against $1,299, about 62% less. |
A Klipsch SPL-120 B Klipsch C-308ASWi
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 SPL-120 has the edge on paper, though not by much. The "depends" rows are more likely to decide this than the score is. Check your amplifier first: if it has no subwoofer or preamp output, Klipsch C-308ASWi is the only one of these two you can connect at all. 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 $499 each, two Klipsch SPL-120 cost about $998 against $1,299 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.