In this review, we will be comparing Alpha S8 and SPL-120, two Powered Subwoofer speakers from PSB 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 PSB Alpha S8 and Klipsch SPL-120 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 PSB Alpha S8and Klipsch SPL-120 have a single woofer setup however the PSB Alpha S8's woofer is 8-inch whereas the Klipsch SPL-120 features a 12-inch woofer.
Frequency Response
Alpha S8 has a frequency range of 35-150 Hz whereas SPL-120 has a frequency range of 24-125 Hz. With a minimum frequency of 24Hz, the SPL-120 can go significantly deeper on the low side and provide stronger bass compared to the Alpha S8's min frequency of 35Hz.
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 PSB Alpha S8 and Klipsch SPL-120 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.
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 PSB Alpha S8's and Klipsch SPL-120's external dimensions. PSB Alpha S8 has external dimensions of 318.0 x 293.0 x 413.0mm (12-1/2 x 11-1/2 x 16-1/4inch) whereas 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).
Klipsch SPL-120 is clearly the larger of the two speakers. Its body is 82mm wider, 132mm taller and 127mm deeper than PSB Alpha S8.
Below you can see the front view size comparison of PSB Alpha S8 and Klipsch SPL-120 in scale.
Comparison image of PSB Alpha S8 and Klipsch SPL-120 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 PSB Alpha S8 is approximately 1210.1cm2 / 187.6inch2 and base area of the Klipsch SPL-120 is approximately 2025.0cm2 / 313.9inch2. The Alpha S8 requires 40% less surface area than the SPL-120 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 PSB Alpha S8 weighs 9.55kg / 21lbs and the Klipsch SPL-120 weighs 20.45kg / 45lbs. This makes the SPL-120 114% heavier than the Alpha S8.
Here is a comparison of how Alpha S8 and SPL-120's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
What's in the Box of PSB Alpha S8?
Here are the items that are included inside the box of Alpha S8:
- Powered subwoofer
- Grille
- 5-feet AC power cord
- 4 Rubber feet
- 4 Spike feet
- 4 Hex-nuts
- Quick Start Guide
- Important Safety Instructions
- Warranty Information
What's in the Box of Klipsch SPL-120?
Here are the items that come with the SPL-120:
- Powered sub
- Grille
- 6.5-feet AC power cord
- User Manual
- Important Safety Instructions
- Warranty Information
 High Frequency Response |
150 Hz
vs
125 Hz
|
Generates higher frequency |
 Height |
318mm
vs
450mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1210cm2
vs
2025cm2
|
Takes less floor space |
 Woofer Size |
12 inches
vs
8 inches
|
Larger woofer |
| Low Frequency Response |
24 Hz
vs
35 Hz
|
Generates deeper bass |
 Price per pair* |
499USD
vs
549USD
|
costs less (*prices may change depending on the seller, location and time) |
 Wireless Operation |
Optional
vs
No
|
Connect your subwoofer to your system wireless |
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 67% more floor area. Klipsch SPL-120 stands 127mm further into the room. Klipsch SPL-120 is 132mm taller.
| General |
PSB Alpha S8 |
Klipsch SPL-120 |
| Brand |
PSB |
Klipsch |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
150 watts |
300 watts |
| Frequency Response |
35-150 Hz |
24-125 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
150-watt RMS |
300-watt RMS |
| Watts Peak (Max) |
n/a |
600-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
8" |
12" |
| Woofer Composition |
Polypropylene |
Cerametallic |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
front |
front |
Physical Specs |
|
|
| Height |
318.0mm (12.5") |
450.0mm (17.7") |
| Width |
293.0mm (11.5") |
375.0mm (14.8") |
| Depth |
413.0mm (16.3") |
540.0mm (21.3") |
| Weight |
9.55kg (21lbs) |
20.45kg (45lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
1 Year |
2 Years |
| Labor Warranty |
1 Year |
2 Years |
Two quite different sizes of subwoofer. Room volume decides this more than anything else on the page: a big driver in a small room is wasted, and a small one in a large room is worked to death.
| Area | Better | Why |
|---|
| Bass depth | B | Klipsch SPL-120 goes deeper - 24Hz against 35Hz. That gap covers the lowest notes of a five-string bass and a concert bass drum. |
| Amplifier power | B | Klipsch SPL-120 has the bigger amplifier - 300W against 150W RMS, about 3dB more on tap. In a large room that is headroom before the DSP starts limiting. |
| Driver area | B | 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 | evenly matched | Both are ported designs, so they roll off in much the same way. |
| Wireless option | depends | Only Klipsch SPL-120 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 | PSB Alpha S8 is about 58% 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 SPL-120 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 SPL-120 costs less - $499 against $549, about 9% less. |
A PSB Alpha S8 B Klipsch SPL-120
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. If placement is the constraint - a corner, behind a sofa, under a desk - PSB Alpha S8 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.