In this review, we will be comparing ProSub 800 and SX-120, two Powered Subwoofer speakers from Definitive Technology and Cambridge Audio. 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 Definitive ProSub 800 and Cambridge Audio SX-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.Definitive ProSub 800and Cambridge Audio SX-120 have the same driver set up: Both subwoofers have 1 x 8" drivers.
Frequency Response
ProSub 800 has a frequency range of 20-150 Hz whereas SX-120 has a frequency range of 34-150 Hz. With a minimum frequency of 20Hz, the ProSub 800 can go significantly deeper on the low side and provide stronger bass compared to the SX-120's min frequency of 34Hz.
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 Definitive ProSub 800 has a Passive Radiator type cabinet. 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. On the other hand the Cambridge Audio SX-120 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.
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 Definitive ProSub 800's and Cambridge Audio SX-120's external dimensions. Definitive ProSub 800 has external dimensions of 328.0 x 262.0 x 423.0mm (12-7/8 x 10-5/16 x 16-5/8inch) whereas Cambridge Audio SX-120 has external dimensions of 296.0 x 297.0 x 350.0mm (11-5/8 x 11-11/16 x 13-3/4inch).
Cambridge Audio SX-120 is 32mm shorter and 73mm less deeper than Definitive ProSub 800 but it is also 35mm wider.
Below you can see the front view size comparison of Definitive ProSub 800 and Cambridge Audio SX-120 in scale.
Comparison image of Definitive ProSub 800 and Cambridge Audio SX-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 Definitive ProSub 800 is approximately 1108.3cm2 / 171.8inch2 and base area of the Cambridge Audio SX-120 is approximately 1039.5cm2 / 161.1inch2. The ProSub 800 requires 7% more surface area than the SX-120 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 Definitive ProSub 800 weighs 11.82kg / 26lbs and the Cambridge Audio SX-120 weighs 7.73kg / 17lbs. This makes the ProSub 800 53% heavier than the SX-120.
Here is a comparison of how ProSub 800 and SX-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 Definitive ProSub 800?
Here are the items that are included inside the box of ProSub 800:
- 8-inch Powered subwoofer
- Detachable grille (installed)
- 7-feet AC power cord
- Owners Manual
- Online Product Registration card
What's in the Box of Cambridge Audio SX-120?
Here are the items that come with the SX-120:
- Powered subwoofer
- 6-feet AC power cord
- Grille
- 4 Spiked feet
- Installation Guide
- Important Safety Instructions
 Low Frequency Response |
20 Hz
vs
34 Hz
|
Generates deeper bass |
 Height |
296mm
vs
328mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1039cm2
vs
1108cm2
|
Takes less floor space |
 Price per pair* |
319USD
vs
399USD
|
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.
Near-identical footprints. Definitive ProSub 800 stands 73mm further into the room. Definitive ProSub 800 is 32mm taller.
| General |
Definitive Technology ProSub 800 |
Cambridge Audio SX-120 |
| Brand |
Definitive Technology |
Cambridge Audio |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
300 watts |
70 watts |
| Frequency Response |
20-150 Hz |
34-150 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
300-watt RMS |
70-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
8" |
8" |
| Woofer Composition |
Polymer |
Treated Paper |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
40-150 Hz and 80 Hz |
n/a |
| Firing Direction |
front |
front |
Physical Specs |
|
|
| Height |
328.0mm (12.9") |
296.0mm (11.7") |
| Width |
262.0mm (10.3") |
297.0mm (11.7") |
| Depth |
423.0mm (16.7") |
350.0mm (13.8") |
| Weight |
11.82kg (26lbs) |
7.73kg (17lbs) |
| Enclosure |
Passive Radiator |
Bass Reflex |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
3 Years |
3 Years |
| Labor Warranty |
3 Years |
3 Years |
A passive radiator 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 | A | Definitive ProSub 800 goes deeper - 20Hz against 34Hz. Under 20Hz is felt more than heard - the bottom of a pipe organ and the bottom of a film mix. |
| Amplifier power | A | Definitive ProSub 800 has the bigger amplifier - 300W against 70W RMS, about 6.3dB more on tap. In a large room that is headroom before the DSP starts limiting. |
| Driver area | evenly matched | Near-identical radiating area (8" against 8"). |
| Enclosure | depends | Definitive ProSub 800 is passive radiator - a passive radiator behaves like a port without the pipe noise, and suits a slim cabinet; Cambridge Audio SX-120 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. |
| Speaker-level inputs | A | Definitive ProSub 800 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. |
| Phase control | B | Cambridge Audio SX-120 has a phase control. Without one, the only way to fix a cancellation at the crossover is to move the box. |
| Price | B | Cambridge Audio SX-120 costs less - $319 against $399, about 20% less. |
A Definitive ProSub 800 B Cambridge Audio SX-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?
The usual trade-off: Definitive ProSub 800 measures better, Cambridge Audio SX-120 costs about 20% less. In a normal room, placement will make a bigger difference than the gap between these two. Check your amplifier first: if it has no subwoofer or preamp output, Definitive ProSub 800 is the only one of these two you can connect at all.
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.