In this review, we will be comparing SB-4000 and A120P, two Powered Subwoofer speakers from SVS and JBL. 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 SVS SB-4000 and JBL Stage A120P 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 SVS SB-4000and JBL Stage A120P have a single woofer setup however the SVS SB-4000's woofer is 13.5-inch whereas the JBL Stage A120P features a 12-inch woofer.
Frequency Response
SB-4000 has a frequency range of 19-310 Hz whereas A120P has a frequency range of 32-150 Hz. With a minimum frequency of 19Hz, the SB-4000 can go significantly deeper on the low side and provide stronger bass compared to the A120P's min frequency of 32Hz.
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 SVS SB-4000 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 JBL Stage A120P have Bass reflex type enclosure.
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 SVS SB-4000's and JBL Stage A120P's external dimensions. SVS SB-4000 has external dimensions of 466.0 x 453.0 x 532.0mm (18-5/16 x 17-13/16 x 20-15/16inch) whereas JBL Stage A120P has external dimensions of 415.0 x 393.0 x 475.0mm (16-5/16 x 15-7/16 x 18-11/16inch).
SVS SB-4000 is clearly the larger of the two speakers. Its body is 60mm wider, 51mm taller and 57mm deeper than JBL Stage A120P.
Below you can see the front view size comparison of SVS SB-4000 and JBL Stage A120P in scale.
Comparison image of SVS SB-4000 and JBL Stage A120P 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 SVS SB-4000 is approximately 2410.0cm2 / 373.6inch2 and base area of the JBL Stage A120P is approximately 1866.8cm2 / 289.4inch2. The SB-4000 requires 29% more surface area than the A120P 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 SVS SB-4000 weighs 46.50kg / 102.3lbs and the JBL Stage A120P weighs 18.68kg / 41.1lbs. This makes the SB-4000 149% heavier than the A120P.
Here is a comparison of how SB-4000 and A120P's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
What's in the Box of SVS SB-4000?
Here are the items that are included inside the box of SB-4000:
- Powered subwoofer
- Grille
- 6-feet AC power cord
- Remote control
- 4 Elastomer feet
- Owners Manual
- Important Safety Instructions
What's in the Box of JBL Stage A120P?
Here are the items that come with the A120P:
- Powered subwoofer
- Grille
- 6-feet AC power cord
- 4 Spike feet
- Owners Manual
- Warranty Card
- Important Safety Instructions
 Woofer Size |
13.5 inches
vs
12 inches
|
Larger woofer |
| Low Frequency Response |
19 Hz
vs
32 Hz
|
Generates deeper bass |
 High Frequency Response |
310 Hz
vs
150 Hz
|
Generates higher frequency |
 App-Based Control |
iOS,Android
vs
None
|
Control the speaker via an app |
 Height |
415mm
vs
466mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1866cm2
vs
2410cm2
|
Takes less floor space |
 Price per pair* |
300USD
vs
1800USD
|
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.
SVS SB-4000 needs about 29% more floor area. SVS SB-4000 stands 57mm further into the room. SVS SB-4000 is 51mm taller.
| General |
SVS SB-4000 |
JBL Stage A120P |
| Brand |
SVS |
JBL |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
1200 watts |
250 watts |
| Frequency Response |
19-310 Hz |
32-150 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
1200-watt RMS |
250-watt RMS |
| Watts Peak (Max) |
n/a |
500-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
13.5" |
12" |
| Woofer Composition |
Composite/Glass Fiber |
Polycellulose |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
front |
front |
Physical Specs |
|
|
| Height |
466.0mm (18.3") |
415.0mm (16.3") |
| Width |
453.0mm (17.8") |
393.0mm (15.5") |
| Depth |
532.0mm (20.9") |
475.0mm (18.7") |
| Weight |
46.50kg (102.3lbs) |
18.68kg (41.1lbs) |
| Enclosure |
Acoustic Suspension |
Bass reflex |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
5 Years |
1 Year |
| Labor Warranty |
5 Years |
1 Year |
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 | A | SVS SB-4000 goes deeper - 19Hz against 32Hz. Under 20Hz is felt more than heard - the bottom of a pipe organ and the bottom of a film mix. |
| Amplifier power | A | SVS SB-4000 has the bigger amplifier - 1200W against 250W RMS, about 6.8dB more on tap. In a large room that is headroom before the DSP starts limiting. |
| Driver area | A | SVS SB-4000 moves more air: 13.5" against 12" is 1.27x the cone area, not the 1.13x the diameters suggest. More area means the same output with less excursion, and less distortion with it. |
| Enclosure | depends | SVS SB-4000 is sealed - a sealed box rolls off gently and is usually the easier one to integrate in a small or awkward room; JBL Stage A120P 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 | JBL Stage A120P is about 31% 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 | SVS SB-4000 carries 5 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 | JBL Stage A120P costs less - $300 against $1,800, about 83% less. |
A SVS SB-4000 B JBL Stage A120P
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: SVS SB-4000 measures better, JBL Stage A120P costs about 83% 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, JBL Stage A120P will hit harder for the money; if it is mainly for music in a normal-sized room, SVS SB-4000 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 $300 each, two JBL Stage A120P cost about $600 against $1,800 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.