In this review, we will be comparing TZero MKIII and A120P, two Powered Subwoofer speakers from REL 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 REL TZero MKIII 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 REL TZero MKIIIand JBL Stage A120P have a single woofer setup however the REL TZero MKIII's woofer is 6.5-inch whereas the JBL Stage A120P features a 12-inch woofer.
Frequency Response
TZero MKIII has a frequency range of 37-120 Hz whereas A120P has a frequency range of 32-150 Hz. With a minimum frequency of 32Hz, the A120P can go significantly deeper on the low side and provide stronger bass compared to the TZero MKIII's min frequency of 37Hz.
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
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 REL TZero MKIII's and JBL Stage A120P's external dimensions. REL TZero MKIII has external dimensions of 242.9 x 217.5 x 295.3mm () 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).
JBL Stage A120P is clearly the larger of the two speakers. Its body is 175.5mm wider, 172.1mm taller and 179.7mm deeper than REL TZero MKIII.
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 REL TZero MKIII is approximately 642.3cm2 / 99.6inch2 and base area of the JBL Stage A120P is approximately 1866.8cm2 / 289.4inch2. The TZero MKIII requires 66% less surface area than the A120P 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 REL TZero MKIII weighs 6.80kg / 15lbs and the JBL Stage A120P weighs 18.68kg / 41.1lbs. This makes the A120P 175% heavier than the TZero MKIII.
Here is a comparison of how TZero MKIII and A120P's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
 Height |
242mm
vs
415mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
642cm2
vs
1866cm2
|
Takes less floor space |
 Woofer Size |
12 inches
vs
6.5 inches
|
Larger woofer |
| Low Frequency Response |
32 Hz
vs
37 Hz
|
Generates deeper bass |
 High Frequency Response |
150 Hz
vs
120 Hz
|
Generates higher frequency |
 Price per pair* |
300USD
vs
599USD
|
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.
JBL Stage A120P needs about 191% more floor area. JBL Stage A120P stands 180mm further into the room. JBL Stage A120P is 172mm taller.
| General |
REL TZero MKIII |
JBL Stage A120P |
| Brand |
REL |
JBL |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Frequency Response |
37-120 Hz |
32-150 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
100-watt RMS |
250-watt RMS |
| Watts Peak (Max) |
n/a |
500-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
6.5" |
12" |
| Woofer Composition |
|
Polycellulose |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
n/a |
front |
Physical Specs |
|
|
| Height |
242.9mm (9.6") |
415.0mm (16.3") |
| Width |
217.5mm (8.6") |
393.0mm (15.5") |
| Depth |
295.3mm (11.6") |
475.0mm (18.7") |
| Weight |
6.80kg (15lbs) |
18.68kg (41.1lbs) |
| Enclosure |
|
Bass reflex |
| Grille |
n/a |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
3 Years |
1 Year |
| Labor Warranty |
3 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 | B | JBL Stage A120P goes deeper - 32Hz against 37Hz. A real difference, though most music has little content below 37Hz. |
| Amplifier power | B | JBL Stage A120P has the bigger amplifier - 250W against 100W RMS, about 4dB more on tap. In a large room that is headroom before the DSP starts limiting. |
| Driver area | B | JBL Stage A120P moves more air: 12" against 6.5" is 3.41x the cone area, not the 1.85x the diameters suggest. More area means the same output with less excursion, and less distortion with it. |
| Enclosure | depends | REL TZero MKIII 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 | REL TZero MKIII is about 80% 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 | REL TZero MKIII carries 3 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 $599, about 50% less. |
A REL TZero MKIII 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?
JBL Stage A120P is the easier recommendation: it leads on most of the measured areas and costs less. Take REL TZero MKIII if one of the "depends" rows describes your room. 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, REL TZero MKIII 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 $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.