In this review, we will be comparing Dynamo Foundation 12 and A120P, two Powered Subwoofer speakers from MartinLogan 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 MartinLogan Dynamo Foundation 12 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.MartinLogan Dynamo Foundation 12and JBL Stage A120P have the same driver set up: Both subwoofers have 1 x 12" drivers.
Frequency Response
Dynamo Foundation 12 has a frequency range of 24-200 Hz whereas A120P has a frequency range of 32-150 Hz. With a minimum frequency of 24Hz, the Dynamo Foundation 12 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
MartinLogan Dynamo Foundation 12
High Frequency
Subwoofer Speakers
MartinLogan Dynamo Foundation 12
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 MartinLogan Dynamo Foundation 12's and JBL Stage A120P's external dimensions. MartinLogan Dynamo Foundation 12 has external dimensions of 404.8 x 357.2 x 408.0mm () 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 35.8mm wider, 10.2mm taller and 67mm deeper than MartinLogan Dynamo Foundation 12.
Size, drawn to scale
Both speakers 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 surface and pushed back to the same wall, so the deeper one visibly sticks out further.
JBL Stage A120P needs about 28% more floor or shelf area. JBL Stage A120P is 67mm deeper, so it stands that much further out from the wall.
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 MartinLogan Dynamo Foundation 12 is approximately 1457.4cm2 / 225.9inch2 and base area of the JBL Stage A120P is approximately 1866.8cm2 / 289.4inch2. The Dynamo Foundation 12 requires 22% 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 MartinLogan Dynamo Foundation 12 weighs 13.20kg / 29lbs and the JBL Stage A120P weighs 18.68kg / 41.1lbs. This makes the A120P 42% heavier than the Dynamo Foundation 12.
Here is a comparison of how Dynamo Foundation 12 and A120P's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
MartinLogan Dynamo Foundation 12
 Low Frequency Response |
24 Hz
vs
32 Hz
|
Generates deeper bass |
 High Frequency Response |
200 Hz
vs
150 Hz
|
Generates higher frequency |
 Height |
404mm
vs
415mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1457cm2
vs
1866cm2
|
Takes less floor space |
 Price per pair* |
300USD
vs
800USD
|
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 28% more floor area. JBL Stage A120P stands 67mm further into the room.
| General |
MartinLogan Dynamo Foundation 12 |
JBL Stage A120P |
| Brand |
MartinLogan |
JBL |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Frequency Response |
24-200 Hz |
32-150 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
350-watt RMS |
250-watt RMS |
| Watts Peak (Max) |
700-watt RMS |
500-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
12" |
12" |
| Woofer Composition |
|
Polycellulose |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
n/a |
front |
Physical Specs |
|
|
| Height |
404.8mm (15.9") |
415.0mm (16.3") |
| Width |
357.2mm (14.1") |
393.0mm (15.5") |
| Depth |
408.0mm (16.1") |
475.0mm (18.7") |
| Weight |
13.20kg (29lbs) |
18.68kg (41.1lbs) |
| Enclosure |
|
Bass reflex |
| Grille |
n/a |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
3 Yrs w/ Registration |
1 Year |
| Labor Warranty |
3 Yrs w/ Registration |
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 | MartinLogan Dynamo Foundation 12 goes deeper - 24Hz against 32Hz. That gap covers the lowest notes of a five-string bass and a concert bass drum. |
| Amplifier power | A | MartinLogan Dynamo Foundation 12 has the bigger amplifier - 350W against 250W RMS, about 1.5dB more on tap. In a large room that is headroom before the DSP starts limiting. |
| Driver area | evenly matched | Near-identical radiating area (12" against 12"). |
| Enclosure | depends | MartinLogan Dynamo Foundation 12 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 | MartinLogan Dynamo Foundation 12 is about 24% 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 | MartinLogan Dynamo Foundation 12 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 $800, about 63% less. |
A MartinLogan Dynamo Foundation 12 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: MartinLogan Dynamo Foundation 12 measures better, JBL Stage A120P costs about 63% 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, MartinLogan Dynamo Foundation 12 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 $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.