In this review, we will be comparing Dynamo 400 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 400 and JBL Stage A120P first before getting into our more detailed comparison.
In the following sections, we will get into details in order to better understand how the MartinLogan 400 and JBL Stage A120P compare and hopefully end up with enough arguments to decide which one of these subwoofers is the better choice for you.
**This post contains affiliate links, and I will be compensated if you make a purchase after clicking through my links. As an Amazon Associate I earn from qualifying purchases.
Drivers
The efficiency of a subwoofer is directly proportional to the total radiating are squared hence the woofer quantity and diameter.Both MartinLogan 400and JBL Stage A120P have a single woofer setup however the MartinLogan 400's woofer is 8-inch whereas the JBL Stage A120P features a 12-inch woofer.
Frequency Response
Dynamo 400 has a frequency range of 30-200 Hz whereas A120P has a frequency range of 32-150 Hz. With a minimum frequency of 30Hz, the Dynamo 400 can go slightly deeper then 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
Both MartinLogan 400 and JBL Stage A120P have Bass reflex type cabinets.
Physical Specs
Size of a speaker can sometimes become 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 400's and JBL Stage A120P's external dimensions. MartinLogan 400 has external dimensions of 385.0 x 339.0 x 388.0mm ( 15-1/8 x 13-5/16 x 15-1/4inch) 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 54mm wider, 30mm taller and 87mm deeper than MartinLogan 400.
Below you can see the front view size comparison of MartinLogan 400 and JBL Stage A120P in scale.
Comparison image of MartinLogan 400 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 MartinLogan 400 is approximately 1315.3cm2 / 203.9inch2 and base area of the JBL Stage A120P is approximately 1866.8cm2 / 289.4inch2. The Dynamo 400 requires 30% 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 400 weighs 12.95kg / 28.5lbs and the JBL Stage A120P weighs 18.68kg / 41.1lbs. This makes the A120P 44% heavier than the Dynamo 400.
Here is a comparison of how Dynamo 400 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 MartinLogan 400?
Here are the items that are included inside the box of Dynamo 400:
Powered subwoofer6.5-feet AC power cordUser-feets Manual
What's in the Box of JBL Stage A120P?
Here are the items that come with the A120P:
Powered subwooferGrille6-feet AC power cord4 Spike feetOwners ManualWarranty CardImportant Safety Instructions
 Low Frequency Response |
30 Hz
vs
32 Hz
|
Generates deeper bass |
 High Frequency Response |
200k Hz
vs
150k Hz
|
Generates higher frequency |
 Height |
385mm
vs
415mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1315cm2 (339x388mm)
vs
1866cm2 (393x475mm)
|
Takes less floor space |
| Woofer Size |
12 inches
vs
8 inches
|
Larger woofer |
 Price per pair* |
300USD
vs
500USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
MartinLogan Dynamo 400 |
JBL Stage A120P |
| Brand |
MartinLogan |
JBL |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
75 watts |
250 watts |
| Frequency Response |
30-200 Hz |
32-150 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
75-watt RMS |
250-watt RMS |
| Watts Peak (Max) |
n/a |
500-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
8" |
12" |
| Woofer Composition |
Polypropylene |
Polycellulose |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
bottom |
front |
Physical Specs |
|
|
| Height |
385.0mm (15.2") |
415.0mm (16.3") |
| Width |
339.0mm (13.3") |
393.0mm (15.5") |
| Depth |
388.0mm (15.3") |
475.0mm (18.7") |
| Weight |
12.95kg (28.5lbs) |
18.68kg (41.1lbs) |
| Enclosure |
Bass reflex |
Bass reflex |
| Available Colors |
Satin Black |
n/a |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
3 Yrs w/ Registration |
1 Year |
| Labor Warranty |
3 Yrs w/ Registration |
1 Year |