In this review, we will be comparing Dynamo IW-O and Dynamo IW S, two Passive In-wall speakers by MartinLogan. Let's have a brief look at the main features of MartinLogan Dynamo IW-O and MartinLogan Dynamo IW S 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 IW-Oand MartinLogan Dynamo IW S have the same driver set up: Both subwoofers have 2 x 8" drivers.
Frequency Response
Dynamo IW-O has a frequency range of 30-190Hz whereas Dynamo IW S has a frequency range of 35-190 Hz. With a minimum frequency of 30Hz, the Dynamo IW-O can go significantly deeper on the low side and provide stronger bass compared to the Dynamo IW S's min frequency of 35Hz.
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 In-wall class in our database.
Low Frequency
In-wall Speakers
High Frequency
In-wall Speakers
Input Type and Bi-Amping / Bi-Wiring
Dynamo IW-O features Spring post type posts and Dynamo IW S has a Spring post type posts. None of these speakers feature bi-amping/bi-wiring.
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 IW-O's and MartinLogan Dynamo IW S's external dimensions. MartinLogan Dynamo IW-O has external dimensions of 485.4 x 272.5 x 104.1mm () whereas MartinLogan Dynamo IW S has external dimensions of 490.5 x 277.8 x 114.3mm ().
MartinLogan Dynamo IW S is clearly the larger of the two speakers. Its body is 5.3mm wider, 5.1mm taller and 10.2mm deeper than MartinLogan Dynamo IW-O.
Below you can see the front view size comparison of MartinLogan Dynamo IW-O and MartinLogan Dynamo IW S in scale.
Comparison image of MartinLogan Dynamo IW-O and MartinLogan Dynamo IW S Size and External Dimensions
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 IW-O weighs 6.80kg / 15lbs and the MartinLogan Dynamo IW S weighs 12.11kg / 26.6lbs. This makes the Dynamo IW S 78% heavier than the Dynamo IW-O.
Here is a comparison of how Dynamo IW-O and Dynamo IW S's weights compare with the average, max and min weights in Passive In-wall class.
Weight
All In-wall Speakers
 Low Frequency Response |
30 Hz
vs
35 Hz
|
Generates deeper bass |
 Height |
485mm
vs
490mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
283cm2
vs
317cm2
|
Takes less floor space |
 Price per pair* |
1398USD
vs
1600USD
|
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.
MartinLogan Dynamo IW S needs about 12% more floor area.
| General |
MartinLogan Dynamo IW-O |
MartinLogan Dynamo IW S |
| Brand |
MartinLogan |
MartinLogan |
| Speaker Type |
Passive Subwoofer |
Passive Subwoofer |
| Impedance |
8 ohms |
8 ohms |
| Frequency Response |
30-190Hz |
35-190 Hz |
Drivers |
|
|
| Woofer Quantity |
2 |
2 |
| Woofer Size |
8" |
8" |
| Woofer Composition |
|
|
| Woofer Surround Material |
Thermal Plastic Rubber (TPR) |
n/a |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
Physical Specs |
|
|
| Height |
485.4mm (19.1") |
490.5mm (19.3") |
| Width |
272.5mm (10.7") |
277.8mm (10.9") |
| Depth |
104.1mm (4.1") |
114.3mm (4.5") |
| Weight |
6.80kg (15lbs) |
12.11kg (26.6lbs) |
| Enclosure |
|
|
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
No |
n/a |
Other |
|
|
| Parts Warranty |
5 Years |
5 Years |
| Labor Warranty |
5 Years |
5 Years |
Siblings in MartinLogan's Dynamo range - same design thinking, different size. It comes down to your room and your budget.
| Area | Better | Why |
|---|
| Bass depth | A | MartinLogan Dynamo IW-O goes deeper - 30Hz against 35Hz. A real difference, though most music has little content below 35Hz. |
| Driver area | evenly matched | Near-identical radiating area (2 x 8" against 2 x 8"). |
| Price | A | MartinLogan Dynamo IW-O costs less - $1,398 against $1,600, about 13% less. |
A MartinLogan Dynamo IW-O B MartinLogan Dynamo IW S
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?
MartinLogan Dynamo IW-O has the edge on paper, though not by much. The "depends" rows are more likely to decide this than the score is.
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.