In this review, we will be comparing Installer Series IW6 and CP-WT380IDC, two Passive In-wall speakers from MartinLogan and Monitor Audio.
Let's have a brief look at the main features
of MartinLogan Installer Series IW6 and Monitor Audio CP-WT380IDC first before getting into our more
detailed comparison.
| Key Specs | MartinLogan Installer Series IW6 | Monitor Audio CP-WT380IDC |
|---|
| Brand | MartinLogan
United States · founded 1982 | Monitor Audio
United Kingdom · founded 1972 |
|---|
| Design | 2-way | 3-way |
|---|
| Tweeter | 0.75" Hard-Dome | 1" Hard-Dome |
|---|
| Midrange | — | 4" |
|---|
| Woofer | 6.5" Mineral-filled poly | 8" C-CAM |
|---|
| Frequency response | 55-20kHz | 50-30kHz |
|---|
| Sensitivity | 89 dB | 89 dB |
|---|
| Impedance | 8 ohms | 6 ohms |
|---|
| Power range | 15-60 watts | 30-120 watts |
|---|
| Weight | 1.59kg / 3.5lbs | 5.67kg / 12.5lbs |
|---|
| Dimensions (H x W x D) | 10.1250" x 7.0625" x 3.1875"
258.0 x 180.0 x 81.0mm | 17.1875" x 10.5625" x 3.8750"
437.0 x 269.0 x 99.0mm |
|---|
What size room are the MartinLogan Installer Series IW6 and Monitor Audio CP-WT380IDC speakers good for?
The size of the room in which you are planning to use these loudspeakers is an important decision
factor. Here we have compared their suitability to various sizes of environments considering their size
and max power parameters:
| Listening Environment* |
MartinLogan Installer Series IW6 |
Monitor Audio CP-WT380IDC |
| Near-field |
Good |
Poor |
| Small Room |
Good |
Average |
| Mid-size Room |
Average |
Good |
| Large Room |
Poor |
Average |
| Very Large Room |
No way |
Poor |
(* Approximate Room sizes: Small < 100sq. ft / 9 m2,
Mid-size: 100-220 sq. ft / 9-20 m2, Large 220-400 sq. ft / 20-36 m2, Very Large: >
400 sq. ft / 36 m2.
Average Floor Height: 9" / 2.7m. Typical room sizes differ from country to country, and the actual
listening experience changes depending on floor height, room shape, surface materials, listening
position, speaker locations, etc.)
The sections below take each area in turn: drivers, frequency response, physical size and what you get in the box.
Drivers
One of the fundamental differences between these two speakers is that Installer Series IW6 is a 2-way design whereas the CP-WT380IDC is a 3-way speaker. 3-way designs utilize a midrange driver in addition to the tweeter and woofer on 2-way designs. Designing a crossover for a 3-way speaker is a complicated process and generally increases the overall cost of the speaker.
MartinLogan Installer Series IW6Monitor Audio CP-WT380IDC
TweeterMidrangeWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
MartinLogan Installer Series IW6 |
Monitor Audio CP-WT380IDC |
|
Driver Setup
|
2-way
|
3-way
|
|
Tweeter
|
0.75-inch
|
1-inch
|
|
Midrange
|
- |
1 x 4-inch |
|
Woofer
|
1 x 6.5-inch
|
1 x 8-inch
|
Installer Series IW6 features a 0.75" Hard-Dome Tweeter and 1 x 6.5" Mineral-filled poly Woofer. On the other hand, the CP-WT380IDC features a 1" Hard-Dome Tweeter, a 4" Midrange and 1 x 8" C-CAM Woofer.
Frequency Response
Installer Series IW6 has a frequency range of 55-20kHz whereas CP-WT380IDC has a frequency range of 50-30kHz. With a minimum frequency of 50Hz, the CP-WT380IDC can go significantly deeper on the low side and provide stronger bass compared to the Installer Series IW6's min frequency of 55Hz.
The graph below depicts how these two speakers compare with the max, min and average Low Frequency values of other speakers in the In-wall class in our database.
Low Frequency
In-wall Speakers
Neither pair reaches down to 20Hz, the usual definition of full-range, which is normal for speakers of this size. If you want the bottom octave for movies or bass-heavy music, add a subwoofer to whichever you choose. Visit our Powered Subwoofers section to find out more about the available options.
Impedance and Sensitivity
Installer Series IW6 is a 8 ohms speaker compared to the CP-WT380IDC which has a nominal impedance of 6 ohms.
On the other hand, they have the same sensitivity of 89 dBdB.
Sensitivity
In-wall Speakers
Power Range
Power
range is the range of input power in watts RMS that a loudspeaker is designed to handle. Staying
within that range gives nominal performance; driving the speaker beyond its maximum wattage can damage it.
CP-WT380IDC can handle a max power of 120 watts RMS, whereas Installer Series IW6 has a max power handling value of 60 watts RMS, 60 watts less than the CP-WT380IDC.
Note that higher power handling does not make a speaker louder: that depends mainly on
sensitivity and impedance. The calculator below shows how loud each of these actually plays
on a real amplifier.
Which plays louder on your amplifier?
Starting with a popular amplifier - change it to the one you own, or any you are
considering, and watch both numbers move.
MartinLogan Installer Series IW6
Monitor Audio CP-WT380IDC
Input Type and Bi-Amping / Bi-Wiring
Installer Series IW6 features Spring post type posts and CP-WT380IDC 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 Installer Series IW6's and Monitor Audio CP-WT380IDC's external dimensions. MartinLogan Installer Series IW6 has external dimensions of 258.0 x 180.0 x 81.0mm (10.1250-inch x 7.0625-inch x 3.1875-inch) whereas Monitor Audio CP-WT380IDC has external dimensions of 437.0 x 269.0 x 99.0mm (17.1875-inch x 10.5625-inch x 3.8750-inch).
Monitor Audio CP-WT380IDC is clearly the larger of the two speakers. Its body is 89mm wider, 179mm taller and 18mm deeper than MartinLogan Installer Series IW6.
Below you can see the front view size comparison of MartinLogan Installer Series IW6 and Monitor Audio CP-WT380IDC in scale.
Comparison image of MartinLogan Installer Series IW6 and Monitor Audio CP-WT380IDC Size and External Dimensions
Weight Comparison The weight of a loudspeaker can become an important factor if you need to move and reposition the unit often. Weight of a speaker can also "sometimes" be an indicator of the rigidity of the enclosure and the quality of the internal components used. The MartinLogan Installer Series IW6 weighs 1.59kg / 3.5lbs and the Monitor Audio CP-WT380IDC weighs 5.67kg / 12.5lbs. This makes the CP-WT380IDC 257% heavier than the Installer Series IW6.
Here is a comparison of how Installer Series IW6 and CP-WT380IDC's weights compare with the average, max and min weights in Passive In-wall class.
Weight
All In-wall Speakers
MartinLogan Installer Series IW6
Monitor Audio CP-WT380IDC
What's in the Box of MartinLogan Installer Series IW6?
Here are the items that are included inside the box of Installer Series IW6:
- In-wall loudspeaker
- Grille
- User-feets Manual
- Cutout Template
What's in the Box of Monitor Audio CP-WT380IDC?
Here are the items that come with the CP-WT380IDC:
- In-Wall speaker
- Magnetic grille
- Paint skim
- Installation Guide
- Important Safety Instructions
- Limited Warranty/Registration Card
- MountingTemplate
 Nominal Impedance |
8 ohms
vs
6 ohms
|
Less selective with amplifiers |
 Height |
258mm
vs
437mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
145cm2
vs
266cm2
|
Takes less floor space |
 Price per pair* |
560USD
vs
2350USD
|
costs less (*prices may change depending on the seller, location and time) |
 Max Input Power |
120 watts
vs
60 watts
|
Handle more power from your amplifier |
 Driver Setup |
3-way
vs
2-way
|
Have a dedicated mid-range driver |
 Woofer Size |
8 inches
vs
6.5 inches
|
Larger woofer |
|
Low Frequency Response |
50 Hz
vs
55 Hz
|
Generates deeper bass |
 High Frequency Response |
30k Hz
vs
20k Hz
|
Generates higher frequency |
| General |
MartinLogan Installer Series IW6 |
Monitor Audio CP-WT380IDC |
| Brand |
MartinLogan |
Monitor Audio |
| Speaker Type |
Passive In-wall Speaker |
Passive In-wall Speaker |
| Power Range |
15-60 watts |
30-120 watts |
| Sensitivity |
89 dB |
89 dB |
| Impedance |
8 ohms |
6 ohms |
| Frequency Response |
55-20kHz |
50-30kHz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
6.5" |
8" |
| Woofer Composition |
Mineral-filled poly |
C-CAM |
| Woofer Surround Material |
Rubber |
Rubber |
| Tweeter Size |
0.75" |
1" |
| Tweeter Type |
Hard-Dome |
Hard-Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
4" |
Physical Specs |
|
|
| Height |
258.0mm (10.2") |
437.0mm (17.2") |
| Width |
180.0mm (7.1") |
269.0mm (10.6") |
| Depth |
81.0mm (3.2") |
99.0mm (3.9") |
| Weight |
1.59kg (3.5lbs) |
5.67kg (12.5lbs) |
| Enclosure |
In-wall |
In-wall |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
No |
No |
Other |
|
|
| Parts Warranty |
5 Yrs w/ Registration |
Lifetime |
| Labor Warranty |
5 Yrs w/ Registration |
Lifetime |
These sit in different price classes - Monitor Audio CP-WT380IDC costs roughly 4.2x what MartinLogan Installer Series IW6 does. Expect it to lead on paper; the question is whether the gap is audible enough in your room to be worth it.
| Area | Better | Why |
|---|
| Bass | B | Monitor Audio CP-WT380IDC digs deeper - 50Hz against 55Hz. A subwoofer would even that out. |
| Amplifier needs | evenly matched | Similar sensitivity (89dB vs 89dB) - both want much the same power. |
| Amplifier match | A | MartinLogan Installer Series IW6 is the easier load at 8 ohms. |
| Headroom | B | Monitor Audio CP-WT380IDC takes more power (120W vs 60W) - more in hand in a big room. |
| Size | depends | MartinLogan Installer Series IW6 is easier to place; Monitor Audio CP-WT380IDC is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability | depends | Neither adds bi-amping, a sub output or height drivers. Monitor Audio CP-WT380IDC sits in a wider range (5 models), so a matched surround system is easier later. |
| Price | A | MartinLogan Installer Series IW6 is cheaper - $560 against $2,350, about 76% less; arguably a different class. |
A MartinLogan Installer Series IW6 B Monitor Audio CP-WT380IDC
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 speakers are judged; anything missing on either side is left out rather than guessed.
Which should you choose?
Monitor Audio CP-WT380IDC is ahead, but only on 1 of the measured areas, and it costs about 4.2x the price. That is a lot of money for a narrow margin on paper - MartinLogan Installer Series IW6 looks like the sensible buy unless something else about the Monitor Audio CP-WT380IDC appeals to you. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 55Hz anyway, which makes the cheaper MartinLogan Installer Series IW6 much easier to justify. Match it to your room: we rate MartinLogan Installer Series IW6 the better fit for near-field listening and a small room, and Monitor Audio CP-WT380IDC for a mid-size room and a large room.
And remember what a spec sheet cannot show: how each looks in your room and whether the finish suits it, what dealer support and warranty are like where you live, and how they actually sound to you. If you can hear them first - ideally with your own music - that will tell you more than any number above.