In this review, we will be comparing Foundation C1 and Airmotiv C1+, two Passive Center Channel speakers from MartinLogan and Emotiva.
Let's have a brief look at the main features
of MartinLogan Foundation C1 and Emotiva Airmotiv C1+ first before getting into our more
detailed comparison.
| Key Specs | MartinLogan Foundation C1 | Emotiva Airmotiv C1+ |
|---|
| Brand | MartinLogan
United States · founded 1982 | Emotiva
United States · founded 2003 |
|---|
| Design | 2-way | 3-way |
|---|
| Tweeter | 1" Folded Motion Ribbon | 25×32 mm" folded ribbon |
|---|
| Midrange | — | 3" |
|---|
| Woofer | 2 x 5-1/2" Aluminum | 2 x 5.25" woven fiber cone |
|---|
| Frequency response | 53-23k Hz | 50 Hz – 28 kHz |
|---|
| Sensitivity | 91 dB | 89 dB |
|---|
| Impedance | 4 ohms | 4 ohms |
|---|
| Power range | up to 150 watts | Up to 120 watts |
|---|
| Weight | 8.18kg / 18lbs | 8.45kg / 18.6lbs |
|---|
| Dimensions (H x W x D) | 7-5/8" x 20" x 10"
194.0 x 508.0 x 254.0mm | 7-3/4" x 20-1/2" x 8-1/4"
197.0 x 521.0 x 210.0mm |
|---|
What size room are the MartinLogan Foundation C1 and Emotiva Airmotiv C1+ 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 Foundation C1 |
Emotiva Airmotiv C1+ |
| Near-field |
Poor |
Poor |
| Small Room |
Average |
Average |
| Mid-size Room |
Good |
Good |
| Large Room |
Average |
Average |
| Very Large Room |
Poor |
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 Foundation C1 is a 2-way design whereas the Airmotiv C1+ 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 Foundation C1Emotiva Airmotiv C1+
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 Foundation C1 |
Emotiva Airmotiv C1+ |
|
Driver Setup
|
2-way
|
3-way
|
|
Tweeter
|
1-inch
|
25×32 mm-inch
|
|
Midrange
|
- |
1 x 3-inch |
|
Woofer
|
2 x 5-1/2-inch
|
2 x 5.25-inch
|
Foundation C1 features a 1" Gen2 Obsidian Folded Motion Ribbon Tweeter and 2 x 5-1/2" Aluminum Woofer with a Crossover frequency at 2900 Hz - 3200 Hz. On the other hand, the Airmotiv C1+ features a 25×32 mm" folded ribbon Tweeter, a 3" Midrange and 2 x 5.25" woven fiber cone Woofer with a Crossover frequency at 550 Hz and 2600Hz.
Frequency Response
Foundation C1 has a frequency range of 53-23k Hz whereas Airmotiv C1+ has a frequency range of 50 Hz – 28 kHz. With a minimum frequency of 50Hz, the Airmotiv C1+ can go slightly deeper then the Foundation C1's min frequency of 53Hz.
The graph below depicts how these two speakers compare with the max, min and average Low Frequency values of other speakers in the Center Channel class in our database.
Low Frequency
Center Channel 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
Foundation C1 and Airmotiv C1+ have the same Impedance of 4 ohms but where they differ is the sensitivity levels. Foundation C1 sensitivity is rated at 91 dB and the Airmotiv C1+'s is at 89 dB. This 2 dB difference makes the MartinLogan Foundation C1 a more sensitive speaker compared to Emotiva Airmotiv C1+, hence will play louder with the same amount of watts.
One thing to keep in mind that the lower impedance speakers, especially the ones that are rated at 4 ohms may put more pressure on the amplifier unit comared to higher impedance speakers especially at high volume levels, so make sure the amp you pair with the Foundation C1 and the Foundation C1 can provide this impedance level.
Sensitivity
Center Channel 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.
Foundation C1 can handle a max power of 150 watts RMS, whereas Airmotiv C1+ has a max power handling value of 120 watts RMS, 30 watts less than the Foundation C1.
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 Foundation C1
Input Type and Bi-Amping / Bi-Wiring
Airmotiv C1+ features Binding post posts which make bi-amping or bi-wiring possible. Foundation C1 has a Binding post which doesn't feature bi-amping/bi-wiring.
MartinLogan Foundation C1's Binding post terminals
Emotiva Airmotiv C1+'s Binding post terminals allows Bi-amping or bi-wiring
Cabinet Type and Port Position
Both Foundation C1 and Airmotiv C1+ have rear firing ports. Rear ported speakers generally need more room between the backside of the speaker and the wall compared to sealed and front/bottom ported speakers. Placing the speakers too close to the walls may cause the bass to sound boomy.
If you are limited in space and can't get the speakers away from the backwall, check our Speakers with Front Firing Ports page.
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 Foundation C1's and Emotiva Airmotiv C1+'s external dimensions. MartinLogan Foundation C1 has external dimensions of 194.0 x 508.0 x 254.0mm (7-5/8inch x 20inch x 10inch) whereas Emotiva Airmotiv C1+ has external dimensions of 197.0 x 521.0 x 210.0mm (7-3/4 x 20-1/2 x 8-1/4inch).
MartinLogan Foundation C1 is 13mm narrower and 3mm shorter than Emotiva Airmotiv C1+ but it is also 44mm deeper.
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.
MartinLogan Foundation C1 needs about 18% more floor or shelf area. MartinLogan Foundation C1 is 44mm 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 Foundation C1 is approximately 1290.3cm2 / 200.0inch2 and base area of the Emotiva Airmotiv C1+ is approximately 1094.1cm2 / 169.6inch2. The Foundation C1 requires 18% more surface area than the Airmotiv C1+ which gives it a small disadvantage on placement in tight spaces.
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 Foundation C1 weighs 8.18kg / 18lbs and the Emotiva Airmotiv C1+ weighs 8.45kg / 18.6lbs. This makes the Airmotiv C1+ 3% heavier than the Foundation C1.
Here is a comparison of how Foundation C1 and Airmotiv C1+'s weights compare with the average, max and min weights in Passive Center Channel class.
Weight
All Center Channel Speakers
MartinLogan Foundation C1
 Max Input Power |
150 watts
vs
120 watts
|
Handle more power from your amplifier |
 Sensitivity |
91 dB
vs
89 dB
|
Play louder with same amount of amplification power |
 Height |
194mm
vs
197mm
|
Easier to fit in smaller spaces |
 Driver Setup |
3-way
vs
2-way
|
Have a dedicated mid-range driver |
 Woofer Size |
5.25 inches
vs
5-1/2 inches
|
Larger woofer |
|
Low Frequency Response |
50 Hz
vs
53 Hz
|
Generates deeper bass |
 High Frequency Response |
28k Hz
vs
23k Hz
|
Generates higher frequency |
 Bi-Amping and Bi-Wiring |
Yes
vs
No
|
Allows bi-amping and bi-wiring connections |
 Base Surface Area |
1094cm2
vs
1290cm2
|
Takes less floor space |
 Price per pair* |
299USD
vs
499USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
MartinLogan Foundation C1 |
Emotiva Airmotiv C1+ |
| Brand |
MartinLogan |
Emotiva |
| Speaker Type |
Center channel speaker |
Center channel speaker |
| Power Range |
up to 150 watts |
Up to 120 watts |
| Sensitivity |
91 dB |
89 dB |
| Impedance |
4 ohms |
4 ohms |
| Frequency Response |
53-23k Hz |
50 Hz – 28 kHz |
Drivers |
|
|
| Woofer Quantity |
2 |
2 |
| Woofer Size |
5-1/2" |
5.25" |
| Woofer Composition |
Aluminum |
woven fiber cone |
| Tweeter Size |
1" |
25×32 mm" |
| Tweeter Type |
Folded Motion Ribbon |
folded ribbon |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
3" |
| Crossover Frequency |
2900 Hz - 3200 Hz |
550 Hz and 2600Hz |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
194.0mm (7.6") |
197.0mm (7.8") |
| Width |
508.0mm (20") |
521.0mm (20.5") |
| Depth |
254.0mm (10") |
210.0mm (8.3") |
| Weight |
8.18kg (18lbs) |
8.45kg (18.6lbs) |
| Enclosure |
Bass Reflex |
Bass reflex |
| Finish |
n/a |
HDF |
| Available Colors |
Walnut,Black,Satin White |
Black |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
No |
Yes |
Other |
|
|
| Parts Warranty |
5 years |
5 Years |
| Labor Warranty |
5 years |
5 Years |
These sit in different price classes - MartinLogan Foundation C1 costs roughly 1.7x what Emotiva Airmotiv C1+ 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 | Emotiva Airmotiv C1+ digs deeper - 50Hz against 53Hz. A subwoofer would even that out. |
| Amplifier needs | A | MartinLogan Foundation C1 is more sensitive (91dB vs 89dB), so it goes louder on the same amplifier. |
| Headroom | A | MartinLogan Foundation C1 takes more power (150W vs 120W) - more in hand in a big room. |
| Size | depends | Similar cabinet size - neither is easier to fit. |
| Expandability | B | Emotiva Airmotiv C1+: bi-amping. |
| Price | B | Emotiva Airmotiv C1+ is cheaper - $299 against $499, about 40% less; arguably a different class. |
A MartinLogan Foundation C1 B Emotiva Airmotiv C1+
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?
Neither runs away with it - they trade advantages. Let the "depends" rows and your own room settle it. If your amplifier is modest, vintage or valve-based, MartinLogan Foundation C1 is the safer partner - the other will want more current or more watts to sound its best. Think about the whole system, not just the speakers: the roughly $200 saved by taking the cheaper pair would buy a subwoofer or a better amplifier, and either usually does more for the sound than the difference between these two.
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.