In this review, we will be comparing Foundation C1 and ES30, two Passive Center Channel speakers from MartinLogan and Polk Audio.
Let's have a brief look at the main features
of MartinLogan Foundation C1 and Polk ES30 first before getting into our more
detailed comparison.
| Key Specs | MartinLogan Foundation C1 | Polk ES30 |
|---|
| Brand | MartinLogan
United States · founded 1982 | Polk Audio
United States · founded 1972 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" Folded Motion Ribbon | 1" High-res dome |
|---|
| Woofer | 2 x 5-1/2" Aluminum | 2 x 5.5" mica-reinforced polypropylene Dynamic Balance |
|---|
| Frequency response | 53-23k Hz | 55-40k Hz |
|---|
| Sensitivity | 91 dB | 89 dB |
|---|
| Impedance | 4 ohms | 8 ohms |
|---|
| Power range | up to 150 watts | 20-125 watts |
|---|
| Weight | 8.18kg / 18lbs | 8.64kg / 19lbs |
|---|
| Dimensions (H x W x D) | 7-5/8" x 20" x 10"
194.0 x 508.0 x 254.0mm | 7-1/2" x 20-1/16" x 10-5/8"
191.0 x 510.0 x 270.0mm |
|---|
What size room are the MartinLogan Foundation C1 and Polk ES30 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 |
Polk ES30 |
| 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
Both Foundation C1 and ES30 are 2-way speakers.
MartinLogan Foundation C1Polk ES30
TweeterWoofer
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 |
Polk ES30 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
2 x 5-1/2-inch
|
2 x 5.5-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 ES30 features a 1" Terylene High-res dome Tweeter and 2 x 5.5" mica-reinforced polypropylene Dynamic Balance Woofer.
Frequency Response
Foundation C1 has a frequency range of 53-23k Hz whereas ES30 has a frequency range of 55-40k Hz. With a minimum frequency of 53Hz, the Foundation C1 can go slightly deeper then the ES30'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 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 is a 4 ohms speaker compared to the ES30 which has a nominal impedance of 8 ohms. Lower impedance speakers, especially the ones that are rated at 4 ohms may put more pressure on the amplifier unit especially when played at high volume levels, so make sure the amp you pair with the Foundation C1 can provide this impedance level.
These two speakers also have different sensitivity levels. Foundation C1 sensitivity is rated at 91 dB and the ES30's is rated at 89 dB. This 2 dB difference makes the MartinLogan Foundation C1 a more sensitive speaker compared to Polk ES30, hence will play louder with the same amount of watts.
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 ES30 has a max power handling value of 125 watts RMS, 25 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
Foundation C1 features 5-Way post type posts and ES30 has a 5-Way post type posts. None of these speakers feature bi-amping/bi-wiring.
MartinLogan Foundation C1's Binding post terminals
Polk ES30's 5-Way post terminals
Cabinet Type and Port Position
Both Foundation C1 and ES30 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.
Polk ES30 Port
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 Polk ES30'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 Polk ES30 has external dimensions of 191.0 x 510.0 x 270.0mm (7-1/2 x 20-1/16 x 10-5/8inch).
MartinLogan Foundation C1 is 2mm narrower and 16mm less deeper than Polk ES30 but it is also 3mm taller.
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.
Near-identical footprints. Polk ES30 is 16mm 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 Polk ES30 is approximately 1377.0cm2 / 213.4inch2. The Foundation C1 requires 6% less surface area than the ES30 which gives it a small advantage 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 Polk ES30 weighs 8.64kg / 19lbs. This makes the ES30 6% heavier than the Foundation C1.
Here is a comparison of how Foundation C1 and ES30's weights compare with the average, max and min weights in Passive Center Channel class.
Weight
All Center Channel Speakers
MartinLogan Foundation C1
What's in the Box of Polk ES30?
Here are the items that come with the ES30:
- Center-channel loudspeaker
- Grille (attached)
- 4 Self-adhesive rubber feet
- Owners Manual
- Online Product Registration
 Max Input Power |
150 watts
vs
125 watts
|
Handle more power from your amplifier |
 Sensitivity |
91 dB
vs
89 dB
|
Play louder with same amount of amplification power |
 Low Frequency Response |
53 Hz
vs
55 Hz
|
Generates deeper bass |
 Base Surface Area |
1290cm2
vs
1377cm2
|
Takes less floor space |
 Nominal Impedance |
8 ohms
vs
4 ohms
|
Less selective with amplifiers |
|
Woofer Size |
5.5 inches
vs
5-1/2 inches
|
Larger woofer |
 High Frequency Response |
40k Hz
vs
23k Hz
|
Generates higher frequency |
 Height |
191mm
vs
194mm
|
Easier to fit in smaller spaces |
 Price per pair* |
299USD
vs
499USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
MartinLogan Foundation C1 |
Polk Audio Signature Elite ES30 |
| Brand |
MartinLogan |
Polk Audio |
| Speaker Type |
Center channel speaker |
Center channel speaker |
| Power Range |
up to 150 watts |
20-125 watts |
| Sensitivity |
91 dB |
89 dB |
| Impedance |
4 ohms |
8 ohms |
| Frequency Response |
53-23k Hz |
55-40k Hz |
Drivers |
|
|
| Woofer Quantity |
2 |
2 |
| Woofer Size |
5-1/2" |
5.5" |
| Woofer Composition |
Aluminum |
mica-reinforced polypropylene Dynamic Balance |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Folded Motion Ribbon |
High-res dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
2900 Hz - 3200 Hz |
n/a |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
194.0mm (7.6") |
191.0mm (7.5") |
| Width |
508.0mm (20") |
510.0mm (20.1") |
| Depth |
254.0mm (10") |
270.0mm (10.6") |
| Weight |
8.18kg (18lbs) |
8.64kg (19lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
n/a |
MDF, Wood-grain vinyl |
| Available Colors |
Walnut,Black,Satin White |
Black, Walnut, White |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
No |
n/a |
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 Polk ES30 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 | evenly matched | Much the same reach (53Hz vs 55Hz). |
| Amplifier needs | A | MartinLogan Foundation C1 is more sensitive (91dB vs 89dB), so it goes louder on the same amplifier. |
| Amplifier match | B | Polk ES30 is the easier load at 8 ohms; the other is 4 ohms and wants an amplifier rated for it. |
| Headroom | evenly matched | Similar power handling (150W vs 125W). |
| Size | depends | Similar cabinet size - neither is easier to fit. |
| Expandability | depends | Neither adds bi-amping, a sub output or height drivers. Polk ES30 sits in a wider range (12 models), so a matched surround system is easier later. |
| Price | B | Polk ES30 is cheaper - $299 against $499, about 40% less; arguably a different class. |
A MartinLogan Foundation C1 B Polk ES30
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.