KEF R6 Meta vs MartinLogan ESL C Comparison

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KEF R6 Meta

Passive Center Channel | 65-28k Hz

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MartinLogan ESL C

Passive Center Channel | 66-23k Hz

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KEF R6 Meta

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MartinLogan ESL C

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KEF R6 Meta

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MartinLogan ESL C

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KEF R6 Meta vs MartinLogan ESL C Speaker Comparison

In this review, we will be comparing R6 Meta and ElectroMotion ESL C, two Passive Center Channel speakers from KEF and MartinLogan.

Let's have a brief look at the main features of KEF R6 Meta and MartinLogan ESL C first before getting into our more detailed comparison.

Key Specs	KEF R6 Meta	MartinLogan ESL C
Design	3-way	3-way
Uni-Q driver	12th Generation Uni-Q	—
Tweeter	1" Hard-Dome	1 x 1-7/16" Folded Motion
Midrange	5"	9 x 6.375"
Woofer	2 x 6.5" Hybrid Aluminum	2 x 5.25" high-rigidity aluminum woofers
Frequency response	65-28k Hz	66-23k Hz
Sensitivity	88 dB	89 dB
Impedance	4 ohms	4 ohms
Power range	15-250 watts	20-300 watts
Weight	17.82kg / 39.2lbs	14.55kg / 32lbs
Dimensions (H x W x D)	7-15/16" x 24-5/8" x 13-5/16" 202.0 x 626.0 x 339.0mm	7-5/8" x 22-7/8" x 16-1/8" 194.0 x 582.0 x 410.0mm

What size room are the KEF R6 Meta and MartinLogan ESL C 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*	KEF R6 Meta	MartinLogan ESL C
Near-field	Poor	Poor
Small Room	Poor	Poor
Mid-size Room	Good	Good
Large Room	Good	Good
Very Large Room	Average	Average

(* 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.

**This post contains affiliate links, and we will be compensated if you make a purchase after clicking through our links. As an Amazon Associate I earn from qualifying purchases.

Drivers

Both R6 Meta and ElectroMotion ESL C are 3-way speakers.

KEF R6 Meta

MartinLogan ESL C

TweeterMidrangeWoofer

Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.

Driver	KEF R6 Meta	MartinLogan ESL C
Driver Setup	3-way	3-way
Tweeter	1-inch	1 x 1-7/16-inch
Midrange	1 x 5-inch	1 x 9 x 6.375-inch
Woofer	2 x 6.5-inch	2 x 5.25-inch

R6 Meta features a 1" Aluminum with MAT absorber Hard-Dome Tweeter, a 5" Midrange and 2 x 6.5" Hybrid Aluminum Woofer with a Crossover frequency at 500Hz and 2400Hz. On the other hand, the ElectroMotion ESL C features a 1 x 1-7/16" Folded Motion Tweeter, a 9 x 6.375" Midrange and 2 x 5.25" high-rigidity aluminum woofers Woofer.

Frequency Response

R6 Meta has a frequency range of 65-28k Hz whereas ElectroMotion ESL C has a frequency range of 66-23k Hz. With a minimum frequency of 65Hz, the R6 Meta can go slightly deeper then the ElectroMotion ESL C's min frequency of 66Hz.

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

R6 Meta

ElectroMotion ESL C

Min

Average

Median

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

R6 Meta and ElectroMotion ESL C have the same Impedance of 4 ohms but where they differ is the sensitivity levels. R6 Meta sensitivity is rated at 88 dB and the ElectroMotion ESL C's is at 89 dB. This 1 dB difference makes the MartinLogan ESL C a more sensitive speaker compared to KEF R6 Meta, 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 R6 Meta and the R6 Meta can provide this impedance level.

Sensitivity

Center Channel Speakers

R6 Meta

ElectroMotion ESL C

Min

Average

Median

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.

ElectroMotion ESL C can handle a max power of 300 watts RMS, whereas R6 Meta has a max power handling value of 250 watts RMS, 50 watts less than the ElectroMotion ESL C.

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.

Amplifier — change this

Distance

Playing as

KEF R6 Meta

MartinLogan ESL C

Input Type and Bi-Amping / Bi-Wiring

R6 Meta features Custom 5-way bi-wire tool-less binding posts posts which make bi-amping or bi-wiring possible. ElectroMotion ESL C has a Binding post which doesn't feature bi-amping/bi-wiring.

KEF R6 Meta's Custom 5-way bi-wire tool-less binding posts terminals allows Bi-amping or bi-wiring

MartinLogan ESL C's Binding post terminals

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 KEF R6 Meta's and MartinLogan ESL C's external dimensions. KEF R6 Meta has external dimensions of 202.0 x 626.0 x 339.0mm (7-15/16-inch x 24-5/8-inch x 13-5/16-inch) whereas MartinLogan ESL C has external dimensions of 194.0 x 582.0 x 410.0mm (7-5/8 x 22-7/8 x 16-1/8inch).

MartinLogan ESL C is 44mm narrower and 8mm shorter than KEF R6 Meta but it is also 71mm deeper.

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 KEF R6 Meta is approximately 2122.1cm² / 328.9inch² and base area of the MartinLogan ESL C is approximately 2386.2cm² / 369.9inch². The R6 Meta requires 11% less surface area than the ElectroMotion ESL C 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 KEF R6 Meta weighs 17.82kg / 39.2lbs and the MartinLogan ESL C weighs 14.55kg / 32lbs. This makes the R6 Meta 22% heavier than the ElectroMotion ESL C.

Here is a comparison of how R6 Meta and ElectroMotion ESL C's weights compare with the average, max and min weights in Passive Center Channel class.

Weight
All Center Channel Speakers

KEF R6 Meta

MartinLogan ESL C

Min

Average

Max

What's in the Box of KEF R6 Meta?

Here are the items that are included inside the box of R6 Meta:

1 R2 Meta
1 microfiber grille
Rubber feet
User manual and warranty information

What's in the Box of MartinLogan ESL C?

Here are the items that come with the ElectroMotion ESL C:

Center-channel loudspeaker
Grille
AC power supply (attached 10-feet DC cord)
User-feets Manual (En/Fr)
Product Registration Card

Reasons to choose KEF R6 Meta over MartinLogan ElectroMotion ESL C

Woofer Size	6.5 inches vs 5.25 inches	Larger woofer
Low Frequency Response	65 Hz vs 66 Hz	Generates deeper bass
High Frequency Response	28k Hz vs 23k Hz	Generates higher frequency
Base Surface Area	2122cm² vs 2386cm²	Takes less floor space

Reasons to choose MartinLogan ElectroMotion ESL C over KEF R6 Meta

Max Input Power	300 watts vs 250 watts	Handle more power from your amplifier
Sensitivity	89 dB vs 88 dB	Play louder with same amount of amplification power
Height	194mm vs 202mm	Easier to fit in smaller spaces
Price per pair*	1700USD vs 1999USD	costs less (*prices may change depending on the seller, location and time)

KEF R6 Meta vs MartinLogan ESL C Specs Table

Detailed comparison of specifications

General	KEF R6 Meta	MartinLogan ElectroMotion ESL C
Brand	KEF	MartinLogan
Speaker Type	Center channel speaker	Center channel speaker
Power Range	15-250 watts	20-300 watts
Sensitivity	88 dB	89 dB
Impedance	4 ohms	4 ohms
Impedance	3.2 ohms	n/a
Frequency Response	65-28k Hz	66-23k Hz
Drivers
Woofer Quantity	2	2
Woofer Size	6.5"	5.25"
Woofer Composition	Hybrid Aluminum	high-rigidity aluminum woofers
Woofer Surround Material	Rubber	n/a
Tweeter Size	1"	1 x 1-7/16"
Tweeter Type	Hard-Dome	Folded Motion
Aimable Tweeter	No	No
Midrange Driver	5"	9 x 6.375"
Crossover Frequency	500Hz and 2400Hz	n/a
Suggested Break-in Period	n/a	Allow 72 hours of break-in at 90 dB
Physical Specs
Height	202.0mm (8")	194.0mm (7.6")
Width	626.0mm (24.6")	582.0mm (22.9")
Depth	339.0mm (13.3")	410.0mm (16.1")
Weight	17.82kg (39.2lbs)	14.55kg (32lbs)
Enclosure	Sealed	Passive Radiator
Available Colors	Black Gloss, White Gloss, Walnut	Black
Grille	n/a	Yes
Moisture Resistancy	No	No
Connections
Biamp Inputs	Yes	n/a
Other
Parts Warranty	5 years	5 Yrs w/ Registration
Labor Warranty	5 years	5 Yrs w/ Registration

Verdict

A generation apart: KEF R6 Meta is the newer design, against a 2016 model. Newer is not automatically better, but the older one is more likely to be discounted or near run-out.

Area	Better	Why
Bass	evenly matched	Much the same reach (65Hz vs 66Hz).
Amplifier needs	evenly matched	Similar sensitivity (88dB vs 89dB) - both want much the same power.
Headroom	evenly matched	Similar power handling (250W vs 300W).
Size	depends	Similar cabinet size - neither is easier to fit.
Cabinet	depends	Sealed vs Passive Radiator. Sealed is tighter and happier near a wall; ported digs lower but wants space behind it.
Expandability	A	KEF R6 Meta: bi-amping.
Price	B	MartinLogan ESL C is cheaper - $1,700 against $1,999, about 15% less.

A KEF R6 Meta B MartinLogan ESL C
depends neither is better in the abstract - it turns on your room, placement 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?

The usual trade-off: KEF R6 Meta measures better, MartinLogan ESL C costs about 15% less. Whether that gap is worth the money is the call only you can make - and in a normal room it is often smaller than the numbers suggest.

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.