In this review, we will be comparing Reference 4 Meta and Airmotiv C1+, two Passive Center Channel speakers from KEF and Emotiva.
Let's have a brief look at the main features
of KEF Reference 4 Meta and Emotiva Airmotiv C1+ first before getting into our more
detailed comparison.
| Key Specs | KEF Reference 4 Meta | Emotiva Airmotiv C1+ |
|---|
| Brand | KEF
United Kingdom · founded 1961 | Emotiva
United States · founded 2003 |
|---|
| Design | 3-way | 3-way |
|---|
| Uni-Q driver | 12th Generation Uni-Q | — |
|---|
| Tweeter | 1" aluminium dome with MAT | 25×32 mm" folded ribbon |
|---|
| Midrange | 5" | 3" |
|---|
| Woofer | 4 x 6.5" aluminium cone | 2 x 5.25" woven fiber cone |
|---|
| Frequency response | 48-35k Hz | 50 Hz – 28 kHz |
|---|
| Sensitivity | 88 dB | 89 dB |
|---|
| Impedance | 4 ohms | 4 ohms |
|---|
| Power range | 50-400 watts | Up to 120 watts |
|---|
| Weight | 45.20kg / 99.4lbs | 8.45kg / 18.6lbs |
|---|
| Dimensions (H x W x D) | 8.1" x 42.9" x 18.2"
205 x 1090 x 463 mm | 7-3/4" x 20-1/2" x 8-1/4"
197.0 x 521.0 x 210.0mm |
|---|
What size room are the KEF Reference 4 Meta 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* |
KEF Reference 4 Meta |
Emotiva Airmotiv C1+ |
| Near-field |
Are you nuts? |
Poor |
| Small Room |
Bad |
Average |
| Mid-size Room |
Poor |
Good |
| Large Room |
Good |
Average |
| Very Large Room |
Good |
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 Reference 4 Meta and Airmotiv C1+ are 3-way speakers.
KEF Reference 4 MetaEmotiva 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 |
KEF Reference 4 Meta |
Emotiva Airmotiv C1+ |
|
Driver Setup
|
3-way
|
3-way
|
|
Tweeter
|
1-inch
|
25×32 mm-inch
|
|
Midrange
|
1 x 5-inch |
1 x 3-inch |
|
Woofer
|
4 x 6.5-inch
|
2 x 5.25-inch
|
Reference 4 Meta features a 1" aluminium dome with MAT Tweeter, a 5" Midrange and 4 x 6.5" aluminium cone Woofer with a Crossover frequency at 450Hz and 2100Hz. 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
Reference 4 Meta has a frequency range of 48-35k Hz whereas Airmotiv C1+ has a frequency range of 50 Hz – 28 kHz. With a minimum frequency of 48Hz, the Reference 4 Meta can go slightly deeper then the Airmotiv C1+'s min frequency of 50Hz.
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
Reference 4 Meta and Airmotiv C1+ have the same Impedance of 4 ohms but where they differ is the sensitivity levels. Reference 4 Meta sensitivity is rated at 88 dB and the Airmotiv C1+'s is at 89 dB. This 1 dB difference makes the Emotiva Airmotiv C1+ a more sensitive speaker compared to KEF Reference 4 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 Reference 4 Meta and the Reference 4 Meta 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.
Reference 4 Meta can handle a max power of 400 watts RMS, whereas Airmotiv C1+ has a max power handling value of 120 watts RMS, 280 watts less than the Reference 4 Meta.
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.
Input Type and Bi-Amping / Bi-Wiring
Both Reference 4 Meta and Airmotiv C1+ features dual binding post speaker terminals for bi-amping or bi-wiring.
KEF Reference 4 Meta's Custom 5-way bi-wire tool-less binding posts terminals allows Bi-amping or bi-wiring
Emotiva Airmotiv C1+'s Binding post terminals allows Bi-amping or bi-wiring
Cabinet Type and Port Position
Both Reference 4 Meta 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 KEF Reference 4 Meta's and Emotiva Airmotiv C1+'s external dimensions. KEF Reference 4 Meta has external dimensions of 205 x 1090 x 463 mm (8.1 x 42.9 x 18.2 in.) 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).
KEF Reference 4 Meta is clearly the larger of the two speakers. Its body is 569mm wider, 8mm taller and 253mm deeper than Emotiva Airmotiv C1+.
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.
KEF Reference 4 Meta needs about 361% more floor or shelf area. KEF Reference 4 Meta is 253mm 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 KEF Reference 4 Meta is approximately 5046.7cm2 / 782.2inch2 and base area of the Emotiva Airmotiv C1+ is approximately 1094.1cm2 / 169.6inch2. The Reference 4 Meta requires 361% 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 KEF Reference 4 Meta weighs 45.20kg / 99.4lbs and the Emotiva Airmotiv C1+ weighs 8.45kg / 18.6lbs. This makes the Reference 4 Meta 435% heavier than the Airmotiv C1+.
Here is a comparison of how Reference 4 Meta and Airmotiv C1+'s weights compare with the average, max and min weights in Passive Center Channel class.
Weight
All Center Channel Speakers
 Max Input Power |
400 watts
vs
120 watts
|
Handle more power from your amplifier |
 Woofer Size |
6.5 inches
vs
5.25 inches
|
Larger woofer |
|
Number of Woofers |
4
vs
2
|
More woofers |
|
Low Frequency Response |
48 Hz
vs
50 Hz
|
Generates deeper bass |
 High Frequency Response |
35k Hz
vs
28k Hz
|
Generates higher frequency |
 Sensitivity |
89 dB
vs
88 dB
|
Play louder with same amount of amplification power |
 Height |
197mm
vs
205mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1094cm2
vs
5046cm2
|
Takes less floor space |
 Price per pair* |
299USD
vs
8000USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
KEF Reference 4 Meta |
Emotiva Airmotiv C1+ |
| Brand |
KEF |
Emotiva |
| Speaker Type |
Center channel speaker |
Center channel speaker |
| Power Range |
50-400 watts |
Up to 120 watts |
| Sensitivity |
88 dB |
89 dB |
| Impedance |
4 ohms |
4 ohms |
| Impedance |
3.2 ohms |
n/a |
| Frequency Response |
48-35k Hz |
50 Hz – 28 kHz |
Drivers |
|
|
| Woofer Quantity |
4 |
2 |
| Woofer Size |
6.5" |
5.25" |
| Woofer Composition |
aluminium cone |
woven fiber cone |
| Woofer Surround Material |
Rubber |
n/a |
| Tweeter Size |
1" |
25×32 mm" |
| Tweeter Type |
aluminium dome with MAT |
folded ribbon |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
5" |
3" |
| Crossover Frequency |
450Hz and 2100Hz |
550 Hz and 2600Hz |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
205.0mm (8.1") |
197.0mm (7.8") |
| Width |
1090.0mm (42.9") |
521.0mm (20.5") |
| Depth |
463.0mm (18.2") |
210.0mm (8.3") |
| Weight |
45.20kg (99.4lbs) |
8.45kg (18.6lbs) |
| Enclosure |
Bass Reflex |
Bass reflex |
| Finish |
n/a |
HDF |
| Available Colors |
High-Gloss White/Blue, High-Gloss White/Champagne, High-Gloss Black/ Grey, High-Gloss Black/Copper, Satin Walnut/Silver |
Black |
| Grille |
n/a |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
Yes |
Yes |
Other |
|
|
| Parts Warranty |
5 years |
5 Years |
| Labor Warranty |
5 years |
5 Years |
These sit in different price classes - KEF Reference 4 Meta costs roughly 26.8x 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 | evenly matched | Much the same reach (48Hz vs 50Hz). |
| Amplifier needs | evenly matched | Similar sensitivity (88dB vs 89dB) - both want much the same power. |
| Headroom | A | KEF Reference 4 Meta takes more power (400W vs 120W) - more in hand in a big room. |
| Size | depends | Emotiva Airmotiv C1+ is easier to place; KEF Reference 4 Meta is bigger, which usually goes with fuller bass. Your room decides. |
| Expandability | depends | KEF Reference 4 Meta: bi-amping; Emotiva Airmotiv C1+: bi-amping. Emotiva Airmotiv C1+ sits in a wider range (9 models), so a matched surround system is easier later. |
| Price | B | Emotiva Airmotiv C1+ is cheaper - $299 against $8,000, about 96% less; arguably a different class. |
A KEF Reference 4 Meta 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?
KEF Reference 4 Meta is ahead, but only on 1 of the measured areas, and it costs about 26.8x the price. That is a lot of money for a narrow margin on paper - Emotiva Airmotiv C1+ looks like the sensible buy unless something else about the KEF Reference 4 Meta appeals to you. Match it to your room: we rate KEF Reference 4 Meta the better fit for a large room and a very large room, and Emotiva Airmotiv C1+ for a small room and a mid-size room. In a large or open-plan room, KEF Reference 4 Meta has the cabinet volume to fill it more easily; in a small room, near a wall or at desk distance, Emotiva Airmotiv C1+ is the easier speaker to get right.
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.