Reference 4c - Loudspeaker KEF - Free user manual and instructions

Product Type	Floorstanding Loudspeaker
Brand	KEF
Model	Reference 4c
Dimensions (H x W x D)	350 mm x 180 mm x 250 mm
Weight	7.5 kg (16.5 lbs)
Power Handling	10 - 100 W
Frequency Response	60 Hz - 40 kHz
Impedance	8 ohms
Sensitivity	86 dB (2.83V/1m)
Driver	4.5-inch Uni-Q driver array
Crossover Frequency	2.5 kHz
Recommended Amplifier	10 - 100 W per channel
Input Type	Single-wire binding posts
Finish	Available in piano black, white, or walnut
Main Features	Uni-Q driver for wide dispersion, low distortion, and high clarity
Cleaning	Dust with a soft, lint-free cloth. Do not use any solvents or cleaners.
Safety	Place on a stable surface. Avoid exposure to moisture, direct sunlight, or extreme temperatures.
Spare Parts & Repairability	Contact an authorized KEF service center for any repairs or spare parts.

Frequently Asked Questions - Reference 4c KEF

How do I connect my KEF Reference 4c speakers?

Use high-quality speaker wire with banana plugs or bare wire. Connect the positive terminal of your amplifier to the red binding post, and the negative to the black. Ensure a secure connection.

Can I bi-wire or bi-amp the Reference 4c?

The Reference 4c has single-wire binding posts, so bi-wiring or bi-amping is not supported. Use a single high-quality cable.

What is the recommended placement for the Reference 4c?

Place speakers at ear level when seated, at least 1 foot (30 cm) from walls. For optimal imaging, angle them slightly toward the listening position.

Is there a break-in period for these speakers?

Yes, allow 20-50 hours of play at moderate volume for the drivers to reach their optimal performance.

What amplifier power is recommended?

Use an amplifier with power between 10 and 100 watts per channel. Avoid underpowered amps that may clip and damage the speakers.

How do I clean my KEF Reference 4c speakers?

Use a dry, lint-free cloth to wipe the cabinet and driver grille. Do not use any liquids or abrasive cleaners.

What should I do if there is no sound from the speakers?

Check all connections (speaker wire, amplifier source). Ensure the amplifier is turned on and not muted. Verify that the speaker wire is not shorting.

Does the Reference 4c come with a warranty?

Yes, KEF offers a 5-year limited warranty for the Reference series. Retain your original receipt.

Can I use these speakers for home theater?

Yes, they work well as front left/right or surround speakers. Pair with a center channel and subwoofer for optimal surround sound.

What are the exact specifications of the Reference 4c?

Refer to the user manual. Key specs: 4.5-inch Uni-Q driver, frequency response 60Hz-40kHz, sensitivity 86dB, impedance 8 ohms, power handling 10-100W.

USER MANUAL Reference 4c KEF

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Now with Metamaterial Absorption Technology

The Reference has continually set the benchmark for loudspeakers since its launch in 1973. The perfect reproduction of recorded sound is what The Reference has always stood for. Pioneering the use of digital technologies to achieve the highest audio accuracy, every pair of The Reference series can be matched within half a decibel to the laboratory-maintained reference standard. Exact pair matching delivers perfect stereo reproduction, so these revolutionary speakers won acclaim for the superior acoustic precision. Hence the method became the name: The Reference.

Since the first generation, The Reference has been continuously enhanced by new innovations and technological developments. In the latest evolution, The Reference incorporates our latest innovation: Metamaterial Absorption Technology ^1 (MAT ^™ ) and continues to be the supreme expression of KEF's philosophy, where advanced engineering meets inspired design.

The Reference are loudspeakers for serious audiophiles who aspire to the perfect enjoyment of music and movies. Whether used in a traditional two-channel HiFi or a multi-channel home theatre, listeners will be able to experience the realistic, immersive sound with breath-taking dynamics, and levels of accuracy that reveal details never noticed before.

A class apart

The Reference range encompasses two three-way floorstanding speakers, a formidable three-way standmount speaker, and two three-way centre speakers that can be used as Left-Centre-Right (LCR) speakers. The Reference combines phenomenal high-fidelity performance with complete multi-channel versatility.

And now new technological advances make The Reference range even more impressive. At the heart of The Reference range now sits a bespoke 12 ^th generation Uni-Q with MAT driver array. This new addition truly puts The Reference range in a class of its own.

Revolutionary sound absorption with MAT™

A truly revolutionary tool in the KEF acoustic armoury, Metamaterial Absorption Technology (MAT) is a highly complex maze-like structure, where each of the intricate channels efficiently absorbs a specific frequency. When combined, the channels act as an acoustic black hole, absorbing 99% of the unwanted sound that comes from the rear of the tweeter, eliminating the resulting distortion and providing a purer, more natural acoustic performance.

A result of joint development with the Acoustic Metamaterials Group, using MAT breaks completely new ground in loudspeaker design, and once again demonstrates KEF's unrelenting passion for developing new technologies to improve your listening experience. Metamaterials are specially developed structures that use existing materials in such a way that they exhibit new, desirable properties that are simply not found in naturally occurring substances.

12 ^th Generation Uni-Q with MAT ^™ delivers

The 12^th generation Uni-Q with MAT in The Reference is a bespoke driver array engineered to deliver pristine performance across this exceptional range of loudspeakers. It's the result of decades of accumulated in-house knowledge and the application of cutting-edge simulation and analysis tools. The developments are many and all play a part in The Reference's pristine performance.

As a starting point, KEF engineers re-engineered the tweeter gap damper to maximise the space at the back of the tweeter for the new metamaterial absorber. Optimising the cavity shape and strategically placing two rings of porous material effectively tame the resonances and imperfections, thus greatly improving detail and clarity.

A new ultra-low distortion midrange motor design uses a copper ring embedded into the motor gap to minimise inductance and variation of inductance with coil position. This lowers the midrange THD and reduces thermal compression, leading to improved efficiency.

The Uni-Q driver array is fully decoupled to prevent unwanted vibrations from muddying the sound. A new flexible decoupling chassis is designed to reduce vibration and remove coloration. It ensures that any vibration generated by the mid and high-frequency motor system is not transmitted to the loudspeaker cabinet.

Summary of features

• Metamaterial Absorption Technology eliminates 99% of high-frequency distortion for pure, natural sound
• Bespoke 12^th generation Uni-Q with MAT driver array for exceptional acoustic accuracy
• Enhanced crossover design fine-tuned the signal path for maximum clarity
• Optimised cabinet design for best acoustic performance
• Five models: Reference 1 Meta, Reference 3 Meta, Reference 5 Meta, Reference 2 Meta, Reference 4 Meta
  • Available in 5 finishes
• With mounting inserts to secure on KEF S-RF1 Floor Stand (available as separate item)
• The Reference Series Grille set for each model is available as separate item

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A new driver surround is designed to allow longer excursion without causing diffraction and extending the frequency range of the mid-frequency. Plus, the contours of the dome, midrange horn and surround are all computer-optimised to ensure a perfectly smooth transition to the cabinet.

KEF's patented tangerine waveguide technology manages the airflow to recreate the wide, even spread of a natural sound field, dispersing the astonishingly pure high-frequency imaging throughout the room.

The result of these innovations and developments is that this bespoke 12^th generation Uni-Q with MAT offers a sound that is more transparent and life-like than previously possible.

Reference quality bass

High and mid-range frequencies are only part of the story though, and The Reference is also blessed with clean, rich, highly articulate bass. That's because The Reference's 165mm (6.5 inch) low frequency driver perfectly complements the new 12^th generation Uni-Q with MAT driver array. Smart engineering and meticulous attention to design detail enables the bass to blend seamlessly with the immaculate midrange and treble response.

The Reference's bass driver also benefits from a massive, vented magnet assembly, a large aluminium voice coil and an exceptionally light and stiff alloy cone. As a result of all these technologies volume, dynamics and power handling are superb.

Engineered to be flexible

The speakers in The Reference range are also welcomingly undemanding in terms of positioning, and are easy to fine-tune for your listening area by using KEF's innovative Flexible Port Technology, which can reduce port resonance. There are two options of port tubes, allowing users to modify the sound to suit their room. Plus, the flare and profile of each port has been calculated by computational fluid dynamics to avoid turbulent air noise that might colour the sound, another part of the complex jigsaw that is The Reference's breath-taking performance.

Total attention to detail

Every speaker in The Reference range exudes the sense of sheer quality that comes from being hand-built by KEF's master craftsmen in Maidstone, Kent, UK. They are designed to be acoustically exceptional, attractive to look at, and each speaker is meticulously built to KEF's exceptional standards.

All the cabinets are designed using finite element analysis to determine the ideal shape and bracing geometry to minimise secondary radiation from the sides, with Constrained Layer Damping applied to turn what little vibration is left into heat.

Furthermore, the expertly engineered cabinets are finished in a sumptuous high-gloss or richly detailed, pair-matched wood veneers to complement the strikingly distinctive front baffle, which is designed to eliminate anomalies caused by diffraction. Five finishes are available, a combination of three cabinet finishes and five drive unit colours: Satin Walnut/Silver, High-Gloss White/Blue, High-Gloss White/Champagne, High-Gloss Black/Grey, High-Gloss Black/Copper.

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Satin Walnut/ Silver

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High-Gloss White/Blue

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High-Gloss White/Champagne

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High-Gloss Black/Grey

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High-Gloss Black/Copper

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Specifications

Model	REFERENCE 1 Meta REFERENCE 3 Meta REFERENCE 5 Meta
Design	Three-way bass ref lex Three-way bass ref lex Three-way bass ref lex
Drive units	Uni-Q driver array:HF: 25 mm (1 in.) aluminium dome with MATMF: 125 mm (5 in.) aluminium coneBass units:LF: 165 mm (6.5 in.) aluminium cone	Uni-Q driver array:HF: 25 mm (1 in.) aluminium dome with MATMF: 125 mm (5 in.) aluminium coneBass units:LF: 2 x 165 mm (6.5 in.) aluminium cone	Uni-Q driver array:HF: 25 mm (1 in.) aluminium dome with MATMF: 125 mm (5 in.) aluminium coneBass units:LF: 4 x 165 mm (6.5 in.) aluminium cone
Frequency range free field (-6dB)	Short port: 40 Hz - 45 kHzLong port: 37 Hz - 45 kHz	Short port: 38 Hz - 45 kHzLong port: 35 Hz - 45 kHz	Short port: 35 Hz - 45 kHzLong port: 32 Hz - 45 kHz
Frequency range typical in room bass response (-6dB)	30 Hz 28 Hz 25 Hz
Frequency response (±3dB)	45 Hz - 35 kHz 43 Hz - 35 kHz 40 Hz - 35 kHz
Crossover frequency	450 Hz, 2.1 kHz 450 Hz, 2.1 kHz 450 Hz, 2.1 kHz
Amplifier requirements	50 - 200 W 50 - 300 W 50 - 400 W
Sensit ivity (2.83V/ 1m)	85 dB 86 dB 88 dB
Harmonicdistortion 2^nd & 3^rd harmonics (90dB, 1m)	<0.5% 40 Hz - 100 kHz<0.2% 200 Hz - 2 kHz<0.1% 2 kHz - 20 kHz	<0.5% 40 Hz - 100 kHz<0.2% 200 Hz - 2 kHz<0.1% 2 kHz - 20 kHz	<0.5% 40 Hz - 100 kHz<0.2% 200 Hz - 2 kHz<0.1% 2 kHz - 20 kHz
Maximum output (peak sound pressure level at 1m with pink noise)	111 dB	113.5 dB	116 dB
Impedance	4 Ω (min. 3.2 Ω)	4 Ω (min. 3.2 Ω)	4 Ω (min. 3.2 Ω)
Weight	18.2 kg (40.1 lbs.)	51.3 kg (113.1 lbs.)	60.2 kg (132.7 lbs.)
Dimensions (H x W x D)(with grille and terminal)	440 x 205 x 422 mm(17.3 x 8.1 x 16.6 in.)	1155 x 205 x 462 mm(45.5 x 8.1 x 18.2 in.)	1350 x 205 x 462 mm(53.1 x 8.1 x 18.2 in.)
Dimensions (H x W x D)(with grille, terminal & plinth)	N/A	1207 x 323 x 467 mm(47.5 x 12.7 x 18.4 in.)	1402 x 323 x 467 mm(55.2 x 12.7 x 18.4 in.)
Standard finishes	Satin Walnut/Silver, High-Gloss White/Blue, High-Gloss White/Champagne, High-Gloss Black/Grey, High-Gloss Black/Copper

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Model REFERENCE 2 Meta REFERENCE 4 Meta

Design Three-way closed box Three-way bass ref lex
Drive units Uni-Q driver array:	HF: 25 mm (1 in.) aluminium dome with MAT	Uni-Q driver array:
	MF: 125 mm (5 in.) aluminium cone	HF: 25 mm (1 in.) aluminium dome with MAT
	Bass units:	MF: 125 mm (5 in.) aluminium cone
	LF: 2 x 165 mm (6.5 in.) aluminium cone	Bass units:
		LF: 4 x 165 mm (6.5 in.) aluminium cone
Frequency range free field (-6dB) 65 Hz - 45 kHz Short port: 43 Hz - 45 kHz		Long port: 40 Hz - 45 kHz
Frequency range typical in room bass response (-6dB)	46 Hz 33 Hz
Frequency response (±3dB) 80 Hz - 35 kHz 48 Hz - 35 kHz
Crossover frequency 450 Hz, 2.1 kHz 450 Hz, 2.1 kHz
Amplifier requirements 50 - 300 W	50 - 400 W
Sensitivity (2.83V/ 1m) 86 dB 88 dB
Harmonic distortion	<0.5% 40 Hz - 100 kHz	<0.5% 40 Hz - 100 kHz
2nd & 3rd harmonics (90dB, 1m)	<0.2% 200 Hz - 2 kHz	<0.2% 200 Hz - 2 kHz
	<0.1% 2 kHz - 20 kHz	<0.1% 2 kHz - 20 kHz
Maximum output (peak sound pressure level at 1m with pink noise)	113.5 dB	116 dB
Impedance	4 Ω(min. 3.2 Ω)	4 Ω(min. 3.2 Ω)
Weight	22.8 kg (50.3 lbs.)	45.2 kg (99.6 lbs.)
Dimensions (H x W x D)(with grille and terminal)	205 x 630 x 335 mm(8.1 x 24.8 x 13.2 in.)	205 x 1090 x 463 mm(8.1 x 42.9 x 18.2 in.)
Dimensions (H x W x D)(with grille, terminal & plinth)	N/A	N/A
Standard finishes	Satin Walnut/Silver, High-Gloss White/Blue, High-Gloss White/Champagne, High-Gloss Black/Grey, High-Gloss Black/Copper