Castle Windsor Earl vs KEF R3 Comparison

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Castle Windsor Earl

Passive Bookshelf | 58-22k Hz

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KEF R3

Passive Bookshelf | 52-28k Hz

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Castle Windsor Earl

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KEF R3

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Castle Windsor Earl

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KEF R3

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Castle Windsor Earl vs KEF R3 Speaker Comparison

In this review, we will be comparing Windsor Earl and R3, two Passive Bookshelf speakers from Castle and KEF.

Let's have a brief look at the main features of Castle Windsor Earl and KEF R3 first before getting into our more detailed comparison.

Key Specs	Castle Windsor Earl	KEF R3
Brand	Castle	KEF United Kingdom · founded 1961
Design	2-way	3-way
Uni-Q driver	—	12th Generation Uni-Q
Tweeter	1.1" Soft-Dome	1" Dome
Midrange	—	5"
Woofer	6.5" Woven Polypropylene	6.5" Hybrid aluminum
Frequency response	58-22k Hz	52-28k Hz
Sensitivity	89 dB	87 dB
Impedance	8 ohms	8 ohms
Power range	25-100 watts	15-180 watts
Weight	—	13.55kg / 29.8lbs
Dimensions (H x W x D)	16-15/16" x 9-7/16" x 10-1/4" 430.0 x 240.0 x 260.0mm	16-5/8" x 7-13/16" x 13-1/4" 423.0 x 199.0 x 337.0mm

What size room are the Castle Windsor Earl and KEF R3 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*	Castle Windsor Earl	KEF R3
Near-field	Average	Poor
Small Room	Good	Average
Mid-size Room	Average	Good
Large Room	Poor	Average
Very Large Room	Bad	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 Windsor Earl is a 2-way design whereas the R3 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.

Castle Windsor Earl

KEF R3

TweeterMidrangeWoofer

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

Driver	Castle Windsor Earl	KEF R3
Driver Setup	2-way	3-way
Tweeter	1.1-inch	1-inch
Midrange	-	1 x 5-inch
Woofer	1 x 6.5-inch	1 x 6.5-inch

Windsor Earl features a 1.1" Micro-Fibre Soft-Dome Tweeter and 1 x 6.5" Woven Polypropylene Woofer with a Crossover frequency at 2.2 kHz. On the other hand, the R3 features a 1" aluminum Dome Tweeter, a 5" Midrange and 1 x 6.5" Hybrid aluminum Woofer with a Crossover frequency at 400Hz and 2900Hz.

Frequency Response

Windsor Earl has a frequency range of 58-22k Hz whereas R3 has a frequency range of 52-28k Hz. With a minimum frequency of 52Hz, the R3 can go significantly deeper on the low side and provide stronger bass compared to the Windsor Earl's min frequency of 58Hz.

The graph below depicts how these two speakers compare with the max, min and average Low Frequency values of other speakers in the Bookshelf class in our database.

Low Frequency

Bookshelf Speakers

Windsor Earl

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

Windsor Earl and R3 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. Windsor Earl sensitivity is rated at 89 dB and the R3's is at 87 dB. This 2 dB difference makes the Castle Windsor Earl a more sensitive speaker compared to KEF R3, hence will play louder with the same amount of watts.

Sensitivity

Bookshelf Speakers

Windsor Earl

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.

R3 can handle a max power of 180 watts RMS, whereas Windsor Earl has a max power handling value of 100 watts RMS, 80 watts less than the R3.

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

Castle Windsor Earl

KEF R3

Input Type and Bi-Amping / Bi-Wiring

R3 features Binding post posts which make bi-amping or bi-wiring possible. Windsor Earl has a Binding post which doesn't feature bi-amping/bi-wiring.

Cabinet Type and Port Position

Both Windsor Earl and R3 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.

KEF R3 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 Castle Windsor Earl's and KEF R3's external dimensions. Castle Windsor Earl has external dimensions of 430.0 x 240.0 x 260.0mm (16-15/16 x 9-7/16 x 10-1/4inch) whereas KEF R3 has external dimensions of 423.0 x 199.0 x 337.0mm (16-5/8 x 7-13/16 x 13-1/4inch).

KEF R3 is 41mm narrower and 7mm shorter than Castle Windsor Earl but it is also 77mm 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.

Near-identical footprints. KEF R3 is 77mm 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 Castle Windsor Earl is approximately 624.0cm² / 96.7inch² and base area of the KEF R3 is approximately 670.6cm² / 103.9inch². The Windsor Earl requires 7% less surface area than the R3 which gives it a small advantage on placement in tight spaces.

What's in the Box of KEF R3?

Here are the items that come with the R3:

2 Bookshelf loudspeakers
2 Grilles
2 Foam port plugs
8 Self-adhesive rubber feet
User Manual
Warranty Information

Reasons to choose Castle Windsor Earl over KEF R3

Sensitivity	89 dB vs 87 dB	Play louder with same amount of amplification power
Minimum Impedance	4.3 ohms vs 3.2 ohms	Very low impedance levels puts more pressure on amplifier
Base Surface Area	624cm² vs 670cm²	Takes less floor space

Reasons to choose KEF R3 over Castle Windsor Earl

Max Input Power	180 watts vs 100 watts	Handle more power from your amplifier
Driver Setup	3-way vs 2-way	Have a dedicated mid-range driver
Low Frequency Response	52 Hz vs 58 Hz	Generates deeper bass
High Frequency Response	28k Hz vs 22k Hz	Generates higher frequency
Height	423mm vs 430mm	Easier to fit in smaller spaces
Price per pair*	2200USD vs 5250USD	costs less (*prices may change depending on the seller, location and time)

Castle Windsor Earl vs KEF R3 Specs Table

Detailed comparison of specifications

General	Castle Windsor Earl	KEF R3
Brand	Castle	KEF
Speaker Type	Bookshelf speakers	Bookshelf speakers
Power Range	25-100 watts	15-180 watts
Sensitivity	89 dB	87 dB
Impedance	8 ohms	8 ohms
Impedance	4.3 ohms	3.2 ohms
Frequency Response	58-22k Hz	52-28k Hz
Drivers
Woofer Quantity	1	1
Woofer Size	6.5"	6.5"
Woofer Composition	Woven Polypropylene	Hybrid aluminum
Woofer Surround Material	n/a	Rubber
Tweeter Size	1.1"	1"
Tweeter Type	Soft-Dome	Dome
Aimable Tweeter	No	No
Midrange Driver	No	5"
Crossover Frequency	2.2 kHz	400Hz and 2900Hz
Firing Direction	rear	rear
Physical Specs
Height	430.0mm (16.9")	423.0mm (16.7")
Width	240.0mm (9.4")	199.0mm (7.8")
Depth	260.0mm (10.2")	337.0mm (13.3")
Weight	n/a	13.55kg (29.8lbs)
Enclosure	Bass Reflex	Bass Reflex
Finish	Walnut veneer, Mahogany veneer	MDF/Lacquer
Available Colors	n/a	Black Gloss, White Gloss, Walnut
Mounting Bracket		No
Grille	n/a	Yes
Moisture Resistancy	No	No
Connections
Biamp Inputs	n/a	Yes
Other
Parts Warranty		5 Years
Labor Warranty		5 Years

Verdict

These sit in different price classes - Castle Windsor Earl costs roughly 2.4x what KEF R3 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	KEF R3 digs deeper - 52Hz against 58Hz. A subwoofer would even that out.
Amplifier needs	A	Castle Windsor Earl is more sensitive (89dB vs 87dB), so it goes louder on the same amplifier.
Headroom	B	KEF R3 takes more power (180W vs 100W) - more in hand in a big room.
Size	depends	Similar cabinet size - neither is easier to fit.
Expandability	B	KEF R3: bi-amping. KEF R3 sits in a wider range (5 models), so a matched surround system is easier later.
Price	B	KEF R3 is cheaper - $2,200 against $5,250, about 58% less; arguably a different class.

A Castle Windsor Earl B KEF R3
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 R3 is the easier recommendation: it leads on most of the measured areas and costs less. Take Castle Windsor Earl if its size, looks or fit in your room suit you better. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 58Hz anyway, so judge these on the other rows instead. Match it to your room: we rate Castle Windsor Earl the better fit for near-field listening and a small room, and KEF R3 for a mid-size room and a large room.

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.