In this review, we will be comparing Knight 3 and Knight 4, two Passive Floor-standing speakers by Castle.
Let's have a brief look at the main features
of Castle Knight 3 and Castle Knight 4 first before getting into our more
detailed comparison.
| Key Specs | Castle Knight 3 | Castle Knight 4 |
|---|
| Brand | Castle | Castle |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" Soft-Dome | 1" Soft-Dome |
|---|
| Woofer | 5" Natural Fibre | 2 x 5" Natural Fibre |
|---|
| Frequency response | 38-24k Hz | 36-24k Hz |
|---|
| Sensitivity | 88 dB | 90 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | 15-100 watts | 25-150 watts |
|---|
| Weight | 10.70kg / 23.5lbs | 12.50kg / 27.5lbs |
|---|
| Dimensions (H x W x D) | 32-5/16" x 6-1/2" x 10-7/16"
820.0 x 165.0 x 265.0mm | 35-7/16" x 6-1/2" x 10-5/8"
900.0 x 165.0 x 270.0mm |
|---|
Knight 3 and Knight 4 are members of Castle's Knight series of speakers. Below you can find the loudspeakers from this series.
Castle Knight Series
History
What size room are the Castle Knight 3 and Castle Knight 4 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 Knight 3 |
Castle Knight 4 |
| 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
Both Knight 3 and Knight 4 are 2-way speakers.
Castle Knight 3Castle Knight 4
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
Castle Knight 3 |
Castle Knight 4 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 5-inch
|
2 x 5-inch
|
Knight 3 features a 1" Textile Soft-Dome Tweeter and 1 x 5" Natural Fibre Woofer with a Crossover frequency at 3 kHz. On the other hand, the Knight 4 features a 1" Textile Soft-Dome Tweeter and 2 x 5" Natural Fibre Woofer with a Crossover frequency at 3 kHz.
Frequency Response
Knight 3 has a frequency range of 38-24k Hz whereas Knight 4 has a frequency range of 36-24k Hz. With a minimum frequency of 36Hz, the Knight 4 can go slightly deeper then the Knight 3's min frequency of 38Hz.
The graph below depicts how these two speakers compare with the max, min and average Low Frequency values of other speakers in the Floor-standing class in our database.
Low Frequency
Floor-standing 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
Knight 3 and Knight 4 have the same Impedance of 8 ohms but where they differ is the sensitivity levels. Knight 3 sensitivity is rated at 88 dB and the Knight 4's is at 90 dB. This 2 dB difference makes the Castle Knight 4 a more sensitive speaker compared to Castle Knight 3, hence will play louder with the same amount of watts.
Sensitivity
Floor-standing 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.
Knight 4 can handle a max power of 150 watts RMS, whereas Knight 3 has a max power handling value of 100 watts RMS, 50 watts less than the Knight 4.
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
Knight 3 features Binding post type posts and Knight 4 has a Binding post type posts. None of these speakers feature bi-amping/bi-wiring.
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 Knight 3's and Castle Knight 4's external dimensions. Castle Knight 3 has external dimensions of 820.0 x 165.0 x 265.0mm (32-5/16 x 6-1/2 x 10-7/16inch) whereas Castle Knight 4 has external dimensions of 900.0 x 165.0 x 270.0mm (35-7/16 x 6-1/2 x 10-5/8inch).
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. Castle Knight 4 is 80mm taller.
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 Knight 3 is approximately 437.3cm2 / 67.8inch2 and base area of the Castle Knight 4 is approximately 445.5cm2 / 69.1inch2. The Knight 3 requires 2% less surface area than the Knight 4 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 Castle Knight 3 weighs 10.70kg / 23.5lbs and the Castle Knight 4 weighs 12.50kg / 27.5lbs. This makes the Knight 4 17% heavier than the Knight 3.
Here is a comparison of how Knight 3 and Knight 4's weights compare with the average, max and min weights in Passive Floor-standing class.
Weight
All Floor-standing Speakers
 Height |
820mm
vs
900mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
437cm2
vs
445cm2
|
Takes less floor space |
 Max Input Power |
150 watts
vs
100 watts
|
Handle more power from your amplifier |
 Sensitivity |
90 dB
vs
88 dB
|
Play louder with same amount of amplification power |
 Number of Woofers |
2
vs
1
|
More woofers |
|
Low Frequency Response |
36 Hz
vs
38 Hz
|
Generates deeper bass |
| General |
Castle Knight 3 |
Castle Knight 4 |
| Brand |
Castle |
Castle |
| Speaker Type |
Floor-standing speaker |
Floor-standing speaker |
| Power Range |
15-100 watts |
25-150 watts |
| Sensitivity |
88 dB |
90 dB |
| Impedance |
8 ohms |
8 ohms |
| Frequency Response |
38-24k Hz |
36-24k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
2 |
| Woofer Size |
5" |
5" |
| Woofer Composition |
Natural Fibre |
Natural Fibre |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Soft-Dome |
Soft-Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
3 kHz |
3 kHz |
Physical Specs |
|
|
| Height |
820.0mm (32.3") |
900.0mm (35.4") |
| Width |
165.0mm (6.5") |
165.0mm (6.5") |
| Depth |
265.0mm (10.4") |
270.0mm (10.6") |
| Weight |
10.70kg (23.5lbs) |
12.50kg (27.5lbs) |
| Enclosure |
Transmission Line |
Transmission Line |
| Finish |
Real wood veneer, semi-matt lacquer |
Real wood veneer, semi-matt lacquer |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
|
|
| Labor Warranty |
|
|
Siblings in Castle's Knight series, so they share a family sound. It comes down to size, output and price.
| Area | Better | Why |
|---|
| Bass | evenly matched | Much the same reach (38Hz vs 36Hz). |
| Amplifier needs | B | Castle Knight 4 is more sensitive (90dB vs 88dB), so it goes louder on the same amplifier. |
| Headroom | B | Castle Knight 4 takes more power (150W vs 100W) - more in hand in a big room. |
| Size | depends | Similar cabinet size - neither is easier to fit. |
A Castle Knight 3 B Castle Knight 4
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?
Castle Knight 4 has the edge on paper, though the margin is not large. The rows marked "depends" may matter more to you than the score does. Match it to your room: we rate Castle Knight 3 the better fit for near-field listening and a small room, and Castle Knight 4 for a mid-size room and a large room. If your amplifier is modest, vintage or valve-based, Castle Knight 4 is the safer partner - the other will want more current or more watts to sound its best.
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.