Castle Knight 5, The return of the knight

Many years ago (about 30, more or less) it was very difficult to find loudspeakers of any quality in Spain, and putting together a decent hi-fi system was really complicated. You could see models from Pioneer, JBL, a few enterprising manufacturers from our own country… and a British brand that everyone raved about. It was called Castle. At that time, it was the absolute benchmark for everything that high-end sound represented. People even spoke of the "Castle Sound", a term that has been revived with this relaunch, since IAG has said that this character would be respected.

Time has passed: Castle disappeared from circulation in the face of the flood of quality brands that arrived and remained in the wilderness for some years. Now IAG has revived the brand, and when Juan Pablo, manager of Reydis, its distributor in Spain, asked me whether I wanted to test the brand-new Knight 5, I couldn't help remembering those very hard times for lovers of high-end sound. The range of products we have to choose from now is enormous, and we can try out any equipment at any specialist dealer. The landscape in our country has undoubtedly improved a great deal, but we have to keep fighting to keep making progress.

Having got over my attack of nostalgia, let's focus on our guests. They are the top of the range of the British company's new Knight series (although the brand belongs to China's IAG, we will call them British, since the design work is done in the United Kingdom).

DESIGN AND CONFIGURATION

Externally, the loudspeakers have a fairly traditional design with straight lines. They have a very special two-way configuration. The factory specifications list them as floor t-line, that is, transmission-line loudspeakers (see accompanying sidebar), although I would actually describe them as a new way of building loudspeakers of this type. The Knight 5 incorporates Castle's patented TPT (Twin-Pipe Technology), which improves the bass performance of floorstanders by using the internal volume of the cabinet, extending the response of the lowest tones and avoiding the problems inherent to bass-reflex designs or, rather, the complications that getting them to work correctly always entails, depending on their placement and design. In fact, according to the manual, our guests can reach down to the far from negligible figure of 30 Hz.

The loudspeaker consists of a 25 mm tweeter and two 150 mm fiber-cone bass drivers. At the bottom there is an opening, as is usual in transmission-line loudspeakers (although it is sometimes at the rear), which may surprise those less familiar with the subject. The binding posts, prepared for bi-wiring, are of acceptable quality and accept spades and bananas as well as bare wire. The loudspeakers can be used on decoupling spikes, on a plinth or directly on the floor, depending on the surface.

As is usual at IAG, value for money has been the priority, and this shows in small details, such as the aforementioned binding posts or the quality of the varnish, which, while good, is not extraordinary.

PUT TO THE TEST

The loudspeakers arrived brand new, so I had to leave them running for about 72 hours for the sound to reach the right point for a proper assessment. But as soon as they started playing, I was surprised by the smoothness of the music, when the opposite is usually the case. Normally, loudspeakers that have not been run in tend to sound somewhat metallic, with subdued bass.

For this Lab review I used the familiar Marantz PM7003 and a NAD C545BEE CD player, with VandenHul interconnects and speaker cables. Since there is no need to think about the waves bass-reflex ports may generate, placement is quite simple, as the distances from the side or rear walls do not need to be controlled so closely. However, all loudspeakers without exception always need some breathing room to give their best. And the Knight 5 is no exception. Since the room had a carpeted floor, I placed the loudspeakers without a plinth or decoupling spikes. After some testing, it seemed to me that this gave the best sound. Better results are also obtained (always depending on the room) by angling the loudspeakers about 30º toward the listening position, as this widens the sweet spot (which we could translate as the ideal listening area). In a strictly forward-facing configuration, I noticed that this area shrank considerably.

For the first tests I used Van Morrison's wonderful Back on top, a superb recording featuring a wide variety of instruments and even a small string ensemble, ideal for testing loudspeakers. I won't deny that, after so many years, I too was looking for the Castle sound, and I found it… halfway. Basically, it was based on two principles the manufacturer proudly boasted of: neutrality and detail. The second remains excellent, full of nuance and with a high level of transparency. But the neutrality is no longer what it was, nor is Castle's current positioning compared with the past. The loudspeakers have a certain brightness and a minimal amount of coloration, which departs from the extreme linearity I heard in other Castle models. With a product made and designed to be sold at affordable prices, the necessary concessions take their toll in the form of the ever-undesirable coloration of the sound. In short, my listening left me with the impression that the British company has made a small attempt to popularize its loudspeakers, making them suitable for less experienced ears or for those who prefer other kinds of loudspeakers. The biggest surprise with these Castles, however, comes from their fantastic bass response: extended, detailed, deep and without any kind of excess. In this respect the improvement has been spectacular, because even with very marked changes in dynamics in the voice of the old Belfast lion, the bass response was lightning fast. I noticed no distortion or blurring, even when playing at considerable sound pressure levels.

The soundstage is wide and instrument placement is good, although if we move a little we will notice obvious differences in the sound, revealing a somewhat small "sweet spot".

I continued with Martha Argerich's wonderful recording of Tchaikovsky's Piano Concerto No. 1 and Rachmaninov's No. 3 for Philips. The Argentine artist's piano sounded transparent and very detailed to me, but I liked the compact, expansive sound of the orchestra even more, with overwhelming dynamics. Once again, the best thing was the bass and, in this particular case, I noticed a slight predominance of the midrange, although not excessive. I think the tweeter is a step below the bass, since on careful listening the highs are a little dark, or perhaps the transmission-line configuration favors the bass (certainly) and penalizes the higher tones (unlikely). Perhaps with a somewhat better tweeter the performance would have been extraordinary but, as it is, the loudspeakers leave me with the impression of being slightly unbalanced.

Since I had the Electrocompaniet ECI 5 MKII in the test room, I decided to continue the assessment with that amplifier, to see whether I noticed any aspects or nuances that had escaped me. In this case, what I obtained was a wider soundstage, which expanded considerably, and much more precise instrument placement.

CONCLUSION

It has been a joy for me to see that Castle is back, and I hope it is here to stay. I was also very pleased that the new Knight series includes transmission-line models. Focusing on the Knight 5 specifically, by far the most remarkable things have been the magnificent bass response, the good level of detail and the transparency. Without forgetting the coloration already mentioned, the extraordinary value for money they offer must be stressed. It is very difficult to find loudspeakers of this level for €1,000 (999, to be exact). Even less so when they are transmission-line loudspeakers. I don't usually make categorical statements, but I would venture to say that there is practically no loudspeaker on the market with this configuration at that price. We may question IAG's policy of repositioning a classic top-tier brand in the popular price segment at the cost of the concessions that are logical in such cases. But the truth is that IAG has added one more competitor to the area of the market where quality is a step above. These Castles are a magnificent way to start cultivating this hobby, enjoying our favorite recordings without excessive investment. And, in this sense, IAG's policy of bringing products of this kind and at these prices to market is to be welcomed.

WE LIKE

Value for money.

Bass response.

Level of detail.

COULD BE IMPROVED

Balance.

Tweeter.

Slight coloration.

Specialists' rating: 5

The principle behind this configuration is based on the property that there is no resonance in pipes, but in this case the wave generated by the rear of the diaphragm is indeed put to use. It helps reinforce the low frequencies by bringing the rear and front waves of the diaphragm into phase. In the case of these loudspeakers, they came with a small block of foam to attenuate the bass, which in my tests was perfectly adjusted. However, depending on each listener's taste, the amount of foam can be increased, thus reducing the internal volume of the cabinet and consequently the bass response. Practically like a tailor-made suit.

Castle Knight 5, The return of the knight

Specifications

RECOMMENDED AMPLIFICATION 25 – 200W.

NOMINAL IMPEDANCE 8 Ohms.

SENSITIVITY 90 dB.

FREQUENCY RESPONSE 30 Hz – 24kHz.

DIMENSIONS 925 x 200 x 335 mm. WEIGHT 20 Kg.

DISTRIBUTOR Reydis (951441010).