Preliminary information

The main idea was to build  prestigious two way floor standing loudspeaker that, like other N.N. Acoustics models, offered the listener a unique experience of listening to the music rather than the loudspeakers.

K2 had to be as neutral as possible, devoid of the tiniest colorations in the whole bandwidth, extremely accurate, of superb dynamics, perfectly resolute and transparent. Namely, there could be nothing added or taken from the original information.

The horizontal and especially vertical dispersion of sound in the full bandwidth had to be wide enough to allow the listener to listen from any position in the room. This feature is crucial for highest quality sound reproduction. The appearance had to be powerful, yet likable and elegant.

In N.N. Acoustics line of products this model should be between the models Rubycon and Masterpiece.

The Cabinet

When it came to the design of the wooden cabinet, there was no doubt whatsoever. Only the best acoustic construction made of top quality natural materials would do. The cabinet had to be as sturdy and as non resonant as possible. The resonance that couldn’t be eliminated had to be shifted towards the higher frequency range, away from the working range of the mid-bass speaker.

Only a V shaped cabinet, made by putting together segments of premium class beech plywood, could guarantee the feasibility of this idea. What I came up with was a very solid, rigid, oval cabinet. Other solutions, similar to this one only by the appearance, are based upon ready made curved panels that use up a little more material than the classic parallelepiped shape. Speaking from the acoustics point of view, this shape is better than flat surface, but still not as good as the solution that N.N.Acoustics uses. The quantity of the material used for such a segmented construction is several times larger compared to the classic solutions.

To obtain the perfect shape only manual sanding of the glued segments was applicable, using the massive sled weighing 50 kg, custom made for this model.

As with other N.N.Acoustics models, the bracing and especially the CERARD structure take additional resonance from the cabinet. The overall thickness of the baffle is 90 mm while the sides are from 67 mm to 80 mm thick. A very good distribution of the inner volume has been achieved while the outer shape prevents the reflection of sound waves inevitable in the case of cabinets with sharp edges.

At the bottom of the cabinet there is a special compartment that contains the passive cross-over as with the model Masterpiece. This way the elements of the passive cross-over have been protected against the smallest interference of the vibrations and magnetic field of the mid-bass speaker and ribbon unit.

The Finish

The cabinet is finished with exotic Indian palisander veneer that has been carefully chosen, mached, laid out and glued together by hand. Eight coats of highest quality oils and waxes have been applied for finish and protection. The plinth of the cabinet is painted with a special black matte paint. You can put a special order for a black granite base.

Bass-reflex

In order to optimize performance of model K2 according to the room and personal taste of the user, the bass reflex tube has adjustable length. The tube has curved in and out openings to prevent formation of noise caused by air passing through.

Loudspeaker Units

There was only one possible choice of the tweeter unit – the custom made RAAL true ribbon. Basically, the tweeters that operate on other principles sound dull, blurred, and lifeless, with not enough details and without that precious airiness of the sound. Other ribbon speakers are too directed in the vertical plane, thus leaving the listener with a listening spot instead of a listening area.

When it came to the point when this amazing true ribbon had to be paired with an adequate partner for the lower frequency range I realized that no commercially obtainable 8 inch mid-bass component could meet all the requirements. I finally decided upon custom made 8 inch AUDIO TECHNOLOGY unit. It had the accuracy, neutralness, transparency, resolution, long excursion, above average efficiency, very small distortion and excellent dynamic capability.

Cross-over

The elements of the passive cross-overs are of the highest possible quality as well, firmly wired, strictly matched and with tolerances below 0.5 %.

Polypropylene capacitors have extremely low ESR.

To eliminate vibrations that form in air-core coils due to passing of the signal, the coils have been treated with special resin and heated until complete hardening of the resin. The coil form is ABS; copper round wire of 99.99% purity has been used.

Resistors are non ceramic, non inductive, formed in the high power groups in order to eliminate heating when system is working on high load and achieve an exact value.