UNITRA ZGB-401-B Bookshelf speakers with bass-reflex, black ash

Modern sound in a classic form

ZGB-401 is a compact speaker system with a bass-reflex construction, designed specifically for bookshelf speaker enthusiasts. Equipped with an advanced 2-way system utilizing a precise crossover, it ensures a linear sound characteristic, providing faithful reproduction of musical material. The high-frequency transducer, thanks to its innovative design, improves directivity, while the aluminum-ceramic membrane of the low-midrange transducer ensures high rigidity with minimal mass. The bass-reflex port plug facilitates system adaptation to various acoustic conditions. High-quality components, such as air coils and metalized polypropylene capacitors, ensure a linear transfer characteristic without visible divisions in the frequency range. The finish with natural materials, including wooden veneer and Polish linen, gives the system an aesthetic appearance. ZGB-401 collaborates seamlessly with a wide range of amplifiers, making it a universal solution for discerning audiophiles.

Bass-reflex construction

Our solution employs a well-known bass-reflex enclosure design with a tuned port. The low-midrange section is handled by a 6-inch transducer featuring a very light and rigid aluminum-ceramic membrane, characterized by very low distortions. Meanwhile, in the upper part of the acoustic range, an aluminum-magnesium dome with a unique construction improves directional characteristics. This configuration allows for enjoying a coherent, full sound that is reproduced over a broad spatial range beyond the main axis of the speakers.

The system is also adaptable to function as a closed enclosure. This is facilitated by the included bass-reflex port plug, allowing the speakers to be adapted to smaller or acoustically challenging spaces and specific placement conditions.

Advanced 3rd Order Crossover

The use of an advanced 3rd-order passive crossover enables a proper and optimal division of the audio signal frequency ranges between the speakers. This maximizes the utilization of their best characteristics while simultaneously eliminating negative interferences. The high attenuation of the filters also helps to reduce distortions, especially those characteristic of a high-frequency aluminum dome operating outside its optimal frequency range. The crossover is designed in a way that achieves the most linear processing characteristic without excessively highlighting the extremes of the frequency spectrum, aiming to faithfully reproduce recordings. We have employed top-quality components, including air coils and metalized polypropylene capacitors, which enhance the linearity of the transfer characteristic without visible divisions in the frequency range.

Smooth impedance characteristics

Smooth impedance characteristics with no local low extremes, making it possible to connect to amplifiers sensitive to changes in load impedance.

Double box design

The design of the enclosure is based on an uncommon on the market "box-in-box" arrangement for greater rigidity of the structure. The resulting weight of the set of more than 70 kg has a significant impact on the reduction of vibrations of the enclosure walls and parasitic resonances generated as a result, which positively translates into sound quality.

Finishing with natural materials

The enclosures are finished with natural wood veneer made from selected leaves and hand oiled. In addition to the standard black grilles, we also have more classic ones, for which we used Polish linen.