Unitra was a Polish manufacturer of consumer electronics, specializing in audio equipment such as radios, tape recorders, and amplifiers.

Unitra

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The ZGB-401 Speaker set from Unitra is a powerhouse of sound neatly packed into a bass-reflex bookshelf speaker design. Made to enthuse both novices and audiophiles alike, these speakers integrate closed construction dynamics with a bass-reflex system, tailored to enhance audio performance. The high and low-midrange transducers selected are known for their efficiency and contribute to the system's ability to produce clear, dynamic, and effective sound outcomes. These speakers can be effortlessly paired with various amplifiers which makes them a highly versatile addition to any audio system setup.

Priced at PLN 12,499, the ZGB-401 speakers offer modern sound in a classic form. This compact system is highlighted by its advanced 2-way system with a precise crossover that promises a linear sound characteristic, ensuring faithful reproduction of musical material. The cutting-edge design also encompasses a high-frequency transducer and an aluminum-ceramic membrane for the low-midrange transducer, enhancing the rigidity and reducing mass. The inclusion of a bass-reflex port plug facilitates adjustments to different acoustic conditions, ensuring high-quality sound in variably sized spaces.

The speakers use a well-regarded bass-reflex enclosure design, featuring a tuned port and a 6-inch transducer with an aluminum-ceramic membrane for minimal distortions. The aluminum-magnesium dome of the tweeter improves the directional characteristics, offering a broad and coherent sound reproduction. For acoustic versatility, the design accommodates a bass-reflex port plug, enabling modifications suitable for smaller or challenging acoustic environments.

Intricate crossovers are part of its design; an advanced 3rd-order passive crossover helps optimize frequency division between the speakers, maximizing their performance and minimizing interferences. This is done using premium components including air coils and metalized polypropylene capacitors that sustain a consistent characteristic across the frequency range. The design also ensures a smooth impedance characteristic, accommodating amplifiers with sensitivity to load impedance changes.

Its exceptional double box design enhances structural rigidity, significantly reducing vibrations and parasitic resonances, which in turn, refines the audio quality. The natural wood veneer finish, available in finishes like Black Ash or American Walnut, and optional grilles in standard black or Polish linen, further accentuates its sophisticated appearance.

**Product specifications are as follows:**
- Frequency Response: 60Hz - 23kHz
- Sensitivity: 87 dB
- Impedance: 4 Ω (minimum 3.5Ω)
- Power Rating: 60W RMS
- System: 2-way
- Crossover Frequencies: 700 Hz / 2.4 kHz
- Enclosure Type: Bass-reflex (with port plug)
- Connector Type: Dual (bi-wire / bi-amp)
- Tweeter: 27 mm aluminum-magnesium
- Midwoofer: 6” aluminum-ceramic
- Dimensions (H x W x D): 380 x 210 x 280 mm
- Weight: 2 x 10.5 kg
- Grille: Black acoustic fabric or natural linen
- Finishes: Real wood veneer (Black Ash or American Walnut)
- Material: Two layers of MDF (total thickness: 20 mm / 0.8 in)

For those looking for a sound experience that marries modern acoustic engineering with traditional design elements, the ZGB-401 is an outstanding choice. This perfect blend enables it to deliver extraordinary sound quality in a package that beautifies the space it occupies.

ZGB-401


High End Munich 2024 is set to feature the SOUNDSCLEVER initiative, a highlight for audiophiles looking for high-quality audio systems without the high price tag. SOUNDSCLEVER offers a unique standard and guide for visitors, showcasing complete audio systems that deliver exceptional sound performance, all for less than EUR 5,000.

**Entry-Level Systems with Premium Performance**

SOUNDSCLEVER presents an opportunity for visitors to experience technical and musical excellence in audio systems assembled with budget-conscious audiophiles in mind. Throughout the HIGH END exhibition, various industry professionals will present their contributions to this initiative, adhering to the price limit but without restrictions on the configuration. This flexibility allows for a wide range of system types, from strictly digital setups to high-end analog configurations, or combinations of both within one hi-fi system.

**Navigating the Exhibition**

Attendees can easily find SOUNDSCLEVER systems across the exhibition, guided by direction signs adorned with the SOUNDSCLEVER logo. Here are some exhibitors showcasing these systems:

-   **Lindemann** (Atrium 4.2, F231b): Features the Woodnote Combo network player, Lindemann Move mini speakers, and high-quality cables, totaling EUR 4358.
-   **audioNEXT** (Atrium 4.1, E123): Includes the eversolo DMP-A6 Streaming-DAC, eversolo AMP-F2 amplifier, and EPOS ES-7N speakers, with a system total of EUR 4921.
-   **Sonoro audio** (Halle 2 Stand J04): Showcases the sonoro PLATINUM turntable, Sonoro MEASTRO quantum receiver, and sonoro GRAND ORCHESTRA speakers, with a total of EUR 4996.
-   **Custom Audio** (Halle 2 G17): Features the Xtonebox 121ST turntable, Xtonebox Silver-6011 amplifier, and Xtonebox S-10C speakers, totaling EUR 4470.
-   **ELAC** (Atrium 4.1 F103): Presents the ELAC Miracord 50 turntable, ELAC DEBUT CONNEX DCB41 active speakers, and ELAC DEBUT S10 subwoofer, totaling EUR 1417.

**Why SOUNDSCLEVER?**

The SOUNDSCLEVER initiative not only makes high-end audio more accessible but also educates and encourages visitors to explore how exceptional sound can be achieved within a reasonable budget. It's an ideal platform for newcomers to high fidelity and seasoned audiophiles alike to discover systems that provide a gateway to superior audio experiences without the hefty investment typically associated with high-end setups.

[More details ...](https://www.highendsociety.de/files/highend/soundsclever/HE23%20SoundsClever_web.pdf)

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SOUNDSCLEVER at High End Munich 2024: Affordable High-Fidelity Systems

Lindemann is a German audio brand that produces high-quality audio equipment such as amplifiers, digital-to-analog converters, and speakers.

Lindemann

audioNEXT

Epos is a brand that specializes in the design and manufacture of high-quality audio equipment, including speakers and headphones.

Epos

Sonoro is a German audio brand known for their high-quality audio products such as radios and music systems.

Sonoro

Custom Audio

ELAC is a brand known for its high-quality HiFi audio products.

ELAC

Visit High End Munich 2024 to see SOUNDSCLEVER's showcase of exceptional yet affordable audio systems by top brands like Lindemann and Sonoro, all under EUR 5,000

#### Why Acoustic Terminology Matters

Understanding the language of acoustics is not just for scientists or sound engineers; it's essential for anyone passionate about achieving the best sound experience, whether you're an audiophile or a professional. Knowing terms like "Reverberation" or "Absorption" can help you diagnose problems in your listening room or even enhance your enjoyment of music or movies.

#### The Four Pillars

At the heart of acoustic understanding are four key terms: Reverberation, Absorption, Reflection, and Diffusion. Think of these as the four pillars that uphold the 'temple' of sound quality. Understanding these terms can significantly elevate your listening experience.

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### Unpacking Reverberation

#### What is Reverberation?

Reverberation is the continuation of sound in a particular space even after the original sound source has stopped. Imagine clapping your hands in an empty room; the sound lingers for a few moments, bouncing off the walls, ceiling, and floor. That lingering is reverberation. Too much of it can muddy sound quality, while too little can make a room feel "dead."

#### Reverberation Time (RT60)

RT60 is a metric that measures how long it takes for the sound to decay by 60 decibels in a room. In simple terms, it gauges how 'echoey' a room is. Measuring RT60 helps in tuning a room for optimal sound quality. For example, a home theater might aim for a shorter RT60 to keep dialogues crisp, while a concert hall might aim for a longer RT60 to enrich musical notes.

#### The Role of Reverberation in Different Environments

Reverberation behaves differently depending on where you are. In a recording studio, excessive reverberation is usually undesirable as it can muddle the clarity of recordings. Conversely, in a concert hall, a certain level of reverberation can add richness and warmth to live performances. Even in your living room, getting the reverberation right can make your hi-fi system shine.

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### The Absorption Factor

#### What is Sound Absorption?

Sound absorption refers to the process where materials, like acoustic foam or carpeting, "soak up" sound waves, reducing echo and background noise. Imagine sound absorption like a sponge soaking up water, but in this case, the sponge is soaking up sound energy.

#### Noise Reduction Coefficient (NRC)

The Noise Reduction Coefficient (NRC) is a number between 0 and 1 that indicates how well a material absorbs sound. A higher NRC means better absorption. For example, acoustic ceiling tiles with an NRC of 0.7 would absorb 70% of the sound hitting them, reflecting the remaining 30% back into the room.

#### Practical Applications of Absorption

In a home theater, strategic placement of absorbing materials can help reduce unwanted noise and echoes, making dialogues and musical scores clearer. In recording studios, absorption is essential for capturing the 'true' sound of an instrument or voice without interference from the room itself. Even in industrial settings, absorption can be crucial for employee comfort and safety, mitigating the impact of machine noise.

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### Understanding Reflection

#### The Basics of Sound Reflection

Sound reflection is the phenomenon where sound waves bounce off surfaces like walls, floors, and ceilings. Imagine throwing a ball at a wall; it comes back to you, right? Sound behaves similarly. When sound waves encounter a hard surface, they reflect back into the room. This can either be a positive or negative factor, depending on what you're aiming for acoustically.

#### First Reflection Points

First reflection points are the initial surfaces that sound waves hit after leaving a speaker. They're critical because these first reflections will reach the listener almost immediately after the direct sound, and can either clarify or muddy the sonic picture. In most cases, these are spots on your side walls, ceiling, or floor. Knowing where these points are can help you decide where to place absorbing or diffusive materials.

#### Reflective Surfaces and Sound Quality

Reflective surfaces aren't all bad; sometimes they're exactly what a room needs. For example, in a home theater, you might want some reflection off the side walls to make the audio sound more spacious. However, in a recording studio, excessive reflection could distort the true sound of an instrument or voice. The key is to find a balance between reflective and absorbent surfaces.

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### The Complexity of Diffusion

#### What is Sound Diffusion?

Diffusion is the scattering of sound waves in multiple directions. Unlike absorption or reflection, which deal with sound in a more linear way, diffusion disperses sound, reducing the sense of localization. Think of it like a garden sprinkler for sound; it scatters water (sound) uniformly in different directions.

#### Types of Diffusers

There are various types of diffusers, but two common ones are Quadratic Residue Diffusers (QRD) and Primitive Root Diffusers (PRD). QRDs use a sequence of well depths to scatter sound, while PRDs utilize a different mathematical formula for a more randomized scattering. Both have their strengths and weaknesses, but the goal is the same: to spread sound energy across a room evenly.

#### The Role of Diffusion in Room Acoustics

Diffusion can enhance a space by making it sound larger and more open. It helps break up sound energy and redistributes it throughout the room. This is beneficial in places like home theaters where you want a balanced, immersive sound field, or in music studios where you want to capture a more natural ambiance.

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### Putting it All Together

#### The Interplay Between the Four Terms

Understanding Reverberation, Absorption, Reflection, and Diffusion in isolation is good, but appreciating how they interact is even better. For instance, too much absorption can make a room sound lifeless, but adding diffusion can breathe life back into it. Likewise, too much reflection could cause problems, but the right amount of reverberation could fix it.

#### Case Studies

Real-world examples can illustrate how a blend of these four elements can create an acoustically optimized space. Whether it's a Grammy-winning recording studio or a state-of-the-art home theater, the principles remain the same: balance and harmony between these four pillars.

#### Final Thoughts and Further Resources

Mastering these terms is essential for anyone interested in acoustics, whether you're a professional or just passionate about sound. For those looking to deepen their knowledge, various books, online courses, and consultation services are available to guide you further.

Photo of a modern HiFi listening room.png

What is Reverberation, Absorption, Reflection, and Diffusion

A proper understanding of acoustical terminology is essential for effective room treatment. Learn how they impact room treatment and sound quality.


In the realm of high-fidelity audio, there's an invisible dance happening right in our living spaces – a performance by sound waves influenced by the very rooms we sit in. This is the world of room modes and standing waves, where physics meets the ear, often with less-than-desirable outcomes for audiophiles.

## The Essence of Room Modes

Imagine your room is a container, and sound is water. When you pour water into it, some waves crash against the walls and interfere with the incoming waves, creating ripples of varying sizes and strengths. Replace water with sound, and you have an analogy for room modes.

Technically, room modes are specific frequencies that resonate more than others due to the dimensions of a room. It's like when a singer hits a particular note and a glass shatters – the glass resonates with that note. Your room, too, has 'favorite' notes, which are the room modes. These favorites depend on the length, width, and height of the room, creating a unique acoustic fingerprint.

## When Waves Stand Still: Standing Waves

Standing waves, on the other hand, are the stubborn notes that seem to hover in the air. In a perfectly reflective room, a sound wave can bounce back and forth, eventually superimposing upon its own echo. When two such waves traveling in opposite directions meet, they form a standing wave – a spot where certain notes linger, refusing to fade away. These spots can either amplify the sound (making it louder) or cancel it out (creating dead zones).

## Technical Interlude: The Math Behind the Music

If you're curious about the technical nitty-gritty, room modes can be predicted using basic formulas. For instance, the lowest frequency that will create a standing wave between two parallel walls (axial mode) can be calculated by dividing the speed of sound (approximately 343 meters per second) by twice the distance between the walls. But fear not, you don't need to solve equations to understand the practical implications.

## The Real-World Effects on Your Listening Experience

The result of these acoustical phenomena is an uneven bass response. Some bass notes might boom, overwhelming the melody, while others might barely whisper. In the context of listening to music, this means the bass guitarist in your favorite band might sound like they’re playing a solo when they’re not, or they might seem to disappear altogether.

## Taming the Acoustic Beasts

How do we tame these unruly resonances? Acoustic treatment is the key. This includes adding absorptive materials, like acoustic panels or even bookshelves stuffed with books, to disrupt the path of the sound waves and reduce their ability to bounce back and forth. Strategically placing your speakers and listening position can also help you avoid the worst effects of standing waves.

Another ally in the battle against room modes is equalization (EQ), where you adjust the levels of specific frequencies. However, this is more of a band-aid than a cure, as it doesn't remove the cause of the problem.

## Accessibility for All Ears

Understanding and addressing room modes is essential because good sound should be accessible to everyone, everywhere. Whether you're in a cozy attic or a spacious living room, knowledge about how sound interacts with space can enhance your listening experience.

In the end, it’s all about balance. We can't completely eliminate room modes or standing waves, but we can learn to live with them harmoniously. By knowing your room's acoustic personality, you can set up your HiFi system to sing in tune with your space, ensuring that every note reaches your ears as the artist intended.

So, the next time you press play on your favorite album, remember the silent symphony playing in the architecture around you. With a little understanding and effort, you can conduct that symphony to support the soundtrack of your life, note by perfect note.

a modern living room focusing on a single speaker. Visible around the speaker are stylized, semi-transparent flutter echoes or waveforms that

a modern living room focusing on a single speaker.png

Understanding Room Modes and Standing Waves in HiFi

Understand the impact of room modes and standing waves on HiFi audio

ZGB-401

by Unitra

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SOUNDSCLEVER at High End Munich 2024: Affordable High-Fidelity Systems

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Understanding Room Modes and Standing Waves in HiFi