Feliks Audio is a company that specializes in high-end audio equipment, particularly tube amplifiers and headphone amplifiers.

 Feliks Audio

## The Fundamentals of Sound Absorption

**The Phenomenon of Sound Absorption:** 
Sound absorption is a crucial aspect of acoustic engineering, which deals with the control of sound and reverberation in a given space. When sound waves encounter a material, part of the acoustic energy is absorbed by the material, transforming into heat, while the rest may be reflected or transmitted through. The level of absorption depends on the material’s properties and the frequency of the sound wave. By absorbing unwanted sound, these materials help in creating acoustically pleasant environments, crucial for settings like recording studios, theaters, and homes with high-fidelity audio setups.

**Acoustic Energy Transformation: From Sound to Heat:** 
The principle behind sound absorption lies in the conversion of acoustic energy into heat. When a sound wave hits a material, the material’s fibers or structure vibrates, causing internal friction which generates heat. This process dissipates the acoustic energy, thereby reducing the sound wave’s amplitude and mitigating the amount of sound reflected back into the room.

**Acoustic Impedance:** 
The Gateway to Effective Sound Absorption: Acoustic impedance is a measure of how much a material resists or permits the flow of acoustic energy. It is crucial for understanding a material’s sound absorbing capacity. Materials with an impedance matching that of air tend to absorb sound more effectively as they allow for better transmission of sound waves into the material where it can be dissipated as heat.

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## An In-depth Look at Sound-Absorbing Materials

**Material Properties Influencing Sound Absorption**
The sound absorption efficiency of a material is significantly influenced by its density, thickness, and surface texture. Dense materials with open structures, like foam or fiberglass, are excellent at trapping sound waves. Moreover, thicker materials tend to absorb lower frequency sounds better due to their ability to vibrate at lower frequencies.

**The Dynamic Trio: Fiberglass, Foam, and Rockwool** 
Among the most commonly used sound-absorbing materials are fiberglass, foam, and rockwool. Fiberglass is renowned for its excellent sound absorption capabilities across a broad frequency spectrum. Foam, particularly open-cell foam, is effective at absorbing higher frequency sounds. Rockwool, with its dense and fibrous structure, is adept at absorbing a wide range of frequencies, making it a popular choice for various acoustic treatment applications.

**Comparative Analysis of Sound Absorption Efficiency** 
Each of these materials has its own set of advantages and disadvantages. For instance, while fiberglass and rockwool are effective across a broad spectrum of frequencies, foam tends to be less effective at lower frequencies. The choice between these materials depends on the specific acoustic needs of a space, and often, a combination of materials is employed to achieve desired acoustic properties.

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## Beyond the Basics: Unveiling Additional Sound-Absorbing Materials

**The Role of Bass Traps in Low-Frequency Sound Absorption**
Low-frequency sounds are often the most challenging to control. Bass traps are designed to tackle these lower frequency sounds, providing control over boomy and muddy acoustics often encountered in untreated rooms.

**Perforated Wood Panels: Blending Aesthetics with Acoustics**
Perforated wood panels not only offer sound absorption qualities but also add an aesthetic appeal to a room. They are particularly effective in treating mid to high-frequency sounds, making them a suitable choice for spaces that require a visually pleasing acoustic treatment solution.

**Unconventional Materials: Exploring the Unknown**
The field of acoustic engineering constantly evolves with the discovery and development of new materials. Unconventional materials like recycled rubber, cork, and even certain types of plastics are being explored for their sound absorbing properties. These materials open up new avenues for effective sound control while often providing eco-friendly alternatives to traditional acoustic materials.

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## Health and Safety Concerns in Acoustic Material Selection

**The Specter of Volatile Organic Compounds (VOCs)**
Volatile Organic Compounds (VOCs) are carbon-based chemicals that evaporate at room temperature, and some of them are harmful when inhaled. Many traditional sound-absorbing materials, like certain adhesives or foams, may emit VOCs, which can lead to poor indoor air quality. It's essential to select materials that have low VOC emissions to ensure a healthy indoor environment.

**Fire Safety Ratings and Acoustic Materials**
Fire safety is a paramount consideration when selecting acoustic materials. Materials should have appropriate fire safety ratings to ensure they won't easily ignite or contribute to the spread of fire. It's prudent to check the fire safety ratings and certifications of acoustic materials, and opt for those that are tested and certified as fire-resistant or fire-retardant.

**Navigating Health Regulations in Acoustic Engineering**
Complying with health and safety regulations is crucial in acoustic material selection. Ensuring that materials meet the standards set by local and international health agencies will not only promote safety but also demonstrate a commitment to adhering to best practices in acoustic engineering.

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## Effective Room Treatment Strategies

**The Art and Science of Material Placement** 
Effective room treatment goes beyond merely selecting the right materials; it extends to the strategic placement of these materials within a space. By understanding the flow of sound within a room and identifying areas where sound reflection is problematic, one can place sound-absorbing materials strategically to reduce echo and reverberation.

**Case Studies: Before and After Room Treatment** 
Examining real-world examples of room treatment can provide invaluable insights into the impact of sound-absorbing materials on a space's acoustic quality. Through a series of case studies, this section will explore various room treatment strategies and their outcomes, providing a practical understanding of how sound absorption can transform a sonic environment.

**Measuring the Impact: Tools and Techniques for Assessing Acoustic Performance** 
Utilizing tools like sound level meters and acoustic analysis software, individuals can measure the impact of room treatment on a space's acoustic performance. These tools provide data that can guide further adjustments, ensuring that the room treatment strategy achieves the desired acoustic results.

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## Future Trends in Sound Absorption Technology

**Emerging Materials on the Horizon** 
The acoustic engineering field is on the brink of exploring new materials with enhanced sound absorption properties. Innovations in material science are paving the way for the introduction of materials with superior acoustic performance, such as metamaterials which exhibit properties not found in naturally occurring materials.

**The Potential of Nanotechnology in Acoustic Engineering**
Nanotechnology holds promise in revolutionizing acoustic material design. By manipulating materials at a nanoscale, engineers can create structures with enhanced sound absorption properties, potentially leading to new categories of acoustic materials with exceptional performance.

**Sustainable Practices in Sound Absorption Material Production** 
With a growing emphasis on sustainability, the trend towards the utilization of recycled and eco-friendly materials in acoustic engineering is gaining momentum. Sustainable practices in material production not only contribute to environmental conservation but also resonate with a growing segment of eco-conscious consumers, making it a win-win scenario for both the industry and the planet.

a porous absorption material.png

The Science of Sound Absorption

Explore the profound science of sound absorption and its impact on room acoustics. Delve into the characteristics of various sound-absorbing materials like fiberglass, foam, and rockwool, and understand their application in creating sonically pleasant spaces. Uncover essential health and safety considerations alongside emerging trends in acoustic engineering for a well-rounded grasp on enhancing audio experiences.


In a landmark release that's stirring both nostalgia and excitement, The Beatles have unveiled the expanded 2023 editions of their classic compilations: "The Beatles 1962-1966 (Red Album)" and "The Beatles 1967-1970 (Blue Album)". These editions mark a significant leap in audio technology, bringing a fresh perspective to these timeless tracks.

Central to the 2023 release is the extensive use of modern remixing and remastering techniques. For the 'Red Album', listeners are treated to 30 tracks out of 38 that have been newly remixed, offering a much more detailed and wide-spectrum stereo sound. The enhancements are particularly notable in the clarity of individual voices and the distinctness of instruments, bringing a newfound vibrancy to these beloved songs.

The release also includes the long-awaited completion of the final Beatles song, "Now And Then". This track, originating from a John Lennon demo from the late 1970s, was completed using advanced audio separation technology. The inclusion of this song has been a highlight for fans, showcasing the potential of modern technology to bring unfinished works to life.

Both the 'Red' and 'Blue' albums have been expanded to include additional tracks, further enriching the Beatles' musical narrative. The 'Blue Album' sees six new remixes and a total of nine added songs. These updates offer listeners a more comprehensive view of The Beatles’ musical evolution.

The response to these new editions has been diverse. While many fans and critics have lauded the technological enhancements and the inclusion of "Now And Then", some purists have expressed concerns over the alterations from the original recordings. The varied reactions underscore the deep connection many have with The Beatles’ music and the complexities involved in balancing preservation with innovation.

Commercially, the albums have mirrored their original success, with the 'Blue Album' reaching number 2 and the 'Red Album' number 3 in the UK. The new song "Now And Then" has notably achieved significant popularity, a testament to the enduring legacy of The Beatles in contemporary music culture.

This release is not just a trip down memory lane; it's a bold step into the future of music preservation and appreciation, blending the timeless appeal of The Beatles with the possibilities offered by modern audio technology.

The-Beatles-Red-Blue-2023.webp

The Beatles' Iconic "Red" and "Blue" Albums Reimagined for 2023

Rediscover The Beatles with the 2023 remixes of the iconic 'Red' and 'Blue' Albums, including the much-anticipated track 'Now And Then'.

This isn't an exhaustive review with numerous tests. Instead, it's an initial attempt to select a phono preamp within a budget from well-known models available on popular platforms like Amazon. While there may be better models or used options within the same price range, this post focuses on first impressions.

Our setup included McIntosh speakers, a custom-made turntable (limited edition but entry-level) with a brand new Ortofon S10 cartridge, a Denon receiver (to stay within the same price range), and a McIntosh headphone tube amp (MHA200) with McIntosh MHP1000 headphones for the final check-up.

The idea for this article stemmed from the need to connect our turntable to a Denon receiver, necessitating a phono preamp. We tested each preamp using tracks from Frank Sinatra, Sade, and The Weeknd to cover a range of vocal and instrumental styles, ensuring a comprehensive evaluation.

### Pro-Ject Tube Box S2 (Tube)

![IMG_6540.jpeg](https://storage.googleapis.com/hifi-cdn/IMG_6540_e44acf8231/IMG_6540_e44acf8231.jpeg)

**Description and Sound Characteristics** 

The [Pro-Ject Tube Box S2 (Tube)](https://hifi.fan/pro-ject-tube-box-s2) stands out for its warm, engaging sound. It delivers a rich and textured sound signature, with an excellent soundstage that creates an immersive listening experience. The vocals are centered and clear, giving a sense of presence and involvement. The instrument separation is outstanding, making each component of the music distinctly audible. This preamp excels in providing a spacious auditory experience, extending the sound well beyond the speakers. Additionally, its compact and aesthetically pleasing design makes it a perfect companion to sit next to your turntable.

**Impressions** 

Listening to Frank Sinatra through the Tube Box S2 was a revelation. His vocals felt as if they were right in front of you, with the ensemble clearly positioned behind him. The bass guitar in general listening sessions was clear and vibrant, with a sense of movement between the speakers and noticeable reverberation and echo. The overall engagement was high, making you want to keep listening.

**Pros and Cons**

-   **Pros**: Warm, engaging sound with excellent separation and soundstage. Compact and attractive design.
-   **Cons**: None noted in this initial impression.

### Cambridge Audio Alva Duo

![IMG_6545.jpeg](https://storage.googleapis.com/hifi-cdn/IMG_6545_5e75b92d0f/IMG_6545_5e75b92d0f.jpeg)

**Description and Sound Characteristics**  

The [Cambridge Audio Alva Duo](https://hifi.fan/cambridge-audio-alva-duo) offers clarity and precision, though it may lack some of the warmth and detail found in the Tube Box S2. It provides a clear sound that feels somewhat confined between the speakers. For its price, it delivers good performance, with vocals that are clear but might miss some mid-range or high details. The separation is adequate but not exceptional, sometimes sounding too pure and lacking colorization. It is relatively large and may require a separate shelf in a vertical rack. On the plus side, it includes an integrated headphone amplifier and supports both MC and MM cartridges, adding versatility.

**Impressions** 

Playing Sade on the Alva Duo revealed a slightly dull sound with no pronounced bass. While the sound was clear and detailed, it lacked the extension and separation that the Tube Box S2 offered. In general listening, the detail retrieval was good, especially noticeable in the cymbals, but it lacked some richness and presence in more complex musical passages.

**Pros and Cons**

-   **Pros**: Clear and detailed sound, good value for the price. Integrated headphone amplifier and support for both MC and MM cartridges.
-   **Cons**: May lack warmth and engagement, not as good separation as the Tube. Larger size may require additional space.

### Pro-Ject Phono Box E

![IMG_6550.jpeg](https://storage.googleapis.com/hifi-cdn/IMG_6550_218e952b69/IMG_6550_218e952b69.jpeg)

**Description and Sound Characteristics** 

The [Pro-Ject Phono Box E](https://hifi.fan/pro-ject-phono-box-e) is a budget-friendly option that still offers good detail, particularly in the midrange. It provides a satisfactory performance considering its price, with a soundstage that is sufficient but not as expansive as the Tube Box S2. The overall engagement is lower, lacking the richness and presence of the higher-end models. Vocals are clear, but the sound might feel a bit constrained.

**Visual and Functional Aspects** 

Visually, the Phono Box E is compact and easy to hide, making it a practical choice for those with limited space. In terms of functionality, it lacks a standby button, which might be a drawback for some users. However, it remains a solid choice for those on a budget.

**Pros and Cons**

-   **Pros**: Good detail for the price, compact size.
-   **Cons**: Lacks the richness and separation of higher-end models.

### Listening Experience with McIntosh Headphones and McIntosh Tube Amp MHA200

![IMG_6553.jpeg](https://storage.googleapis.com/hifi-cdn/IMG_6553_eb166c1a8b/IMG_6553_eb166c1a8b.jpeg)

Using McIntosh MHP1000 headphones and the McIntosh headphone tube amp MHA200, the Pro-Ject Tube Box S2 offered a warm, engaging sound that was not tiring and felt natural and pleasant. With the Tube phono preamp, you just want to listen and listen; it is highly engaging. The Cambridge Audio Alva Duo was clear and detailed but sometimes felt too digital, lacking the natural warmth of the Tube. The Pro-Ject Phono Box E provided good performance for its price but lacked the richness and separation of the other two.

Listening to the Cambridge Audio Alva Duo with the McIntosh setup revealed a clear but somewhat digital sound, lacking engagement. The dynamics were good, but it could feel sharp at times. In contrast, the Tube on the McIntosh setup was the most musical and pleasant among the tested units, offering a soft, natural sound that did not cause fatigue. The Cambridge might perform better with mid-range speakers due to its clear, precise sound, while the Tube excels with high-quality components and headphones, providing a more musical experience.

### Conclusion

In our final comparison using the McIntosh headphone tube amp and headphones, we were impressed with the sound of the Tube phono preamp.

-   **[Pro-Ject Tube Box S2 (Tube)](https://hifi.fan/pro-ject-tube-box-s2)**: Best for those seeking a warm, engaging sound with excellent separation and soundstage. Its compact and attractive design is an added bonus.
-   **[Cambridge Audio Alva Duo](https://hifi.fan/cambridge-audio-alva-duo)**: A solid choice for clear, detailed sound but might lack warmth and engagement. Its integrated headphone amplifier and support for both MC and MM cartridges add versatility.
-   **[Pro-Ject Phono Box E](https://hifi.fan/pro-ject-phono-box-e)**: Best budget option, offering good performance for the price but missing some richness and separation compared to the higher-end models.

If your equipment isn't top-tier, the Pro-Ject Phono Box E is a good pick. If you’re unsure about choosing between MM or MC cartridges, the Cambridge Audio Alva Duo is a versatile option. However, for the best sound, aesthetics, size, and performance, we highly recommend the Tube amp. It offers an upgrade path as you improve other components of your system.

Hope this was helpful for everyone!

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First Impressions of Phono Preamps: Pro-Ject Tube Box S2, Cambridge Audio Alva Duo, and Pro-Ject Phono Box E

Pro-Ject is a brand that specializes in manufacturing high-quality turntables and audio equipment.

Pro-Ject

Cambridge Audio is a brand that specializes in the design and manufacture of high-quality audio equipment.

Cambridge Audio

McIntosh Laboratory, Inc., often referred to simply as McIntosh, is an esteemed American brand renowned for its high-quality audio equipment. Founded in 1949 in Binghamton, New York, McIntosh has established itself as a pioneer in the high-fidelity audio industry. The brand is synonymous with enduring build quality, aesthetic elegance, and unparalleled sound performance, making it a choice of audiophiles and music enthusiasts worldwide.

Known for its distinctive design, McIntosh products feature signature black glass front panels, aluminum end caps, and the iconic "McIntosh Blue" watt meters, which have become a symbol of audio excellence. Their product range encompasses a wide array of audio equipment, including amplifiers, preamplifiers, speakers, turntables, and other audio accessories, each crafted with meticulous attention to detail and acoustic perfection.

McIntosh's dedication to producing high-quality sound reproduction is evident in their use of advanced technologies and precision engineering. Their products are often the result of extensive research and development, ensuring that they not only meet but exceed industry standards.

In addition to sound quality, McIntosh is committed to the longevity and durability of its products. Many McIntosh units from decades past are still in use today, a testament to their build quality and the company's commitment to sustainability through longevity.

Whether for home audio systems, professional studios, or luxury car audio, McIntosh provides an audio experience that is both immersive and emotionally engaging, offering a level of performance that is as close to the original recording as possible. Their legacy and ongoing innovation continue to set the standard in high-end audio, making McIntosh a prestigious and revered name in the world of hi-fi audio systems.

McIntosh

Our initial impressions of the Pro-Ject Tube Box S2, Cambridge Audio Alva Duo, and Pro-Ject Phono Box E phono preamps

The Pro-Ject Tube Box S2 is a favorite among audiophiles who appreciate the warm, rich sound that only a tube phono preamp can deliver. This compact and aesthetically pleasing preamp is designed to sit perfectly next to your turntable, bringing an analog warmth and depth to your vinyl records.

The Tube Box S2 features dual mono configuration and high-quality ECC83 tubes, ensuring an immersive listening experience with excellent soundstage and instrument separation. The vocals are textured and centered, creating a sense of presence and involvement that keeps you engaged with your music.

Key features include:

Dual Mono Configuration: Ensures superior channel separation and audio clarity.

High-Quality ECC83 Tubes: Delivers warm, rich sound with exceptional detail and dynamics.
Adjustable Gain: Flexible settings to match different cartridges for optimal performance.
Compact Design: Fits neatly next to your turntable, adding a stylish touch to your audio setup.

The Pro-Ject Tube Box S2 is ideal for those who seek a warm, engaging sound with excellent separation and soundstage. Its compact size and attractive design make it a perfect addition to any vinyl enthusiast's setup. Audiophiles will appreciate the enhanced musicality and presence that this tube phono preamp brings to their record collection.

Tube Box S2

The Pro-Ject Phono Box E is an excellent entry-level phono preamp that offers great value without compromising on sound quality. Designed for those who are new to the world of vinyl or on a budget, this compact preamp provides the essential features needed to enjoy your record collection with clarity and detail.

Despite its affordable price, the Phono Box E delivers good midrange detail and a satisfactory soundstage. It’s designed to work with Moving Magnet (MM) cartridges, making it a simple yet effective solution for connecting your turntable to a line-level input on your amplifier or receiver.

Key features include:

Budget-Friendly: High-quality sound at an affordable price, perfect for those new to vinyl.

MM Cartridge Compatibility: Optimized for Moving Magnet cartridges, providing clear and accurate playback.
Compact Design: Easily fits into any setup and can be hidden away due to its small size.
Simple Setup: Easy to install and use, making it ideal for beginners.

The Pro-Ject Phono Box E is a solid choice for vinyl enthusiasts looking for an affordable phono preamp that doesn’t skimp on performance. Its compact design and ease of use make it a practical addition to any audio setup, offering a taste of high-fidelity sound without breaking the bank.

Phono Box E

MHA200

MHP1000

The Cambridge Audio Alva Duo Phono Preamp is a must-have for audiophiles seeking precision and clarity in their vinyl listening experience. Compatible with both Moving Magnet (MM) and Moving Coil (MC) cartridges, the Alva Duo ensures that your records sound exceptional, no matter your cartridge choice.

This versatile preamp delivers a clear and detailed sound that brings out the subtle nuances of your favorite tracks. The integrated headphone amplifier allows for an intimate listening experience, perfect for those who enjoy the depth and detail that headphones can provide. Its modern design seamlessly integrates into your existing setup, although it may require dedicated shelf space due to its robust build.

Key features include:

MM and MC Compatibility: Flexibility to use either cartridge type for a versatile listening experience.
Integrated Headphone Amplifier: Exceptional clarity and detail through your headphones for personal enjoyment.

Precision Engineering: High-quality components deliver clear, precise sound, revealing the finest details in your music.

User-Friendly Design: Easy to set up and use, ideal for both beginners and experienced audiophiles.

Feliks Audio

Feliks Audio Showcases Groundbreaking Amplifiers at Munich Audio Show

Interesting articles

The Science of Sound Absorption

The Beatles' Iconic "Red" and "Blue" Albums Reimagined for 2023

First Impressions of Phono Preamps: Pro-Ject Tube Box S2, Cambridge Audio Alva Duo, and Pro-Ject Phono Box E