Stenheim Alumine Two.Five: A Detailed Review 

Switzerland has long been a bastion of precision engineering, and in the realm of high-end audio, Stenheim stands out as a manufacturer embodying this tradition. Renowned for their meticulous approach and distinctive use of aluminum in loudspeaker construction, Stenheim has garnered a reputation for producing sonically pure and aesthetically refined audio equipment. The Alumine Two.Five represents the latest exciting addition to their esteemed Alumine range, marking the introduction of their first floorstanding model in this series. Strategically positioned between the compact Alumine Two bookshelf speaker and the more substantial Alumine Three floorstander, the Two.Five aims to bridge the gap, offering an enhanced listening experience with greater bass extension while retaining the core design principles that have made the Alumine Two an iconic product.

The original Alumine Two bookshelf speaker has achieved considerable acclaim, having redefined expectations for what could be achieved from a loudspeaker of its size. Its success stemmed from a combination of key elements: meticulously crafted aluminum cabinets, highly efficient drivers, and sophisticated crossover networks designed to be as transparent as possible. A significant factor in the Alumine Two's remarkable musicality was its two-way design, which simplified the crossover, requiring it to manage only two drivers – the tweeter and the bass unit. This philosophy of simplicity, often considered the holy grail in audio design, is notoriously difficult to execute effectively. Now, the Alumine Two.Five takes these same fundamental design concepts and applies them to a floorstanding cabinet, allowing for a larger internal volume and consequently, a greater extension in the lower frequencies. Despite the move to a floorstanding format, the Two.Five remains a two-way design, deliberately avoiding the potential complexities and compromises that can arise from more intricate crossover designs needed for multiple different drivers. This ensures that the purity and simplicity that underpinned the success of the Alumine Two are maintained, while the inclusion of double bass drivers allows for a more room-filling sound in larger spaces and a deeper reach into the bass регион. Adding to its appeal, the Alumine Two.Five is designed to be easily driven, making it suitable for a wide range of high-quality amplifiers, even those with modest power outputs, such as tube amplifiers, promising an enthralling musical experience characterized by Stenheim's signature clarity, detail, and liveliness.

The initial reception of the Stenheim Alumine Two.Five from the audio press has been overwhelmingly positive. HiFi+, a highly influential UK magazine, featured the speaker prominently, bestowing upon it the prestigious "Hall of Fame" status and declaring it, "the single best pair of speakers I have ever auditioned in my listening room, regardless of price or system pairing". Similarly, Home Theater HiFi was equally enthusiastic, describing the Two.Five as "gorgeously honest, divinely minimalist, purpose-forward design that is perfectly proportioned for most rooms" and praising its "incredible performance from a modest-sized floor-standing speaker". These strong endorsements from respected publications suggest that the Alumine Two.Five is a loudspeaker that demands serious attention from audiophiles seeking exceptional sonic performance.

Engineering Excellence: Design and Build

The cornerstone of the Stenheim Alumine Two.Five's design is its meticulously constructed cabinet, fashioned from thick sheets of aluminum. This choice of material is no accident; aluminum offers significant advantages in terms of stiffness and the ability to minimize unwanted resonances. Unlike traditional wooden cabinets, the aluminum enclosure of the Two.Five exhibits remarkably low vibration, providing an exceptionally stable and inert platform for the drivers. This rigidity directly translates to a cleaner and more detailed sound, as there is minimal cabinet interference to mask the subtle nuances within the music. The absence of added coloration from the cabinet allows the true sonic character of the recording to emerge, unadulterated by the speaker's physical structure.

Beyond its sonic benefits, the aluminum construction also contributes to the Alumine Two.Five's distinct aesthetic. The design is clean, minimalist, and evokes a Bauhaus-inspired sensibility, emphasizing function and understated elegance. Recognizing that visual appeal is also important, Stenheim offers the Alumine Two.Five in a range of sophisticated colors, including Metallic Light Grey, Dark Grey, Black, Ivory, and Mocca, ensuring that the speakers can seamlessly integrate into a variety of listening spaces and interior décors.

The driver complement of the Alumine Two.Five consists of two 16.5cm (6.5”) woofers paired with paper cones and a single 2.6cm (1”) soft dome tweeter featuring a silk diaphragm. These drivers are not off-the-shelf components but are manufactured to Stenheim's exacting specifications. The use of paper for the woofer cones often suggests a natural and warm presentation in the midrange and lower frequencies, while silk dome tweeters are typically chosen for their smooth and detailed reproduction of high frequencies. Furthermore, each driver is specially coated to achieve the desired performance characteristics, indicating a meticulous approach to fine-tuning the speaker's sonic output.

Sticking to the design philosophy of its predecessor, the Alumine Two.Five employs a two-way configuration. This approach, while seemingly simple, can yield significant benefits in terms of sonic coherence and purity. By using only two drivers, the complexity of the crossover network is reduced, minimizing the potential for phase anomalies and ensuring a more seamless integration of the different frequency ranges. The Alumine Two.Five features a front-mounted bass reflex port. This design choice allows for greater extension in the bass frequencies compared to a sealed cabinet while offering more flexibility in terms of room placement than rear-ported designs. A front port makes the speakers less sensitive to being positioned close to rear walls, which can often lead to an overemphasis or unevenness in bass response with rear-ported loudspeakers.

The crossover network within the Alumine Two.Five is engineered with precision and utilizes high-grade, audiophile-grade components. This commitment to quality ensures minimal signal degradation and contributes to the speaker's overall sonic transparency and ability to resolve fine details. Stenheim's design philosophy aims for the crossover to be as unobtrusive as possible. This means that the crossover is carefully engineered to seamlessly blend the output of the tweeter and woofers, allowing each driver to operate optimally within its designated frequency range without introducing any noticeable sonic artifacts or distortions.

Technical Specifications at a Glance

The Listening Experience: Unveiling the Sonic Landscape

The Stenheim Alumine Two.Five presents a captivating listening experience characterized by remarkable clarity, detail, and a cohesive musical presentation. The high-frequency performance is noteworthy for its smoothness and extension. The silk dome tweeter renders the upper registers with a delicate touch, offering sparkling highs that possess airiness and detail without ever sounding harsh or strident. There is a distinct absence of any annoying sibilance, contributing to a fatigue-free listening session even over extended periods. Strings, for instance, are reproduced with a palpable texture, showcasing the tweeter's ability to resolve fine nuances in the higher frequencies.

Moving to the midrange, the Alumine Two.Five exhibits exceptional transparency and neutrality. Vocals are presented with clarity and articulation, conveying the unique character of each singer's voice. Whether it's the iconic voice of Beyoncé, where the speakers reveal striking layers in her recordings, or the delicate and soulful delivery of George Michael, the Alumine Two.Five allows the listener to fully appreciate the nuances and emotional content of the vocal performance. Similarly, instruments in the midrange possess a natural and accurate timbre, further enhancing the sense of realism.

For a speaker of its size, the Alumine Two.Five delivers a surprisingly deep and well-defined bass foundation. The dual 6.5-inch woofers, working in concert with the front bass reflex port, provide a solid and impactful low-end that extends down to a claimed 35Hz. The bass is characterized by its definition and control, avoiding any sense of boominess or muddiness, and provides a firm anchor for the rest of the musical spectrum. Even with bass-heavy tracks, the Alumine Two.Five maintains its composure, delivering a powerful yet articulate low-end.

The Alumine Two.Five excels in creating a wide and deep soundstage with precise imaging capabilities. The speakers effectively disappear into the listening room, allowing the listener to easily pinpoint the location of individual instruments and performers within the sonic landscape. The imaging is often described as laser-focused, extending well beyond the physical boundaries of the speakers, creating an immersive and three-dimensional listening experience. Subtle details, such as the decay of a note or the ambience of the recording venue, are rendered with impressive clarity, further enhancing the sense of spatial realism.

In terms of dynamics, the Alumine Two.Five demonstrates an impressive ability to handle both subtle micro-dynamics and large-scale macro-dynamics. From the quietest passages to the loudest crescendos, the speakers maintain their composure, delivering the full dynamic range of the music without compression or distortion. This dynamic agility contributes significantly to the speaker's engaging and lifelike presentation, allowing the listener to fully appreciate the expressive nuances within the music. The high sensitivity of 93dB means that the Alumine Two.Five can be driven effectively by a wide range of amplifiers, including those with relatively low power outputs.

Overall, the Stenheim Alumine Two.Five offers a highly coherent and musical presentation. The seamless integration of the drivers, the neutral character of the aluminum cabinet, and the meticulous crossover design all contribute to a sound that is both accurate and engaging. The speakers have a remarkable ability to get out of the way and allow the listener to connect with the emotional intent of the music. The consistently positive reviews highlight the speaker's ability to draw listeners into the performance, making it a truly enjoyable and rewarding listening experience.

The Merits: Advantages of the Alumine Two.Five

Based on the analysis of various reviews, the Stenheim Alumine Two.Five exhibits several key strengths:

• Exceptional Clarity and Detail: The speaker retrieves a remarkable amount of detail across the entire frequency spectrum, allowing for a nuanced and revealing listening experience.
• Precise and Coherent Sound: The two-way design and high-quality crossover contribute to a seamless and integrated sonic presentation.
• Smooth and Extended High Frequencies: The silk dome tweeter delivers detailed and airy highs without any harshness or sibilance.
• Transparent and Natural Midrange: Vocals and instruments in the midrange sound remarkably natural and articulate.
• Deep and Well-Defined Bass: For its size, the speaker offers surprising bass extension with excellent definition and impact.
• Wide and Deep Soundstage with Precise Imaging: The Alumine Two.Five excels at creating a realistic and immersive spatial presentation.
• Excellent Dynamics and Resolution: The speaker handles both subtle and large dynamic swings with ease and without distortion.
• Minimal Enclosure Vibration and Coloration: The aluminum cabinet provides a stable and inert platform, minimizing unwanted resonances and preserving the purity of the sound.
• Room-Friendly Size and Placement: The relatively compact dimensions and front-ported design allow for easier integration into various listening environments.
• High Sensitivity and Easy to Drive: The speaker can be effectively powered by a wide range of amplifiers, including low-powered tube amps.
• High Build Quality and Elegant Design: The aluminum construction and minimalist aesthetic exude quality and sophistication.

Points to Consider: Potential Drawbacks

While the Stenheim Alumine Two.Five has received overwhelmingly positive reviews, there are a few potential drawbacks to consider:

• Price: As a high-end loudspeaker, the Alumine Two.Five represents a significant investment, placing it outside the reach of many audiophiles.
• Stability: One reviewer noted that the speakers might not be as stable as some larger, more heavily built competitors, even with the included feet installed.
• Lack of Grilles: The speakers are currently shipped without grilles, which might be a concern for those with children or pets who could potentially damage the drivers.
• Minimalist Aesthetics (Subjective): While many appreciate the clean and understated design, some audiophiles might prefer a more traditional or visually ornate aesthetic.
  

  

Conclusion: A Worthy Contender in the High-End Arena

The Stenheim Alumine Two.Five stands as a remarkable achievement in loudspeaker design, successfully translating the core principles of the acclaimed Alumine Two bookshelf speaker into a floorstanding format with enhanced bass performance. Its meticulously engineered aluminum cabinet, carefully selected drivers, and sophisticated crossover network work in harmony to deliver a sonic experience characterized by exceptional clarity, detail, coherence, and dynamic agility. The overwhelmingly positive reception from respected audio publications underscores its status as a serious contender in the highly competitive high-end loudspeaker market.

While the Alumine Two.Five commands a premium price and presents a minimalist aesthetic that might not appeal to all, its sonic merits are undeniable. The speaker's ability to create a wide and immersive soundstage, reproduce music with natural tonality, and handle both delicate nuances and powerful crescendos with aplomb makes it a compelling option for discerning audiophiles seeking a truly engaging and rewarding listening experience. Despite minor considerations such as stability and the absence of grilles, the Stenheim Alumine Two.Five undoubtedly lives up to its heritage and the accolades it has received, solidifying its position as a new icon in the world of high-performance floorstanding loudspeakers. For those seeking a loudspeaker that prioritizes sonic purity, accuracy, and musicality in a stylish and relatively compact form factor, the Stenheim Alumine Two.Five warrants serious consideration.