Bang & Olufsen Penta Mk2 (1978)

The Bang & Olufsen Penta Mk2, introduced in 1978, stands as a landmark in high-fidelity speaker design. Part of B&O’s innovative Penta series, the Mk2 iteration refined the original concept with improved acoustic performance and build quality. Celebrated for its minimalist Scandinavian design and modular construction, the Penta Mk2 exemplifies Bang & Olufsen’s commitment to merging aesthetic elegance with acoustic precision.

Specifications

Feature	Specification
Year of Production	1978–1982
Power Handling	60W RMS per channel
Impedance	4 ohms
Sensitivity	86 dB
Frequency Response	45 Hz – 20 kHz (approximate)
Tweeter	1" dome with Acoustic Lens technology
Woofer	2 x 6.5" woofers (one per column)
Crossover	Adjustable passive network, 2.5 kHz nominal
Enclosure	Modular columns, beech wood construction
Placement	Wall-mountable or stand-mounted
Dimensions (H×W×D)	95 cm × 22 cm × 22 cm per column
Weight	12 kg per column

Design and Key Features

The Penta Mk2 features a striking modular design, consisting of two separate vertical columns—one housing the woofer and the other the tweeter. This separation was engineered to improve stereo imaging and reduce inter-driver interference. Each column is crafted from solid beech wood, contributing to both visual warmth and acoustic damping.

The Acoustic Lens tweeter is a hallmark of B&O’s innovation, designed to disperse high frequencies evenly across a wide listening area, minimizing the "sweet spot" limitation common in conventional tweeters. The lens creates a smooth off-axis response, delivering consistent clarity throughout the room.

An adjustable crossover network allows users to fine-tune the tonal balance, particularly useful when adapting the speakers to different room acoustics or personal preferences. The system is designed to be wall-mountable, reinforcing its integration into modern living spaces—a core tenet of B&O’s design philosophy.

Sound Signature

The Penta Mk2 delivers a neutral and precise sound profile. Highs are exceptionally clear and detailed, thanks to the Acoustic Lens technology. The midrange is well-balanced, making vocals and acoustic instruments sound natural and present. Bass is tight and controlled, though modest due to the sealed enclosure design and 45 Hz lower limit—best suited for smaller to medium-sized rooms.

Imaging is excellent, with a wide and stable soundstage, a result of the vertical driver separation and time-aligned crossover. While not bass-heavy, the Penta Mk2 excels in musical accuracy and tonal coherence, ideal for jazz, classical, and vocal-centric genres.

Historical Significance

The Penta Mk2 emerged during a period of bold experimentation at Bang & Olufsen. As part of the Penta series, it pioneered the modular speaker concept, challenging traditional cabinet designs. Its minimalist aesthetic—free of grilles, with clean lines and natural wood—reflected the Danish modernist movement and set a precedent for future B&O products.

The speaker became a symbol of luxury hi-fi in the late 1970s and early 1980s, often featured in architect-designed homes and high-end audio showrooms. Its design was as much a statement of lifestyle as it was of audio performance.

Maintenance and Restoration Tips

Due to their age, Penta Mk2 speakers often require maintenance to restore optimal performance:

Foam Surround Replacement: The original foam surrounds on the woofers are prone to disintegration after 40+ years. Re-coning or replacing with modern rubber surrounds is highly recommended.
Crossover Capacitors: Electrolytic capacitors in the crossover network degrade over time, leading to muffled sound or imbalance. Replacing these with modern film capacitors improves clarity and reliability.
Wiring and Connectors: Check for corrosion on binding posts and internal wiring. Clean or replace as needed to ensure solid electrical contact.
Wood Finish Care: Clean beech wood columns with a soft, dry cloth. Avoid harsh chemicals; use wood conditioner sparingly to restore luster.
Mounting Hardware: If wall-mounting, ensure brackets are secure and compatible with modern standards.

Restored pairs in original condition are highly sought after and can command premium prices in the vintage audio market.

Collectibility and Market Value

The Bang & Olufsen Penta Mk2 holds a collectibility rating of 7/10. Its iconic design, historical relevance, and association with B&O’s golden era make it a desirable piece for audiophiles and design collectors alike.

As of 2024, a pair of Penta Mk2 speakers typically sells for $300–$600, depending on condition, originality, and restoration quality. Fully restored units with upgraded components and preserved wood finishes tend to reach the higher end of the range. Original packaging or accessories can further increase value.

Conclusion

The Bang & Olufsen Penta Mk2 remains a testament to the fusion of form and function in high-end audio. More than just speakers, they are design artifacts from a pivotal moment in audio history. With proper care and restoration, the Penta Mk2 continues to deliver a listening experience that is as emotionally engaging as it is technically refined—proving that great design is truly timeless.