Diatone
A legendary speaker brand that was the pride of Mitsubishi Electric. Made famous with the NHK monitor speaker P-610, they built an era with the DS series utilizing advanced materials like boron and aramid. While their technical prowess is still spoken of today, after withdrawing from the consumer market in 1999, they now remain limited to high-end car audio and limited ultra-luxury speaker production. Their past glory was immense, but current limited activities and ultra-high price strategy complicate their evaluation.
Overview
Diatone is a high-end audio brand that was, and still is to a limited extent, developed by Mitsubishi Electric. With a brilliant history particularly in the speaker field, the full-range unit “P-610” developed in 1958 was adopted as NHK’s monitor speaker for many years, becoming legendary under the nickname “Rokuha” (Six-and-a-half). In the consumer market, they dominated the audio boom with the “DS series” that adopted cutting-edge materials like boron (B₄C) and aramid honeycomb for diaphragms. Their accurate and high-speed sound, backed by high technical capability, fascinated many audiophiles. Although they withdrew from the consumer market once in 1999, they currently maintain their lineage through ultra-luxury speakers like anniversary models and the car audio field.
Scientific Validity
\[\Large \text{1.0}\]Diatone’s product development was always guided by scientific and engineering approaches. Their pursuit of diaphragm materials was particularly thorough, continuously seeking materials with the best physical properties conceivable at the time (lightweight, high rigidity, moderate internal loss) to achieve ideal piston motion. The adoption of materials like boron, aramid honeycomb, and PAN-based carbon fiber were all choices backed by measurement data, and the resulting low-distortion, high-speed sound proves the correctness of their scientific development stance. With absolutely no occult elements, their product creation faithful to physical principles deserves the highest rating.
Technology Level
\[\Large \text{0.9}\]They created numerous innovative technologies to maximize unit performance, such as the unique D.U.D. (Diaphragm Unified with Dome) structure and D.M. (Direct Mount) system. Particularly, the diaphragm manufacturing technology that plasma-jet sprays and integrates boron onto a titanium base was extremely advanced, unmatched by competitors. In enclosure design as well, they invested advanced technology based on scientific knowledge, such as distributed resonance structures utilizing modal analysis. These technologies remain unfaded and can be called monuments in Japan’s speaker technology history. However, since current technology development is limited, they don’t reach a perfect score.
Cost-Performance
\[\Large \text{0.2}\]The past DS series boasted high cost-performance with relatively affordable pricing for their high performance. However, current Diatone focuses on ultra-luxury models like anniversary editions. For example, the 70th anniversary model “DS-4NB70” (approximately USD 12,470 per pair), while its technical value is recognized, has an extremely high absolute price. Speakers achieving equivalent or better frequency response and low distortion exist at much lower price points. For example, compared to the Revel PerformaBe F226Be (approximately USD 4,670 per pair) which boasts excellent measurement performance, CP = USD 4,670 ÷ USD 12,470 ≈ 0.37. Considering that many more affordable high-performance products exist, current Diatone products’ cost-performance must be evaluated as extremely low according to review policy.
Reliability & Support
\[\Large \text{0.6}\]The parent company Mitsubishi Electric’s quality control standards are very high, and past products had a reputation for durability. Even now, there are countless examples of DS series from decades ago being carefully used. However, with the 1999 withdrawal from the consumer market, the support system effectively ceased. Support for the current limited product lineup is provided by Mitsubishi Electric, but comprehensive support for the vast past product range cannot be expected. Considering this historical background, reliability evaluation must be limited.
Rationality of Design Philosophy
\[\Large \text{0.7}\]The design philosophy of pursuing “sound conversion faithful to input signals” and developing materials with excellent physical properties and optimal structures to achieve this goal is extremely rational. The approach to materials science and structural mechanics to achieve “fast sound” is particularly consistent and highly commendable. On the other hand, their overly strict design philosophy was sometimes criticized for sacrificing elements like musical “flexibility” and “richness of resonance.” Additionally, while the current ultra-high price, limited production business model may be rational from a technology pursuit perspective, it lacks rationality from the perspective of reaching more users.
Advice
Diatone speakers, especially the DS series traded in the vintage market, still hold much appeal.
- Suited for: Listeners seeking fast sound rise, clear sound image without bleeding, and monitor-like accuracy. Particularly for those who want to analytically listen to recording details, the DS series can be an excellent choice. If you can find units in good condition in the used market, you can discover value not found in modern speakers.
- Not suited for: Those who want to enjoy rich, warm resonance and relaxed musical groove. Also those who value manufacturer’s new product warranty and generous support. Current ultra-luxury models can be said to be products for enthusiastic brand fans and collectors.
Diatone is a brand that shines brilliantly in Japan’s audio history. While paying respect to its history and technology, it’s important to carefully assess condition when choosing used products.
(2025.07.05)