Kohji Matsubayashi (松林弘治)

Things I learned on Phono EQ curves, Pt. 17

EQカーブの歴史、ディスク録音の歴史を学ぶ本シリーズ。前回 Pt.16 では、第二次世界大戦勃発に端を発した物資不足から「サファイア・グループ」という業界エンジニア交流コミュニティが生まれ、企業秘密による競争から業界をあげての情報公開・技術標準化への動きがうまれたことを学びました。

On the previous part 16, I learned on the history of the “Sapphire Club” aka “Sapphire Group”, that was formed during the WWII because of the shortage of industry materials, and led the standardization in the industry, from the competition with trade secrets to the open collaborations, especially among the engineers.

同時に、その「サファイア・グループ」をきっかけとして、戦後の Audio Engineering 誌の発刊、およびオーディオ工学専門学会 Audio Engineering Society の誕生に繋がった流れを学びました。最後に、初の統一再生カーブである「AES 標準再生カーブ」について詳細を学びました。

At the same time, I learned the foundation of the Audio Engineering magazine as well as the Audio Engineering Soeicty, as a result of collaboration through the Sapphire Group. Then I learned the details of the “AES Standard Playback Curve”, the first advocated standard characteristic for commercial records.

調査に手間取るなどして少し間があいてしまいましたが、今回の Pt.17 では、LP黎明期〜AES標準再生カーブ発表の1951年1月〜統一前夜(最終的に米国各業界内で統一がなされる 1953 NARTB / 1954 改訂 AES / 1954 RIAA 策定の直前)、までの状況を調べていきます。めちゃくちゃ長い記事になってしまいました(笑)

This time as Pt. 17, after a few months of absence (due to the continuous research etc.), I am going to continue learning the history of disc recording, especially during the period: from the advent of LP records, publication of the AES curve in Jan. 1951, to the eve of the industry standardization (formations of 1953 NARTB / 1954 new AES / 1954 RIAA). Please note, this part is going to be an extraordinarily lengthy article 🙂

Mercury MG-50000 Rear Cover (AES)

“About This Recording…” section of Mercury MG-50000 (1951), recommending AES playback curve.
Mercury MG-50000 (1951) の裏ジャケより。AES 再生カーブが指定されている。

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Kohji Matsubayashi (松林弘治)

Things I learned on Phono EQ curves, Pt. 16

EQカーブの歴史、ディスク録音の歴史を学ぶ本シリーズ。前回 Pt.15 では、こぼれ話的に「ハイ・フィデリティ」という用語の歴史について調べてみました。

On the previous part 15, I studied on the history of the term “High Fidelity (Hi-Fi)” as a side story, before I continue studying more on the history of disc recording and recording / reproducing EQ curves.

今回の Pt.16 は、再び本論に戻り、オーディオ工学に特化した学会の設立、そしてその学会から出された「統一再生カーブ」の提唱、などをみていきます。

This time as Pt. 16, I am going back to continue learning the history of disc recording, including the establishment of an academic society specialized in audio engineering; and the proposed playback curve advocated by that society.

Hollywood Sapphire Group

source: “Hollywood Sapphire Group”, Robert J. Callen, Audio Engineering Magazine, Vol.32, No.1, January 1948, pp.17,39-41.
1946年2月13日、Hollywood の Brittingham’s レストランで模様された、Hollywood Sapphire Group の初会合の写真 (写真キャプションの1947年は間違い)

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Kohji Matsubayashi (松林弘治)

Things I learned on Phono EQ curves, Pt. 15

EQカーブの歴史、ディスク録音の歴史を学ぶ本シリーズ。前回 Pt.14 では、1949年〜1950年(または1951年)の「回転数競争」における、各レーベルの参入状況を時系列に追ってみました。

On the previous part 14, I studied more on the history and chronology of which label joined which new format (33 1/3 rpm or 45 rpm) during the so-called “The Battle of The Speeds” era in 1949 to 1950 or 1951.

今回の Pt.15 はその続きなのですが、一休みして、1950年頃からの「ハイファイ」ブームの黎明期よりずっと前に生まれた、「ハイ・フィデリティ」という用語の歴史についてみていきます。

This time as Pt. 15, before I am going to continue learning the history of disc recording, I will look into the side story — i.e. the pre-history of the “Hi-Fi craze”, as well as the history of the term “High Fidelity” itself.

RCA Photophone High FIdelity (1935)

source: RCA Ad, Kinematograph Weekly, June 27, 1935, p. 76.
1935年の英国雑誌に登場した、RCA Photophone High Fidelity の広告

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Kohji Matsubayashi (松林弘治)

Things I learned on Phono EQ curves, Pt. 4

前回 は、大恐慌時代の1930年代前半、WE特許使用料回避のため生まれたBlumleinシステムや、当時のRCA VictorやColumbiaの状況など、あれこれについて調べました。

On the previous part, I studied on the history of the improvement of disc recording technology for commercial discs, including the Blumlein system, situations of RCA Victor and Columbia in the 1930s (during the Great Depression), etc.

今回は、民生用ではなく、映画用・放送局向けのレコード技術 の話、そして初めてS/N比向上の目的で 意識的に高域プリエンファシスが用いられた録音技術 について学んでいきます。

This time, I am going to continue learning the history, from the disc recording technology for professional talking motion pictures and broadcast stations (not regular records for consumer market), and the very important technology that consiously used treble pre-emphasis for the first time in history, to increase S/N ratio.

Vertical cutting vs Lateral cutting (Read, 1952)

source: “The Recording and Reproduction of Sound”, Oliver Read, 2nd Edition, 1952, p.21, Fig. 3-3B.
縦振動記録(左)と横振動記録(右)の比較

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Kohji Matsubayashi (松林弘治)

Things I learned on Phono EQ curves, Pt. 3

前回 は、電気録音黎明期のあれこれについて調べました。今回は、その後発展していく電気録音、そして 1930年前後の各レーベルの状況 について引き続き調べていきます。

On the previous part, I studied on more of the history of Electrical Recording in its very early years, along with several digressions… This time, I am going to continue learning the evolution of the electrical recording, as well as the situation of record labels around the 1930s.

American Epic; Recording The {Twenties, Thirties} Read More / 続きを読む
Kohji Matsubayashi (松林弘治)

Things I learned on Phono EQ curves, Pt. 2

Pt.0 (はじめに)」、そして「Pt.1 (定速度と定振幅、電気録音黎明期)」の続きです。

This article is a sequel to “Things I learned on Phono EQ curves, Pt.0” and “Things I learned on Phono EQ curves, Pt.1”.

前回 は、いろいろ脱線しながら(笑)レコードに記録される2つの特性と、電気録音黎明期のあれこれについて調べました。今回は、EQカーブの話を離れて、電気録音黎明期のあれこれ についてもう少し調べていきます。

On the previous part, I studied on two recording characteristics (constant velocity and constant amplitude), as well as the history of Electrical Recording in its very early years, along with several digressions… This time, I am going to continue learning other things during the early days of electrical recording, apart from EQ curves.

Brunswick Panatrope Ad, The Talking Machine World, Feb. 15, 1927, p.5

source: Brunswick Panatrope Ad on “The Talking Machine World, February 15, 1927”, p.5.

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Kohji Matsubayashi (松林弘治)

Things I learned on Phono EQ curves, Pt. 1

Pt.0 (はじめに) の続きです。

This article is a sequel to “Things I learned on Phono EQ curves, Pt.0”.

レコードのEQカーブについて深掘りする前に、そもそも なぜイコライゼーションが生まれたのか、なぜ必要とされたのか、その歴史から調べてみることにしました。また、更にさかのぼって、音を溝に記録するとはどういうことか、についても学び直すことにしました。なので、カーブの話に到達するまでに長い道のりになってしまう予定です(笑)

Before digging deeper about EQ curves, I started to study from the very beginning: why the EQ curve was born, why it was/is needed for phonograph recording (and playback). Also, I tried to re-study the very basic – how the recording sounds are converted to a modulated spiral groove. So I’m afraid it will take very long before I reach the story of the EQ curve itself…

Digital image of the surface of 78 rpm record taken with optical magnification. The illumination is coaxial (the light falls vertically onto horizontal record), therefore only horizontal parts of the record reflect the light back into the optical system. These include the inter-groove surface of the record represented by the wide bands in the picture, and the bottom portion of the groove, represented by the thin lines. The scratches on the inter-groove surface are clearly seen. The size of the imaged surface is 2.35 x 2.19 mm 2 .

Audio Reconstruction of Mechanically Recorded Sound by Digital Processing of Metrological Data – Scientific Figure on ResearchGate.
Available from: https://www.researchgate.net/figure/Digital-image-of-the-surface-of-78-rpm-record-taken-with-optical-magnification-The_fig1_242606860 (accessed 4 Sep, 2022)

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Kohji Matsubayashi (松林弘治)

Things I learned on Phono EQ curves, Pt. 0

以下、持論・異論・珍説が飛び交う、議論多き「フォノEQカーブ」について、1920年代電気録音黎明期にまで歴史を遡り、録音・再生カーブのみならず、ディスク録音全般について、正しく理解するために勉強した軌跡です。長編になります。

Following is just the beginning of the long series of the study I have been doing for a while, regarding the controversial topic “Phono EQ Curves” – people having various opinions on it, although many of them are subjective and not scientifical. I started the study and research of the history of disc recording as a whole, from the very early electrical disc recording technology in the 1920s.

我が家では15年ほど前から、78rpm や非RIAA LP用に Esoteric Sound (Rek-o-kut) Re-Equalizer という簡易式アドオン型フォノイコライザを使用しています。実は昨年、Re-Equalizer III という最新バージョンに置き換えたのですが。

Since 2006, I’ve been using Esoteric Sound (Rek-o-kut) Re-Equalizer (actually I replaced it with the most recent version Re-Equalizer III in 2021) for 78rpms and pre-RIAA LPs. It’s a niche phono EQ compensator.

Esoteric Sound Re-Equalizer

Esoteric Sound Re-Equalizer III (above), bought in 2021
Esoteric Sound Re-Equalizer (bottom), bought in 2006

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