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, 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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