Mic Archive
Coles 4038
Photo: Audio Engineering Associates, from its aea sheet rh, p. 1.

Coles Electroacoustics

Coles 4038

Ribbon, figure-8 (BBC design), passive

Approximate Some readings for this mic are uncertain; see the graphs.

Type
Ribbon
Pattern
Figure-8
Sensitivity
−65 dBV/Pa
Max SPL
125 dB SPL
Impedance
300 Ω
Rated range
30 – 15k Hz

Frequency response

Angle
Distance

Frequency response: from the spec sheet, p. 1. Untitled graph under "Frequency response 30 Hz to 15,000 Hz"; 0 dB = "-85db ref 1volt/dyne/cm² at 30Ω". "All microphones factory tested in free field conditions." Distance and smoothing not stated. Approximate reading error up to about 1 dB.

Independent measurement: also drawn, from the Multi-Angle, Multi-Distance Microphone Impulse Response Dataset (Juan Carlos Franco Hernández, Bogdan Bacila, Tim Brookes, Enzo De Sena, University of Surrey) (CC BY 4.0): one unit, measured at 1.25 m and set to 0 dB at 1 kHz, from 136 Hz up. Not the manufacturer's curve.

Dashed: outside the rated range, or simulated (other angles and distances). Hover or tap the graphs for values.

Polar pattern

Polar pattern: from the stc leaflet rh, p. 4. Fig. 2 "Horizontal" (sketch beside it: 0° front, 90° and 270° to the sides, 180° rear). Rings every 4 dB, "dB relative to 0° response"; frequency range per line as labelled; measuring conditions not stated. Approximate reading error up to about 1 dB; some frequencies are identified by reasoning, not by the legend: 50 Hz, 5k Hz, 10k Hz.

Compare with other mics

All specs

From the spec sheet
Sensitivity−65 dBV/Pa. "-65 dB W.R.T. 1V/Pa". The 1961 STC leaflet gives -85 dB re 1 V per microbar (the same) for the 30 ohm 4038-A.p. 1
Max SPL125 dB SPL, less than 1% distortion; frequency not stated. AEA: the 1% third-harmonic point is 165 dB SPL at 1 kHz, 125 dB at 110 Hz and 110 dB at 55 Hz.
Output impedance300 ohm. The 1961 4038-A was 30 ohm nominal.
Rated frequency range30 Hz to 15 kHz. The AEA sheet says 30 to 20,000 Hz.
Connector4069 3-pin jack plug (Western Electric type). "Pin 1 positive - Pin 2 negative - Pin 3 screen"; AEA: "Western Electric type 4069".
Weight1080 g. "2 lb. 6 oz. (1.08 Kg)".
Dimensions197 × 83 × 61 mm
Supplied accessories4070 floor stand plug adaptor; 4071 mic to stand adaptor with XLR; 4069 to XLR; soft cloth bag; foam-lined case
Hum rejectionHum-neutralising wiring and a shielded toroidal transformer: 30 to 40 dB reduction of stray magnetic fields
BodyHeavy-gauge perforated brass backed by monel mesh; hinge tilts 90°; black stove enamel
From the stc leaflet rh
OriginBBC design; the 1961 leaflet is from Standard Telephones and Cables, made "by agreement with the British Broadcasting Corporation"p. 2

Documents

Copies kept by Mic Archive, because manufacturers move and drop their documents. Each is © Coles Electroacoustics, unchanged, with its original address.

Product page on coleselectroacoustics.comRecording Hacks

Recommended for

Instruments whose sources name this mic, or an earlier version or variant of it.

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