American D4
Manufacturer:
AmericanModel:
D4Country of Manufacture:
AmericanMicrophone Type:
DynamicPolar Pattern:
OmnidirectionalProduction Start Year:
1942Production End Year:
1959Rarity:
2
Audio Recording:
Nylon string guitar recorded with the American D4 dynamic microphone.
Multiple quality options available
Microphone History:
The American D4T was advertised in the Lafayette catalogue in 1942. The D4 and D4T models appear in the Radio Masters 1944 catalogue (10th edition). These microphones had a long production period and were still in the RM catalogue in 1959.
Bob Hope used a D4 or D4T in many of his USO (United Services Overseas) concerts. The picture above is at Pearl Harbor in 1944, curtesy of wikicommons.
Technical Description:
MoMics note:
The D4 and D4T are essentially the same microphone but with different output impedances. The 'T' in the name may have denoted the presence of an output transformer - the D4T was available with different impedances - 200, 500, or 38,000 ohms - whereas the D4 had a standard 30 to 50 ohm output, typical of a direct connection to a moving coil dynamic microphone. The list price in 1944 for the D4 was US$18, and the D4T was $20.
Our own frequency response measurements are below. The red line is on axis and the green line is with the microphone pointing upwards, at 90 degrees to the sound source.
From an advertisement in the Radio Masters Catalogue, 1944
A QUALITY. LOW-PRICED, MOVING-COIL MICROPHONE. For general use where clear speech and natural music reproduction is required. This new AMERICAN microphone is a very efficient instrument. having a broad range, from 60 to 7500 Hz., and high output of -56 db (0 db=] v/bar). The utility value lies not only in the quality and type of response but also in mechanical features, such as light weight (approximately 10½ oz.), a full 180° vertical angular setting, and positive friction lock at the swivel.
The D4T, high impedance, is equipped with a single-contact, shielded plug. The 50, 200 and 500 ohm models are equipped with a two-conductor plug and have a balanced line out.
The D4 model is of voice-coil impedance, approximately 30 ohms. Lines up to several hundred feet may be used on all models except the high impedance, where line should be restricted.
The complete assembly includes 12½ feet of shielded, rubber-covered cable and shielded plug. Finished in platinum chrome.
Frequency Response:
