BSR RBM1
Manufacturer:
BSRModel:
RBM1Country of Manufacture:
United KingdomMicrophone Type:
RibbonPolar Pattern:
Figure 8Production Start Year:
1948Rarity:
5
Audio Recordings:
Speech (male) recorded using a BSR ribbon microphone with replacement transformer
Multiple quality options available
Speech (male) recorded using a BSR ribbon microphone with original transformer
Multiple quality options available
Microphone History:
'Dudley in the Past' website gives an excellent overview of the BSR company history.
Birmingham Sound Reproducers (BSR) was founded in 1932 by Daniel McLean McDonald in the West Midlands and became the world's largest manufacturer of record changers and tape decks by the 1960s. At its height, BSR had several manufacturing sites across the Midlands, in Cradley Heath, Stourbridge, and Old Hill.
Initially producing public address (PA) amplifiers and transformers, the company expanded into military electronics during World War II, helping develop early acoustic mine detonators and ASDIC sonar systems with Decca.
After the war, BSR shifted their production toward affordable record players Their "Monarch" automatic record changer dominated the market, featuring multi-speed capabilities and the ability to intermix records of different sizes. By 1977, the company was producing over 250,000 units a week, supplying mechanisms for famous household brands including Dansette.
BSR became a public company in 1957. In the end, BSR failed to anticipate the shift in technology to cassette tapes and digital formats and could not compete with cheaper import from the East. The company manufactured its final turntable in 1985.
Their is little direct information about their microphone production apart from one or two printed advertisments.
Technical Description:
From the manufacturer's advertisement:
RIBBON MICROPHONE R.B.M.1.
"A beautifully styled high fidelity ribbon microphone for Sound Recording and Public Address work. Finished in silver grey wrinkle with silver relief*. Special internal anti-vibration suspension and built-in 600 ohm line tranformer.
Sensitivity 0.13 millivolt/dyne cm2 open circuit."
*We have also seen examples in black wrinkle paint.
Note that the sound files and sweeps provided for this model are from restored microphones that have been fitted with new magnets and ribbons. One example (blue line) has an upgraded transformer and the other the original transfomer (red line).
Frequency Response:
Impulse Response Files:
Impluse Response file of the BSR ribbon microphone with new ribbon and original transformer.
BSR_Old_Xformer.wav
Impluse Response file of the BSR ribbon microphone. The transfomer in this microphone has been replaced.
BSR_new_Xformer.wav
