Bang & Olufsen BM2
Manufacturer:
Bang & OlufsenModel:
BM2Country of Manufacture:
DenmarkMicrophone Type:
RibbonPolar Pattern:
Figure 8Production Start Year:
1951Production End Year:
1960Rarity:
4
Technical Description:
The BM2 is a handsome microphone, with a very different look to the later mics. It has a cast metal body and folded, chromed brass grill. The mics were painted in a green-yellow textured paint, which looks better than that sounds. The ribbon is held in a removable frame, which slides out for servicing.
The BM2 was made from 1951, and was replaced by the very different looking BM3 in 1960. Although different in appearance, the motor assembly and ribbon are similar in both cases with a long broad pistonic style ribbon between two alnico magnets. The ribbon dimensions in our example measured 50 mm long by 5 mm wide.
The switch on the front of the microphone is marked M and T, for Music and Talk. This switches an inductor in parallel with the output transformer, which has the effect of reducing the bass response below 100 Hz to compensate for proximity effect when used up close to the speaker.
The output impedance is 50 ohms.
