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Bang & Olufsen BM5/ BM6 user reviews
Tonmeister D's review (This content has been automatically translated from French)
Bang & Olufsen BM5/ BM6
Stereo ribbon mic 60s in Blumlein technique (two-way crossover).
Frequency Response 30Hz to 13kHz + / - 3dB. Impedance of 150Ω is a load of easy preamp.
Top cap can rotate from 0 to 90 degrees (with a little more leeway).
There is a 3-way switch polarity (+ / 0 = no output / -) and a high-pass filter (M = linear, T = mild decrease of-10dB @ 100Hz relative to 1 kHz).
Output is via a small-Tuchel 5 pin connector, and a spherical hinge joint allows some movement for optimum positioning.
I bought this mic a studio "vintage" in Britain. When he arrived, only the lower band was working ... even in this poor condition, two characteristics of this microphone was immediately evident on the test: the sound smooth and rich, and its notoriously low output. We speak +80 dB of gain necessary to get a decent recording level, and not many preamps are able to provide that much without noise.
Coincidentally, those who can are very very expensive, with the exception of the AEA TRP designed by Fred Forssell.
Anyway, as the upper band was shattered, I sent the tapes specialist Dr Stewart Taverner (Xaudia) that has ribbons and changed OUR old magnets for new custom that give about 20dB emerged stronger while keeping the original tonal character. I recommend this update because it is much cheaper than buying a new preamp.
Remember, even after this treatment, you still need 60 dB of clean gain to record low level sources, such as acoustic guitar or mandolin fingers.
But you can do, and what his brother you get! This mic is located between the black velvet and Coles 4038 and the greater presence of Beyer M160. A very smooth high fidelity of, perfect for stereo recording horn sections, string quartet, retro drums, tuned percussion (vibraphone to balafon to dulcimer), acoustic guitar, etc..
Of course, nothing prevents you to use it as a mono microphone. I think it really stands out on solo strings: violin, cello, Cretan lyre, Turkish kemence, etc.. Just yesterday I recorded a well-known young violinist and was quite stunned by the tone very class we could capture his violin.
All-in-all a very nice microphone with superior sound quality.
But we must be aware of its shortcomings: the very low output (plugin preamps such as Triton Fethead may be useful here), fragility (especially small switches and ring that connects the upper capsule microphone body) and the need for good acoustics of the room, being a Blumlein case.