Test equipment (reference-standard microphones)
As I mentioned recently, we have recently invested several thousand dollars in new test equipment. Although Bruel & Kjaer has always been at the heart of our test set, we have not had the luxury of duplication across the various sites that I may need to measure speakers: on the production line, in the test bunker (for grading drive units), at the Old Dairy (open space for measuing) or The Stable (mini deadroom) or at home. I have made do with 'clone' amateur test equipment - especially microphones, and that has introduced a degree of uncertainly which has wasted valuable time.
So, back to B&K, the best, the most accurate, with traceable standards and a very long life. For example, here is the actual curve (also supplied as a mini-CD) for the best of the new microphone capsules we have just purchased from B&K Denmark http://www.bksv.com/.
As you can see from the curve below the yellow zone reresents +/- 1dB, and this specimen deviates from perfectly flat by a maximum of only about 0.5dB at the very highest frequencies and is, for all practical purpsoses, perfect. Bigger picture here: http://www.harbeth.co.uk/images/B&Krefmic640.png
An accurate microphone, a reliable and known acoustic space - even if not a perfelcty relection free one, and a flat amplifier (another sad story) are paramount should you wish to design quality speaker systems.
We now meet our ISO9001 obligations in this important area.
Alan A. Shaw
Harbeth Audio UK