Wednesday, December 12, 2007
Spot the Blooper
Astatic is an old and highly venerated microphone company that virtually invented the communications microphone industry. Its D-104 Microphone is emblematic in a way that only mics like the RCA 77DX and very few others have attained.
Here is a link to more about the Astatic D-104, with further links to the history of this fine company.
Sometimes errors occur. In the October 2007 issue of Sound Communications is this advert for Astatic's neat variable pattern lectern microphone. These slim devices are the preferred transducer for businessmen and women who want a no-nonsense and inconspicuous device at the speaker's post. The small electret condenser type microphone with its easily EQ'd flat output is nearly ideal for this application, where high intelligibility, low noise, and high RF rejection are key selling features. Other makers advertising such ware include Sennheiser and beyerdynamic, with nearly identical ads, each showing a threatening, RFI-emitting cellphone in near proximity. These companies know all too well the importance of aggressive RFI shielding which has become even more difficult with multiple frequency personal communications devices only inches away. You see, even when not being used, cellular phones "poll", which is a term used to send the identification number to the cellular system, to let it know it is there. That way the system operator can keep track of who is in the particular cell of the network and automatically route calls in to that cellphone. This can happen many times per minute, and the on-off nature of digital RF devices produce plenty of pulse-type emission, some which can be detected by poorly shielded microphones.
Astatic, Sennheiser, and beyerdynamic (no capital letter needed, I was politely informed) have apparently solved the problem. That's good, because it suggests that some of the high end makers of studio recording mics may have solutions available to them, since, unfortunately, not all RFI ingress problems in studio recording have been completely eliminated.
Posted by Bob Crowley at 3:30 PM