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Anything to say on Speakons
On 7/21/2020 6:50 AM, Phil Allison wrote:
Note: The internal symmetry of a co-ax cable is the secret to its excellent mag field rejection. Equal and opposite currents inject into the core and shield from a nearby AC mag field - so complete self cancellation. The ONLY real advantage of a 2 wire "balanced" mic line is when used for carrying phantom power to a mic or device that needs it ( eg a DI unit). With the assumption that the input is differential, what you're losing is common mode rejection. You're relying on the construction of the coax to be all you need to keep EMI from getting to the destination through the cable. A differential input fed from an accurately balanced source is like "belt and suspenders." A lot of the "unbalanced hums" netlore is a function of improper grounding and shielding in the source and destination devices. Much of this has been sorted out since the AES devoted a whole issue of the Journal in 1975 to ways to build stuff right so you don't get EMI picked up by the cable shield to the guts of the destination device via a current path through what's supposed to be "ground." -- For a good time, call http://mikeriversaudio.wordpress.com |