That simply can't be done technically with the very best pro

gear.



A-weighting doesn't help noise figures as the thermal Johnson noise of

the air rises with frequency. That's the datum for self noise. BTW I

heard it once as a young teenager in a windless grassland and after my

ears had settled down for over an hour. My heartbeat was loud and I

could hear my pulse and behind that was a very high hiss.



Beware of frequency response figures that don't quote +/- limits.

Beware of those which do, as the curves are frequently smoothed out.



As I said in my last email, above all, trust your ears first.



David



David Brinicombe

North Devon, UK

Cogito cogito ergo cogito sum - Ambrose Bierce