Originally Posted by hawkster27
What exactly is a "calibrated mic"? Calibrated to what? I've had good luck with the Audyssey plastic mic and a tripod. But I also have a "real" Sony mic from back in the day. (It's stereo, but I have a mono adapter.) Would that be better? Worse? The same?
How a microphone is "calibrated" depends usually on the institution, which does it.
To my knowledge Audyssey did not do any microphone calibrations, but acquired a "calibrated" microphone from a supplier for its no longer sold
Many calibrators use a pre-calibrated microphone as a reference and measure a well defined sound source against it. Then use the same procedure to measure an unknown microphone and print out the differences (file and / or graph). This might be done at the end of the production process or individually afterwards. If the results are really trustworthy
depends on the supplier or calibrator, his "reference standard" and his calibration procedure. Some "calibrations" especially in mass production processes (low cost) are only done for some samples of a batch...
Microphones and their materials used age, thus their frequency response changes to some degree over time. Calibrated microphones have to be re-calibrated after certain periods of time, because they not only age (and tolerances inevitably increase) but are sensitive to handling problems too.
A "really good measurement" microphone is usually not that cheap, because it is adjusted individually already during assembly for tight (and well documented) tolerances (a time consuming and labour intensive process) and measured again afterwards. The individual graphs / file are provided as a reference. They usually cost several hundred $$$.
If it really makes an audible
difference using a "calibrated" microphone for measurements in comparison to the supplied standard microphone in ones own home is up to the individual user considering those imminent problems which usually exist in this environment and not considering any problems / errors of the individual measurement process.
The standard Audyssey microphone i.e. is specified by Audyssey as having typical tolerances (deviations) of max. "+/- 2db" against an (unspecified) reference. Some replacement Audyssey mikes sold on Ebay are known to be "fakes" of unknown quality...
The conclusion: Some prefer it, some doubt it...