DIYRM / Scott Hinson Multiple Entry Horn build

[-Matt-]

The dictionary definition of "error" is a "mistake". Unless we are talking about Danny Ritchie, or Zu Audio, or someone else who doesn't take measurements, then it is NOT an error, it is a tradeoff chosen by the speaker designer. It would be much more appropriate to simply refer to it as a directivity "mismatch" which is just a factual statement without any judgmental connotation.

...It is a disservice to suggest to them that basic design decisions are "mistakes".

In scientific writing the term error does not usually imply a mistake (eg by the designer in this case). Error is the difference (calculated by subtraction) between a measured value and a hypothetical ideal target. Or the difference between a prediction and the actual result. In curve fitting, for example, it is common to calculate the SSE (sum of squared errors) as a measure of GOF (goodness of fit).

 

[a4eaudio]

In scientific writing the term error does not usually imply a mistake (eg by the designer in this case). Error is the difference (calculated by subtraction) between a measured value and a hypothetical ideal target. ...

Yes, I know. But that is not how the term " directivity error" is used, or at least I have never seen it used that way on ASR.

 

[bmc0]

It would be much more appropriate to simply refer to it as a directivity "mismatch"

To me, that term is more apt for, say, a woofer and tweeter with significantly different directivity near their crossover point.
Fundamentally, the "waistbanding" effect in question is due to diffraction.