@erik_squires asked:
" Lets say there is a speaker with good forward and poor off-axis response. How do you suggest an audiophile discover this with no tools but their ears?"
Excellent question!
First, make your best estimate of what frequency region has a problem.
Second, look at the drivers and crossover points to see if there seems to be a correspondence with the problematic frequency region(s). Typically a direct-radiating speaker has extra-wide response at the bottom end of a driver’s frequency range (like at the bottom end of the tweeter’s range), and relatively narrow response at the top end of a driver’s range (like at the top end of the midwoofer’s range, and again at the top end of a dome tweeter’s range). Given that frequency response peaks are more likely to be audible (and objectionable) than frequency response dips, audible off-axis anomalies are most likely to be associated with the bottom end of a driver’s range.
Third, do YOUR suggested test to see if the "predicted" off-axis anomaly disappears in the nearfield.
This isn’t ironclad proof of course, but imo it can add up to an "educated guess".
Finally, here is a way to test the room independent of the speakers: With no music playing, walk from room to room in your house, speaking out loud and listening to the timbre of your voice. It is best to do this when nobody else is around; people tend to get the wrong idea. The other rooms are to give you some baselines; pay particular attention to the timbral quality of your voice in your listening room. IF you hear a timbral skewing which corresponds to the anomaly you hear when your speakers are playing, then the room is at least PART of the problem and may well be the ENTIRE problem. But if your voice sounds good and natural in your listening room, that points to the speakers (or sometimes something else in the signal chain) as the primary culprit.
Duke
