Some folks listen on axis and some loudspeakers are designed to be used this way, so a blanket statement that we don’t listen on-axis, is not totally correct. However, the bulk of this post is!!
What is flat?
How can flat-measuring loudspeakers sound different?
And for that matter, how can same-measuring-anything sound different?
The answer lies in a couple of areas. First, we do not measure all parameters that impact sound quality. In fact, as you will see below, we miss some of the most important opportunities for quantifying performance.
Second, even if we could measure everything how much weight do we assign to each parameter?
So the two things worth considering: what is it we’re measuring, and how much do measured differences matter?
Consider speaker crossover design. When matching a midrange driver to a tweeter, it is often the case the midrange driver has to be phase inverted for best performance. How many of us might wince at the idea one of three drivers in your speakers is out of phase? And yet, that is often the case.
And then we move on to perhaps the most important aspect of them all. What and how are we measuring response?
Loudspeakers are measured on axis (facing directly at the speaker).
We do not listen on axis. So perhaps a more important measurement is how smooth is the off-axis response?
Would it make more sense to publish measurements at the listening position?
Should we publish stereo measurements from the listening position?
Lots to unpack here and lots more to think about.
Flat measurements are a myth.
A flat-sounding system is when playback sounds like music and not HiFi.