I see a people talking about imaging and sound stage but is there a way to these capabilities of an audio setup without actually testing them? Maybe something similar to a frequency response graph?
I am bot that knowledgeable about audio but isnt imaging/sound stage a function of audio resolution? As in the lowest frequency difference required to produce 2 signals without overlap? Can a measurement of peak width for outputs at single frequencies be an indication of resolving power?
Very simple. If the phase and frequency response of both channels are nearly identical, the system will image well. That’s the fundamental of “stereo”.
The source of imaging is in the recording but we can assess how the room and speaker geometry will change/influence the perception of image location and to a fair extent, though not completely, the perception of a sense of image width and envelopment. It involves simulating the propagation of sound in the room (a lot of work and some expense but not a problem these days) and quantifying the relevant psychoacoustics (trickier but doable in a less precise way).
Academic journals are likely to be the main source of information with possibly the odd text book. As you can see from the responses here there is not much interest on audiophile forums like this in what is going on in a scientific sense when it comes to sound quality. You might be better off asking in a forum for acoustic consultants. There used to be a reasonably active one on usenet but that petered out many years ago. The acoustics forum here contains one or two posters with knowledge of acoustics but their posts tend to get swamped by room acoustics noise and enthusiasm much of which is unreliable. Might be worth a post there if you have an interest in pointers towards the science side of things.
it is not that simple, phase changes with frequency and dispersion patterns, then comes the room and setup.
impulse or step response measurement will reveal some aspects of clarity.
THD and box resonance measurements are also useful.
there are other graphs that can be made that show what sort of lat and vert frequency behaviour the speakers have which will indicate some in-room behaviour but are hard to interpret (they’re space-dependent).
honestly a lot depends on what you want and what space you have. do you want 360’ stadium sound? or laser pinpoint surgical precision? there are graphs that will indicate what gear will tend towards.
No
Unfortunately it’s not anywhere as simple. Phase inter-relationships between drivers, accuracy of high frequency extension all contribute to resolution. And that’s the easy part. Enginerds have been desperately try to equate sound quality and resolution to a small set of variables, but so far the only measurement I’ve seen that gives the best hint, in addition to the ubiquitous frequency response graphs, are waterfall plots which indicate driver ringing which causes out of phase signals that interfere with a given driver’s clarity.
And then of course, room interactions can crapify any good loudspeaker’s performance.