Well, that's unfortunate! Lots of speaker companies claim to have a focus on coherent imaging, but nobody has any idea how to measure it? Do phase alignment/time alignment correlate?
Showing 5 responses by redwoodaudio
Above... That was a helpful addition to the thread. Thanks!
Otherwise, how are these multi-driver speakers solving this problem? If there's engineering involved there's got to be some math or measurements of some kind.
Do any speakers truly image as coherently as single drivers? If so, there must be a theory.
Time and Phase....read what JA has to say about Vandersteen “imaging champs”....
Thanks for the helpful reply. I just read JA's review of the Vandersteen Quatro Wood. His measurements are interesting. https://www.stereophile.com/content/vandersteen-quatro-wood-ct-loudspeaker-m5-hpa-monoblock-power-amplifier-loudspeaker
"Fig.5 shows the Vandersteen Quatro Wood CT's horizontal radiation pattern, normalized to the tweeter-axis response and plotted up to 45° to the speaker's sides rather than the usual 90°... The contour lines in this graph are impressively even, implying stable stereo imaging."
"Like its predecessors, Vandersteen's Quatro Wood CT offers a true time-coincident output, due to the stepped-back sub-baffles for the upper-frequency drivers, the first-order crossover slopes, and the fact that all its drive-units are connected in positive acoustic polarity. Fig.9 shows the speaker's step response on the tweeter axis. The initial arrival is an almost textbook right-triangle shape, though the tweeter's output arrives slightly before that of the midrange unit. This confirms that the optimal axis will be 5° below the tweeter axis. Finally, the Quatro Wood CT's cumulative spectral-decay plot (fig.10) is impressively clean."