Time and Phase Coherency

[goodman]

<font color='#CCCCCC'>Time and phase coherence are made much of in some quarters, yet there are only a few manufacturers who seem to adhere to it, notably Vandersteen, Thiel and Meadowlark (Dunlavy did too when it was still in business). &nbsp;These manufacturers pull the midrange driver back slightly from the woofer, and the tweeter back slightly from the midrange, so that the sounds from all drivers ostensibly arrive at the ear at the same time. &nbsp;Is this important, and if it is, why don't more manufacturers do it? &nbsp;Also, couldn't we do somewhat the same at home by tipping our speakers back slightly?
Also, what's up with phase coherence? &nbsp;Does that have to do with wiring speakers in or out of phase?</font>

 

[Rob Babcock]

<font color='#8D38C9'>It usually isn't enough to merely tilt them back. &nbsp;A truly phase coherent speaker is electrically in phase and incorporates first order x-overs.

Not everyone builds phase &amp; time coherent speakers, for seval reasons. &nbsp;One, going with first order X-overs will often mean you lose dynamic ability and power handling (eg the tweeter isn't filtered steeply meaning it will be playing more of the mids, too). &nbsp;Secondly, there's not a lot of evidence that phase diffs are audible. &nbsp;If you don't think they are then why go to the trouble of designing them that way?

BTW, VMPS speakers are also time coherent and aren't terribly expensive, and they have a very good reputation.</font>