I'd like to clarify what exactly is needed for proper horn 'time alignment'? Is it just a question of having as close as possible alignment of the voice coils of the various drivers vs. the listening position or more complex? Jean Hiraga on his book on loudspeaker suggests that the alignment is not necessarily linked to the voice coil, but instead to some variable plane where the image would form within the horn throat, so that it require complete experimentation rather than a fairly straightforward locating all voice coils in a plane.
I'm using a 3-ways with a 15" bass speaker not horn loaded, a 2" mid with a round horn and 2405, aligning the voice coil of the mid driver with the bass would require significantly advancing this driver vs the front of the bass box, is this the way to go? I'd be interested in any advice on this.
Carolus, if you happen to read this, I'd like to have your opinion, I know you're pretty keen on this proper alignment,