Time coherence - how important and what speakers?

Roy, once again thank you for sharing your expertise. Am I correct in assuming that speakers well executed from the get go can still benefit from all these "tricks" if the tricks are well executed as well? I'm sure I'm not alone in looking forward to your web site. Good luck!

If you mean digital "tricks", I think the best answer is that the value and limitations of any digital manipulations could be more easily ascertained if they were not trying to correct for things they should not be- like cone breakup, cabinet reflections, gross phase shifts, interior resonances- non-linearities which should not have been in the speaker design in the first place.

If you mean "servo control" of the subwoofer, I have not seen that applied yet to anything close to an already linear design (a well-behaved subwoofer driver and rigid cabinet). I also have never seen anywhere close to the best accelerometers being employed... so expensive! Again, we really can't hear all the benefits and the ultimate limits of servo technology.

Maybe someone who designs servo subs for a living can come forward and explain more on that subject. Anyone out there up to that?

Best,
Roy

Pardon my ignorance, but can one mainatin correct time and phase with 12 and 24 db octave slopes? Many seem to say the only way to do this is with 6db slopes. Are active cross-overs different in this regard? Can active cross-overs be time and phase accurate?

No. Yes. No. They could be with appropriate digital time delays (delays that are different for each frequency) built in. Those are available as studio-oriented x-overs with built-in adc/dac's.

Roy

Roy, your a prince. Thank you.