Time coherence - how important and what speakers?


I have been reading alot about time coherence in speakers. I believe that the Vandersteens and Josephs are time coherent.

My questions are: Do think this is an important issue?
What speakers are time coherent?

Thanks.

Richard Bischoff
rbischoff
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
So why is audio staying in the dark ages with passive crossovers? Even a listen to Mackie HR624 active monitors?Shows what active croosovers are capable of. Something to do with not being able to pick your own power amp?
I will admit that passive ATC 10's with ATC $3,500 integrated may have sounded better than active 10's with built in ~$500 amps so the power amp must be very good to see the improvement. Obviously a single $3,500 could be better than 4) $125 amps and this could explain why.
Good question! Active x-overs/built-in amps are great!

Of course, the cost of those parts and the extra labor multiply into a higher retail. Existing powered-speaker companies offset some of that by using far less than the best woofer, tweeter, cabinet, wire, terminals, amplifier design and electronic parts, and via quick-assembly techniques- like push-on connectors to the drivers.

The powered monitors sound better than their competition, but this only reflects on how bad their competition is, and not on what can really be achieved with proper drivers, cabinets and passive crossovers for the same total cost, or less, including the outboard amplifier- which can be changed that day if it goes bad, as opposed to sending the powered speakers in for repair. Talk to a repair tech about the bright idea of building a VCR into a TV set. Makes them curse...

Home users would have to scrap their existing amplifier to use powered speakers- not likely.

Whose amplifier design do we put in, assuming they would even sell their "best design" to a speaker company? Rowland, Edge, Audio Note, 47Labs, Bryston, Wavelength, Manley... none are perfect. And they always get better (almost always) every year or two.

Those are the reasons which have kept us from putting in active electronics here.

Except for the compromised powered monitors out there, or cost-no-object reference speakers, we would seem to be stuck with passive crossovers.

Best,
Roy
Good points Roy, Thanks. Keeping phase coherence sounds liek a good idea but I had a couple of novice questions on phase coherence, if you have a chance to answer. I don't think they were answered above.
- Is time / phase coherence maintained through the whole recording / playback process so the speaker is the only thing messing up phase and time coherence?
- What if a driver naturally rolls off greater than 1st order. Does the crossover have to boost the driver? Is this bad?
- Would the extra power handling of the voice coils in 1st order x-over degrade performance in other ways like higher inductance, mass, and hysteresis?