Sloped baffle

Mofimadness answered correctly
About time alignment.As far as phasing... it is simply having your individual drivers operating
In unison at all frequencies... As you change crossover points and slopes, phasing changes between drivers.... Correct time and phase alignment is what seperates many ok speakers
From world class speakers... These factors are why so many audiophiles like sigle drivers or point source.... I hope this helps, Tim

Bifwynne,
your entire post is a LOADED question! :-)
we have discussed this way back in 2002. Here is the link to that thread (many very good & informative & technical posts by Roy Johnson of Green Mtn Audio speakers):
http://forum.audiogon.com/cgi-bin/fr.pl?cspkr&1032037028

And here is a thread that Gmood1 started on Time & Phase as related to speaker operation:
http://forum.audiogon.com/cgi-bin/fr.pl?cspkr&1060123575

And, finally, member Rbischoff (who started the 1st thread, above, that I provided the link) started another thread on First Order Cross-overs: Pros & Cons:
http://forum.audiogon.com/cgi-bin/fr.pl?cspkr&1113252618

There is a great deal of really good info on this subject of phase & time coherency. Happy reading.... ;-)

Bombaywalla, ... that;s for the links. I started reading into the threads. This is very complicated stuff. And I thought getting my arms around amp and speaker compatibility was tough. Speaker design is a beast. I will return to these threads over the weekend.

In the end, as it seems to be the case with end end electronic gear, we're talking about design compromises. No perfect solutions ... just trade-offs that hopefully result in a product that sounds good.

Thanks

I think so, but only if in combination with 1st order crossovers as used by Thiel and Vandersteen, revealing a coherent time-aligned step response.

Bifwynne,
welcome.
I figured that these links would NOT be wasted on you. :-)
indeed, speaker design is a complicated affair. Fully understanding what's going on takes skill, knowledge & experience as speaker design involves the mechanical aspect of actually building the speaker but also understanding what the electrical effect of the x-over is to the mechanical aspect. It's an inter-disciplinary expertise.

In those links, there's a lot of chatter by members who don't know what they are talking about & by those who are airing their thoughts & experiences. You can skip over that which will shorten the reading time. Pay closer attention to the speaker manuf posts. Those are revealing in info.

Well, now that you have the amp-speaker interface licked :-) it's time to go a bit downstream & understand what that electrical-to-sound transducer is all about...