Q. on shootout between time/phase coherent speaker

If 1st Order xovers are easy to drive why are Thiel and Vandersteen not easy to drive. They are both fairly inefficient with dips in impedance down to 4ohms or less - not the defintion of easy to drive. I'm no engineer, so I don't know anything about the design parameters - theoretical or implemented, both these two manafactuers make good speakers, but easy to drive is not one of their attributes. GMA, may be a different thing altogether, but I'm not familar with them.

My Reference 3A Dulcet mini-monitors are time and phase aligned. The only cross-over in them is one capacitor. They are very efficient and my 70W VAC monoblocks drive them to very realistic volumes.

http://iar-80.com/page65.html

Amp/speaker matching is very critical in achieving good sound. There are a lot of threads on time and phase in speaker alignment. Do a search for more info.

Check out Earthworks Sigma 6.2's... unreal... or should I say REAL!

My GMA Callisto's are easy to drive, very tricky to set up, adjusting toe in by even a fraction of an inch yeilds a very different sound...pointed straight ahead they sound broken. They have a quite small sweet spot, at least compared to my previous non time/phase coherent Totem Arros, those sounded fine pretty much from any angle. and they diffinately interact with my room quite a lot...again compared to my previous speakers. They are tricky enough to set up and interact with the room to the degree that I would almost be learly of auditioning them in a dealers room unless i was very sure they set them up very carefully and calibrated them to my listening hight, otherwise you're not hearing them to their consderable capabilities.

Hi Pubul57,

I don't know the answer to your question on why Thiels and Vandy's are not so easy to drive but you are right about that. OTOH, they're not extremely difficult loads either, but the point I wanted to make is that 1st order crossovers are an attribute that makes speakers easier to drive, not vice-versa. Thiel & Vandy obviously have other factors at work. I suspect that their crossovers are not nearly as simple as 1st order networks can be. Roy at GMA makes extremely simple crossovers because he fixes impedance and freq. response issues with the cabinet, the way it should be done, not by adding artificial fixes in the xover.

The crossover of the Callisto, for example, is one cap on the tweet and one inductor on the woofer! That's it. Then there is a simple Zobel network on each driver but I don't believe that's part of the crossover per se.