[richidoo]

I don't understand the finer points of driver Q. Why higher Q is preferable to lower in an open baffle, how to decide what Qts to shoot for, etc. Are there some online references to explain in layman's terms what speaker specs are all about. I have the loudspeaker cookbook, I guess I could put in the labor to study that, but hoping for something little less intense for a quick overview.
Thanks
Rich

[Davey]

Well, I wouldn't say that higher Q is preferable to lower in an open baffle.  It all depends upon your ultimate roll-off goal and how you're going to implement it.  How much (if any) EQ will be required....whether that EQ will be passive or active....the baffle type and dimensions....etc, etc.

Since an open-baffle configuration will operate the driver in its "free-air" mode the manufacturers Qts figure will determine the ultimate roll-off of the driver...pre equalization.  Well, there is the Ripole.... 

Many DIY folks seem attracted to drivers with higher Qts (> 0.5) specifications because the rising response before cutoff can be used to achieve some "native" 6db/octave dipole correction.  (This was the concept of the Carver Amazings many years ago.)

As most folks would recommend....the Linkwitz site is a terrific info repository for much theory/application on this subject.  Here's one tidbit:

http://www.linkwitzlab.com/faq.htm#Q34

Dave.

[richidoo]

Thanks Davey, that's helpful!!   
Rich