Richidoo ... (or Danny) ... what would you think about supplementing the low end of one of those Feastrex drivers with something like the OB7 low end or the new high efficiency 15" dipole low end unit Danny is working on?
I have kind of been there and done that with the full range drivers. I even have some setting on my desk as computer speakers right now. Some are really good. I have also designed crossovers for speakers just like what you just mentioned.
I did crossover design work on these:
http://www.azzolinaaudio.com/index.htmlAdding an additional low frequency driver is not hard. Making a two way design out of it works great.
I would imagine some of our direct servo subs would be ideal.
Might also supplement the very high end with one of Danny's planars or a great tweeter?
This actually doesn't work very well. In fact adding any super tweeter to a full range driver winds up cancelling the on axis response in one area while adding a lot of gain in another area. It makes a real mess out of the response all across the top end. Even if you find a spot with a minimal amount of cancellation, move up or down a few inches and you'll have the massive cancellation again.
Another thing that I have noticed is that as good as many of these drivers are, they are still not as good as a good tweeter from about 2 or 3kHz and up. The smaller diameter tweeter will always have a better (wider and more even) off axis response as well. So if you are going to use a tweeter then you might as well design the crossover to take advantage of the strengths of the tweeter and cross it in a lower range.
However, I have noticed that one can add a rear ambience type tweeter facing to the rear or facing to the rear and/or upward will add a little upper end air and space without directly cancelling or disrupting the on axis response.
Another thing to remember is that the heart of the midrange (or vocal range) is in the 300 to 500Hz range.
