>I have a pair of old Snells with rear firing tweeters...just curious why we don't see this configuration more today ? Phase issues? Placement problems? Engineering issues?
We're trying for uniform polar response which is already much broader than the midrange's dispersion with typical mid-bass driver sizes (5"+) and cross-over points (2.5KHz+) where the local directivity minima contrasts with the mid-range driver's increasing directivity to produce a harsh sound due to excess energy in the 2-4 KHz range.
If you have mid-range output headed out back as in a dipole having similar polar response at higher frequencies helps and a rear firing tweeter works well; although otherwise it's not a good idea.
We're trying for uniform polar response which is already much broader than the midrange's dispersion with typical mid-bass driver sizes (5"+) and cross-over points (2.5KHz+) where the local directivity minima contrasts with the mid-range driver's increasing directivity to produce a harsh sound due to excess energy in the 2-4 KHz range.
If you have mid-range output headed out back as in a dipole having similar polar response at higher frequencies helps and a rear firing tweeter works well; although otherwise it's not a good idea.