I'm building a pair of horn speakers and noticed many types. Horns are categorized in degrees of dispersion ie 90/40,60/40,40/20..90/40 being wide and 40/20 considered narrow. I will be sitting about 20 feet from the horns with only the left channel near a side wall. The mid range horn will be large,about 30 to 39 wide and about 25 inches high. I want something different as my current system is very open. I have noticed a TAD horn TH4001 is wide but not high and is well liked. What can I expect with a large narrow dispersion horn,as opposed to a wide dispersion type horn?