Re: Need more head room, long, narrow room
So is less than 6dB minimal or greatly?
I'm not aware of any pole-mountable full-range speaker systems that have effective pattern control over their entire bandpass, so at some point tradeoffs need to be made. When that occurs will depend on the specific loudspeaker. If we consider a 6dB (+/- 3dB) difference as "minimal", then as long as the listener is within the nominal pattern of the horn (which for well-designed speakers matches reality pretty well), there is minimal frequency variation over the listening area. This is especially true if one uses the 3dB down points as the reference, instead of the on-axis point. If a 6dB variation is "greatly", I'm not aware of any loudspeaker systems on the market that don't have a greatly varying frequency response.
But as I said before, speakers on sticks represent a compromise. My experience with speakers on sticks has been that while height and downtilt are useful for reducing the amount of excess energy being used to excite a reverberant space (to a small degree), it is not possible to get enough of either to make a significant difference on uniformity. YMMV, of course.
