Re: Need more head room, long, narrow room
So is less than 6dB minimal or greatly?
Less than is minimal, more than is a great or large variance.
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.
Exactly what I have said numerous times now. If you use the listener being OUTSIDE that pattern to make the volume less closer to the speakers, as was suggested previously in this thread, you have introduced a frequency dependent variation into the sound.
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.
At this point, you are just supporting my very first post in this whole thread. I was not the one who brought uniformity of level into the discussion. I was the one who stated I would not accept uniformity of level at the expense of spectral balance. Yes, a SOS rig is a compromise. A flat front speaker is sending over half of the energy into reflections. If I can tilt the box and put that energy directly on the listener, without moving the farthest listening positions outside of the direct pattern, why wouldn't I?. Yes, I may give up a little level in the back due to reducing the reflections, but I prefer clear over loud anyway.
The original post was about a 30 m audience depth. Obviously, nothing you are going to do with the stand is going to smooth out the level difference at that range. That was never my point. My point was, and is, and always will be, that you can improve the spectral coverage at the front, WITHOUT changing the coverage in the back of the room.
I have been doing a bluegrass show in a room that was notorious for bad sound. It is a converted milk barn with cathedral ceilings. Every time a band tried to play there, they had tremendous problems with the reflections causing both a lack of clarity and feedback problems. I went in with my own system, ignoring their flat front hung JF250's, and started doing the shows with a pair of K10's at about 9 feet with about 10 degrees of down tilt and significant toe in. In that position, a person sitting in the center of the first row is still clearly hearing the HF, AND not only is a person sitting in the back row still hearing the HF, BUT a person on the balcony in the back of the room is still hearing more of the HF directly from the horn than from reflections. The 90 degree conical horn can cover all three listening positions. Yes, the compromise is that I am giving up equal levels as the closest person to the speaker is about 6 feet and the farthest about 100 but with open seating people can adjust to the level they prefer. No one is likely to move around the room (except for me, I do admit to having done this) to adjust the tonal quality to their liking.
I am fighting the same problem in a club I am in regularly these days. In order to get the level at FOH, the dance floor is uncomfortably load but lacking clarity. I think the mains are mounted without enough down tilt. There is a giant hole in the HF coverage in front of the stage. The owner paid a lot fitting the entire ceiling with absorbent materials but that was really just a band aid on a less then effective install. Personally i would not be trying to cover the entire room from the stage, but would add the delay ring to help towards the back.
So, point the speakers at the people and away from the reflective surfaces. I find that adding a second dimension to the way I can arrange the boxes makes that easier.
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