Been doing a lot of reading the past few weeks, tossing a lot of ideas around in my head. A few basic ones clash. Here's one in particular...
It seems that "general consensus", whatever the heck that is, believes the optimum viewing angle for 2.40:1 scope films is somewhere around 53 degrees based off of THX etc. viewing height and working back to the width. Lots of threads, lots of discussion.
I'm a fan of AT screens with matching center, horizontal stretch anamorphic, and usually curved screen, so let's go from there. Pretty standard L/R speaker placements are at +/- 30 degrees. Guess where I'm going?
My problem comes from trying to reconcile keeping the optimum screen size and geometry for video (or, perhaps we can just say "as large as possible within reason") and trying to avoid things that will cause audio quality issues. Like, say, having a hard screen edge with masking motor and mechanism right up against a speaker causing acoustic diffraction and reflection issues.
Possibilities as I see them...
- Mount all speakers in a baffle flush with screen so no diffraction issues. Puts the center right up against the material. Or offset the center rearwards with delay on the others.
- Mount all speakers substantially behind the screen. Still have a hard screen edge/mechanism, now just a foot or a few in front of the speaker... now even worse for people sitting on the ends of seating rows.
- Pull all speakers substantially in front of the screen and not use a matching center. Bleh. And also narrows the potential seating area width.
- Put L/R substantially in front of the screen and center offset behind with lots of delay. Bleh for delay and spl adjustments much less good tonality matching as power response, direct/indirect ratio, driver/driver integration, lobing etc will be vastly different if there is significant path differences.
- Not use motorized masking at all so that the profile of screen frame is as unobtrusive as possible. ?? Or just invent some acoustically transparent frame and masking system?!?
Now consider this issue if one was also investigating dipole mains, where you really don't want something right beside the speaker. Very few "good" options come to mind. So few that I can't think of any. The best I can do is having screen edge aligned with baffle edge and having as small a frame profile as is possible. Masking would have to be ingenious. I think I can tackle the ingenious part. Now if the speaker baffle is curved on a radius equal to listening distance, you can only match screen and baffle edge for some of the speaker, not all. Presumable HF as that's where diffraction/reflection artifacting will be most notable.
Or, one could simple narrow the "optimum" speaker separation angle, though to have any improvement geometry-wise you'd need to further inside the frame than you would otherwise be outside the frame. So narrower than 53-7 deg, or <= 45 degrees. Probably <40 deg to be any significant improvement. Getting pretty narrow. Not an option I'd likely consider.
Or, you could widen the separation angle to say 65-70 degrees. To be honest I've never experimented with such a wide separation, though I occasionally see pics with at least this much, sometimes what looks like as much as 90 deg separation. Any thoughts on how detrimental this is to imaging, stability, etc.?
Anyone else given much thought to this issue? Obviously a bit more critical when dipoles are in the mix, but still a source of audio artifact with monopoles.