Re: Variable sound quality, JBL PRX rig
Ok, so, apologies for unfocussed nature of this reply and the inevitable information overlap between this thread and that other one I made (same solutions, well, used advice from both, anyway, enough lurking, time for some replying to awesome helpful responses!!)
Ivan - I believe I mean polarity. The flicky switch on the back of the subs where if you press one but not the other and everything is as it should be you more than halve the volume output.....when this manifests in the tops the stereo imaging goes to hell and you lose the illusion of centre.
Took this measuring advice to heart and obtained a db meter and a pink noise generating app (although possibly neglected to do each speaker individually for some reason). Found with music 10 metres back the PA was struggling to hit 95db. Also went on a quest to obtain an RTA mic. Whilst messing around with that trying to get the driverack to acknowledge signal and do it's auto things PA put out a little over 105 db at one point (felt rather sick after that little escapade).
Post Auto leveling and EQ everything sound MUCH better. I am wondering now if a bunch of untamed low end resonant frequencies I was never game enough to notch out on the graphic were perhaps masking frequencies higher up? I lost a bit of volume, but everything sounds nicer, tighter (as one would predict).
Per - With the speakers on the wall thing, I've pulled them out as far as possible (maybe 7 cms clear now and point in slightly), I do reckon that makes a bit of a difference. Could be speaker position slowly drifting closer towards the wall was affecting the sound? (I have another theory about that now to do with the master volume being turned up during intermission and second acts being done at louder volumes and speakers Never sounding nice when they are struggling).
The reason I wanted to move the subs was because people kept telling me to line up the subs with the tops so everything is time aligned and I can work out how to compensate for subs being in front or behind the tops but clear firing off in another direction? Simply melts my mind. Tis possible that they could sound loudest and nicest under the stage With the SMAART processing (although I have secret other reason for wanting them out along the lines of powered speaker needs to be able to cool itself and massive pocket of bass on stage/backstage makes everyone on stage feel sick). Post SMAART everything sounds nicer so I could be off the hook now, if it hadn't worked, I concede, I would have had to put them back where it sounded better.
Chuck - Checked 
(well, not the cross over bit but both polarity switches are out currently, and having them both in made no noticeable difference when paired with tops).
Steve - Ugh, the Worst room! (See pictures, show and tell time :-D) The nicest I've ever heard them sound is when run like you say, no external dsp, just sub, then top. However, this is a dry hire situation and I am primarily looking for system protection (although the thought occurs to me now I could just have bought a compressor limiter, anyway). I've no doubt they are the right speakers for the job, but I will have to work with what I have for now (which will soon be four. Try 2 aside not for extra coverage but so none have to work as hard). Just curious but do you not find the PRXs to have some serious bite around 4k which is almost impossible to EQ out? (As in, when you EQ they sound dead and that middle ground is hard to find).
Steve or Tim - Can either of you confirm for me that the Flat response requires the EQ button to be pressed in? I've been puzzling over this for the last 12 months. Every time I try and logic it out using the mic/line switch for reference I draw the same conclusion.
Tim - Could volume factor into the PRXs sounding bad?
Ron - mentioned in passing but formal answer, it's a DBX driverack PA+
Scott - I've been lurking but putting off replying because it was always gonna be loooooooooong. I was hesitant to run full range because of the volumes required but if I crank 2 a side (with neither having to work as hard), I shall try that, I wonder if running full range will help negate the disconnect between sub and top?
Alright, time for pictures
