I tend to have a hard time with IR’s and convolution reverbs in shaping the ENTIRE reverb signature. Especially in the tail…music is very much about inconsistency, and motion, and change, and a static, one-shot-fits-all reverb tail from a convolution impulse is by definition unchanging, fixed, and…just bleh.
On the other hand, I find IR’s capture the Early Reflections of a place the best. It’s hard for an algorithm to replicate the chaos that happens when sound waves hit each other and go crazy in a room, so they tend to sound too simple and orderly and clean.
So, I use the Early Reflections on Waves IR. Clairmont, Herbert Zipper and Belle Meade and Presidio are the ones I tend to use, but then replace the tails with an algorithmic like Valhallaroom. You could even adjust the tail length to match the impulse’s length.
Or…try baking it yourself by having two instances of IR, one running just tail and one running ER, and send the tail through a really, really, really slow chorus or flange, particularly one that does its thing in the stereo field, and once you tweak it right (i.e., so that there’s just some motion in the tail, not an actual chorusing effect) then it gives it some life.
One thing I didn’t ask was what samples you’re using in these! Most of these ideas apply for VSL or LASS, or something else which has very little room information, either in ER or tail. If you’re running, say, a Spitfire Instrument from the Decca Tree through Waves IR, you probably are doing it wrong!
And finally, don’t feel like you have to use a hall because it’s “Orchestral” music. If you’ve got a good scoring stage ambience for your instruments, but they’re just too dry, then you might try something like the Plates from the free Bricasti set of impulses. A fair number of orchestral recordings have been given a good dose of Plate Reverb to finish off a Decca or ORTF setup that was too dry, so you’d be in pretty good company!
btw, you might share a soundcloud link to something that was rejected for Reverb. That’d get more ‘specific’ tips!