I'd go with JBL pro speakers simply because I can find measurements of them.
I see the JBL 8340a recommended as surrounds for higher end HTs quite a lot, which is curious because it seems to have some very real off axis misbehavior and, owing to its 10 inch driver, a narrow horizontal dispersion pattern. Neither of these are desirable characteristics in a surround speaker.
That said, I'm a big fan of many other JBL pro speakers and I commend them for publishing the data on it. I've never seen any anechoic or even gated measurements of JTR speakers.
Last edited by SyntheticShrimp; 06-27-2014 at 06:06 PM.