Had a big listening session with 3 pairs of JR149s yesterday. The purpose of this was partly to try to determine if any of the 6 speakers was audibly out of spec.
The JRs were all used as the mid and treble of a 3 way semi-active system. This allows the speakers to perform to the best of their ability and tends to highlight the characteristics compared to using them full range.
Pair 1 and pair 2 have been recapped using Falcon Audio's kit of electroytics and pair 3 has been recapped using Monacor poly caps. Pair 3 is still being renovated and was run without the mesh cover over the drivers and without the foam sleeve.
In summary Pair 1 and 2 sounded indentical. Pair 3 sounded slightly smoother, clearer and more open. Further investigation with all combinations of the mesh and foam sleeve strongly indicated that the mesh has a negative effect on the sound. We ran out of time to see if the Monacor'd crossover sounds different to the Falcon'd ones.
We also tried a pair of LS50 Metas. The sound was noticeaby different to the 3 pairs of JRs. More hifi and less music is how I would describe the Metas.
The owner of these speakers also has 2 pairs Spendor LS3/5As. We didn't bother to listen to these as the JRs have been preferred every time we tried the comparison in the past. The LS3/5A seems to cross over to the LF less seamlessly than the JRs and the upper-mid squawk is more apparent.
Our fairly unscientific conclusion is that B110 and T21 don't audibly drift out of spec... or if they do they a drift in a similar manner.
The other conclusion (again!) is that JR149s are cracking speaker when very well integrated with an LF system.