https://www.audiosciencereview.com/forum/index.php?threads/jbl-4319-studio-monitor-review.12986/

The test is a bit flawed because the tweeter was dialed up a bit high. The 4319 is a Control Monitor, not a studio monitor, so it wasn't loved by the reviewer. That said, what's impressive is the low distortion of the Jerry Moro designed drivers. 12" cloth accordion x differential drive Nd magnet. Other than the 4312E which has a TCR version of the same woofer, I think the next level up for a cloth accordion woofer would be the Everest DD67000.