I agree with Derek, though the adjectives I'd use are "dark" and "veiled". I was never able to warm up to any of the PL-series woofers. In every case I've heard, the "classic line" equivalent (e.g. M10 for PL11, M18 for PL18) was markedly preferred over the PL woofer. The PL18's seem to have the same problems to my ears as the ScanSpeak 8545, another widely respected driver that I've never been able to stand.Derek said:the pl's just sound fat.
sloppy and fat
Though I've not heard the CA18, I'm sure it's excellent. Of the 7" Seas midwoofers I have heard, the fiberglass-coned G18 is my clear favorite, but I've never heard the paper one.