Are older designs like the Celestion SL6, SL12, SL600 or SL700 that were cutting edge 15 years ago still comparable to 21st century loudspeakers like the Revel bookshelfs and other top quality bookshelf loudspeakers available now? Or are the designs, materials and drivers last generation and it's time to move on?
I ask because some of these high end Celestions show up for sale used and in good condition for reasonable prices. Out of the better Celestions I have only heard the SL6000 system that I believe uses SL600's and a pair of uniquely designed 12" woofers. I was impressed when I heard them 15 years ago but I cannot mentally compare that sound with what I hear from modern speakers.