Klipsch KLF30s vs JBL 120ti

@ahope4836 --

The JBL 120Ti’s are very good speakers (owned a pair of them some 35 years ago), much better indeed than some would give them credit for. One of the reasons for their unused potential is that of not being paired with 1) appropriate quality amps and 2) a great source (for the price they can be had, also new at the time, people may have been inclined to set them up with gear that didn’t do them justice), but once you do you’ll be surprised at the level of presentation they’re capable of.

The drivers used in the 120Ti’s are excellent and part of the reason why they sound so good, not to mention also being very revealing of what’s fed to them; those 044Ti tweeters didn’t flatter the less than ideal digital sources of their time, the 128H-1 woofers shine when paired with powerful quality amps, and the small gem of a midrange driver, the 104H, will reward attention paid to amp + source quality as well. Be sure to put the 120Ti’s on quality stands. 

So, my advice would be to optimize the performance of your JBL 120Ti’s and skip the Klipsch speakers. Depending on the source you already have, look at possible upgrading that instead (or save your money). Don’t know your vintage Pioneer amp, but I suspect - down the road - you could wring even more of the JBL’s on the amp side of things. 

I have not heard the JBLs, but owned the KLF-30 for a long time and can provide an idea of what you'll be getting with those.  I found the KLF-30 easier to listen to, especially at high volume (less bright) than other Klipsch speakers I've owned (which are many).  They are far more efficient than your JBLs, will move a lot more air and easily achieve high sound pressure levels.  They can benefit from a Crites titanium tweeter.  The KLF-30s may not image as well due to their size (I'm guessing here).  The biggest thing to look out for with the KLF-30s is the back panel coming loose.  This can be fixed pretty easily with some good wood glue, but is a known issue.  They can also benefit from internal bracing also.  They are big and will do best in a large space.  They should sound great with the types of music you enjoy and if you enjoy bass, they should bring more of that to the table with their dual 12" woofers.