Proac Response D40R or D48R

Ribbon tweeters can be more narrow / more focused / more "beamy" than dome tweeters. I witnessed this when I demoed a pair of ascend acoustics sierra towers with a high end RAAL ribbon tweeter. No the speaker for me, mostly for other reasons.

I really do enjoy the ProAc sound and while the D20s I demoed got loose on the lower frequencies, my ProAc studio 148s are the speaker for me (budget, soundstage, tone, size and frequency response). Try some Soundocity SEV9 outriggers with your 140s. I use them and love them. You can use them if you upgrade also. 

I own the Proac D-30R's and had a chance to briefly audition the D-48R.
What impressed me most with the D-48R was its effortless sound. It just
sounded so natural and musical that you sort forgot about everything else. The ribbon tweeter is wonderful by the way. Not bright or edgy, just very smooth and extended.

cmach, how big is your room?   

cmach, is the D-48R a significant step up from the D-30R?  I am considering the D-30R.

A new version is on the way the D30S that use the same revised new driver of the D48.
 The D48 must be significant step up from D30 due the extra driver ; deeper bass and more clarity and control in the mid.