Thinking of upgrading speakers from ProAc 3.8 I have enjoyed in my system for 23 years.

+1 @jjss49 

and My Response 3.5 's aren't going anywhere either until my youngest takes them ~ he has already laid claim to them

Would not mind adding the K8's to the collection and a pair of ATC SCM50's

You will LOVE D48R .. They are everything your 3.8’s are and more!

I like my D40R a lot. The bass can overwhelm in a 18x18 room but it’s easy to tune it by sealing off part of the down firing port. The ribbon tweeters sound gorgeous and are better integrated than those in my previous Piega C40. These are very musically engaging speakers.

The PS Audio speakers are getting excellent reviews and I believe they have a 30 day in home trial period.  They use a high-quality ribbon type tweeter as well.  They also recently had a sale on them that may/may not still be going on.

if you like the British sound you should also look at the monitor audio platinum, G2 will be a good price because they're discontinued now and G3 are better but not by that much.

Thanks samgar2

The listing for the Proac K8 is on USAudiomart under Proac.

Thanks all for your replies so far.

I am leaning towards D48R. I will look for an opportunity to listen to SarafinG2.

I am in no hurry, 3.8’s are sounding good today.

Thanks @fastfreight. I think K8 would be too big for my room. I can't find that listing though.

I have a pair of 3.8’s that I like a lot. 
I have heard the TAD ME1’s several times at

Axpona and have thought they would be a worthy upgrade with a nice sub.

I encourage you to listen to as many speakers as you can. Technology in materials, electronics and usage of computer aided design continues to evolve and I think results in excellent speakers at many price ranges.

• If you like your current speaker, find out if you want to stay with ProAc - they make excellent speakers.
• My experience with Sonus faber has been excellent- I haven't spent much time with the Serafino G2 but I find their sound appealing and currently have Olympica Nova Vs which I'm love
• I'd encourage you to hear Devore speakers if you can

Good luck and enjoy your journey!

-1 on Sonus Faber, company has the worst customer service imaginable and their distributor here in the US is worse... will never get my $ again. Having said that I'm using Audio Note, AN-e these days. May not be as sexy (subjective) but they are spectacular in my all tube setup. Just my opinion 

You won't go wrong with either speakers. From some of the reviews I read the D-48R's are more euphonic whereas the K series is more detailed and neutral. I think it does come down to personal preference. Personally a big fan of the D-48R when I heard it but had to "settle" for the D-30R. due to room size. No regrets however. I think both speakers offer a lot for the money.

Hello @jsbail Three is a nice looking pair of K8's on USA.  I would by them if I was speaker shopping!

I have never heard the Pearls, but currently have Proac K8’s which are one of the best sounding speakers I have owned over the past 30 years. They just do everything right and all types of music sound superb. They have the ribbon tweeters which to me are one the best ribbons out there. I am thinking of up-grading to the K10. Sonus Faber was much better years ago. Now it seems like every 6 months they come out with a new speaker- “like flavor of the month”. Go get yourself a set of K6’s!

The Pearls are out of my price range. Also, never heard them. There is a pair of k-6 on another site for 17,500 which is a stretch for my budget. I will look for a dealer with Sarafinos for demo and give them a listen. I know the ProAcs are great with my 160 watt Accuphase integrated but not sure of the Sonus Faber. 

+1 for Joseph Audio Pearls if within range. Used maybe???

I owned ProAc 1.5 and now own Joseph Audio Perspectives.  The Perspectives are much better in everything.  But they should be at about 3x the cost.  
 

I love and own the ProAc D48R. I am simply stunned every time I listen to them. I have never heard the 3.8, so I cannot compare the two. But if you are looking for a dynamic speaker with vocals to die for, then these should be auditioned. I have not hear the K6, but guess that since they are in the higher end range compared to my D48R, they should be even better.

Not sure what your budget is, but these JA Pearls could be end-game speakers and exhibit many of the same qualities as ProAc…

https://www.usaudiomart.com/details/650017479-joseph-audio-pearl-3-speakers/
 

Best of luck.

The Sonas Faber are absolutely gorgeous and get my vote. They have a "wow" factor far beyond the 'square box' Proac. Sound wise both speakers have tweeter/midrange/ midbass drivers and I'm sure both sound very good. However, the Sonas Faber are world class in every respect. If you can, go see them and hear them. Stunning!!

To echo what others have said the newer Proac models with ribbon tweeter retain all of the qualities you like in your 3.8 models and sound better with improved imaging and transparency.

I have the Proac D-40r, and have owned them since I purchased from the local dealer as demo speakers. I traded in the Proac 2.5 which sounded great, but were less efficient and more veiled (which I didn't realize until I tried the new speakers.

There have been no issues with any of the drivers, ribbon or conventional.

During my time in this hoppy/obsession I have owned a lot of different speakers, but I have owned more Proac speakers than any other brand.

I haven't heard the D-48r or the K-6 so I can't help you with that question.

My system is posted if you want to look. 

Jim Perry

I wonder what their future will be. Stuart Tyler was brilliant at designing as well as voicing speakers.

For people familiar with D48R and 3.8, is it worth the upgrade , or do I need to go to K6 for it to be worth it. 

proacs remain among the very finest dynamic speakers out there, imo

they magically balance the contrary notions of see-through clarity and musicality, with an open, vivid yet still warm and human presentation - they have always sounded just right to me (which is why i still have 4 pair in house 😂)

the ribbon tweets are easily replaced if one does something stupid and damages one

spendors, harbeths, vandys, buchardts, audio notes, spatials, focals, klipsches, kefs, totems, decwares, shun mooks, grahams, sonus fabers, dynaudios, have all come and gone over the years, but the proacs have stayed in the fold

The new ProAcs are very good and retain the warm, smooth and natural sound of older models.  They are very good at integrating the ribbon tweeter with the other drivers, something that cannot be said of most speakers employing ribbon tweeters.  I don’t know about durability, but, it should not be hard to replace a tweeter if it did blow.  These days, that kind of failure is not that common unless the speakers are pushed really hard.