Really need some help finding a full range speaker


I've thus far been on the sidelines here, but I must say I've been very impressed with the knowledge many of you bring to this forum . I'm hoping to tap that knowledge, if I may, and get some help finding a new pair of speakers.

I currently have a pair of Paradigm 75f's and I've been very happy with them. To me they sound neutral, fairly accurate and exciting to listen to. But with just a pair of 5.5" drivers providing bass, they are lacking seriously at the low end.

I"m driving my Paradigms with a CJ LP70S which puts out 70 watts per channel. It has no trouble driving the 75fs but I'm inclined to buy a more efficient speaker this time around. I"m also very interested in maintaining or even improving on the accuracy and neutrality I"ve been enjoying with the Paradigms.

I'm searching in the used market and looking for a pretty significant upgrade. I'm very open to vintage options and am searching in a fairly wide price range from $1500ish (used) up to around $5k. I'm concerned about not having the opportunity to demo the speaker before I buy it, but am highly motivated by the cost to value ratio available with used speakers.

One final concern is size and aesthetics. My wife is simply not going to tolerate a tower speaker bigger than she is (or I am for that matter) and more flamboyant designs are not welcome in the listening room that doubles as my living room. I'm hoping to find a fairly straightforward looking speaker that's large enough to accommodate bigger drivers but doesn't completely overwhelm the room with their size.
thebrokenrecord
LSA-20 Statements are available here new discounted to $4500/pr (normally $7k) and, very importantly, offer a 30-day, in-home trial. They’re only 39.5” tall and 9.5” wide but will go down to 25Hz and will likely be a considerable improvement over your Paradigms in virtually every area. These may be a very good fit for you for many reasons.  They’re sold direct so offer very good value for what you’re getting. 

There are a couple pairs of Nola KOs available here now that love tubes and will bring a very impressive and “live” feel to music with their dipole midrange/tweeter arrays, and they’re only 4’ tall and not very wide so not too imposing. Used Joseph Audio Perspectives are a fairly easy load for an amp and will also be a significant sonic upgrade in every way. They are very attractive with a small footprint (i.e. very wife friendly) if you can stretch to $6k, and you also have the option to upgrade to the new Graphene drivers if you want even more down the road. Lastly, there’s a pair of Usher CP-8571s with Diamond tweeters available on US Audio Mart for $4500. They’re not very tall or wide and they’re downright gorgeous end-game-type speakers, but they’re quite deep and weigh 250 lbs if you can swallow that. Hope this helps, and best of luck in your search.
+1 for tomic601's Vandersteen suggestion. If your lucky enough to be able to audition most any Vandersteen model along side your Paradigm's you'll experience, as my family and I did, within the very first minutes what time and phase design brings to a speaker presentation. To quote my wife, "...wow, it's not even close."

Close your eyes and pick out the individual drivers of each pair. If setup properly you'll have difficulty doing so with the Vandersteen's.

In my limited experience full range low frequency has more to do with the ability to control individually powered woofers by equalization, gain, and proper room placement.  

All the best in your search.
@robertbrook I have the same Paradigms that you have, the 75fs.  It's interesting that you feel you need more bass?  I absolutely loved the bass on the paradigms.  Very fast accurate and punchy.  They don't go super low and they don't make your chest vibrate but I was very pleased with the bass. There were other aspects to them that I didn't love but I do think they are really nice speakers, especially if you like a very clean and exciting sound.  I would agree with the folks that say add a couple subs if you want bigger bass.  Also, if you haven't already, look into getting some bass traps for your room.  I was shocked at how they not only improved the clarity of the bass but the amount as well.  Plus it's a lot cheaper than buying new speakers  ;)    Good luck!
I will add a third recommendation to look at the Audiokinesis Swarm subs; with them you will get good bass to 20Hz.
The speaker you need to do 60Hz or so and up is then a fairly easy prospect as it does not need to be large!
+1 ianrodger.
ZU:  I purchased ZU Omen Mk II,  3 months ago. I’m waiting for new Soul Supremes to arrive now at end of month. I do use a subwoofer They have an excellent trade in program. Check out the details on their website.  I got full purchase price back for an upgrade to the Supremes. Their speakers are fantastic or I wouldn’t be trading up. 
Bent