Where to go next with the turntable

@traudio 

"More bass warmth" is a speaker/room/amplitude issue. All the best cartridges are very close in amplitude response striving for a flat curve from 20 Hz to 20 kHz. They are all within a dB of each other. 

As far as turntables go the real issues are less noise, both internal and environmental, better interface with the record and accurate speed control. The Thorens 1600 is the next step up from Rega. It is a fabulous turntable for the money adding a good suspension for environmental isolation. Form there you are getting into the Sota Sapphire with a Schroder CB or Kuzma 4 point 9. This adds a magnetic thrust bearing for less rumble and much longer bearing life. Adding Vacuum clamping and Sota's excellent mat gives you the best record interface. Moving up to the Sota line to the Cosmos gives you incredible speed accuracy, a 1" thick aluminum chassis, a constrained layer tonearm board, and vacuum clamping. Then you are off to megabuck tables like the Dohmann Helix, Basis Inspiration, Avid Acutus and SME 30/2 and 12.   

@traudio , 

You are entirely correct about the LP 12 being a PITA. The suspension is a terrible design. Please do not let that sour you on suspended turntables. They will have superior bass due to the absence of environmental rumble. Your subs will like it also. A system Like yours deserves at least a Sota Sapphire. You can set a bomb off in front of a Sapphire and nothing will happen, even if it is sitting on a folding table! David Fletcher pioneered the design now used by Basis, SME and Avid. The chassis is hanging from the springs instead of sitting on them, a much more stable approach. I am extremely familiar with 3.7s. I have set up a bunch of them. Good for you using subwoofers. If you are looking for more punch and more forward bass. The Clearaudio Charisma will do it. You can also work with your subwoofers. Chances are you are using the low pass filters in the subs?? If so that is an AWFUL thing to do, much worse than not cleaning your records. The 3.7s benefit from removing at least 80 Hz and under from them. The problem of matching subwoofer is impossible to do well by analog means. It is impossible to get the timing and phase perfect by ear. I should know. I tried doing that for 15 years starting in 1979. You need digital bass management. With it you can make your bass sound however YOU want. The best way to do it is with a digital preamp like the MiniDSP SHD or Studio with outboard DACs (Benchmark uses that approach), The Anthem STR, the Trinnov Amethyst and my favorite the DEQX Pre 4. The Pre 4 will not be available for about 6 months. It's big brother the Pre 8 is being released just now. The only difference is the Pre 8 has a full 4 way crossover in it. You could tri amp the 3.7s and run your subs. It is about 3 K more dear. You subs you would cross at 80 hz 8th order (48dB/oct). You could actually push it to 100 Hz without getting the subs into the midrange. You will get another 6 dB of headroom, a cleaner midrange and the improvement in bass WILL blow your mind.

Having said all this, you will still benefit from an improved record playing device. If it were me with your system I would get a Sota Sapphire and put a Kuzma 4 Point 9 on it. I would use the Clearaudio Charisma or if you should go the route of the digital preamp the Soundsmith Voice. 

@traudio ,

Which is not a whole lot. The lowest note on a 4 string bass guitar is 40 Hz. 

Play a 20 or 30 Hz test tone, turn the volume up and put your hand on the panel. You will feel it vibrating. That vibrating distorts everything else. If you only listen to string quartets at low volumes it does not matter. If you use a turntable even just the records themselves generate rumble exacerbating the problem. A flat response does not necessarily mean a detailed performance. A system can do a short sine sweep beautifully and sound terrible. You are familiar with MiniDSP. The SHD is $1500 with the UMIK 2 and it will do everything you need including a digital two way subwoofer crossover which will allow you to take the crossover point up, cleaning up the Maggies. MiniDSP also makes a stand along crossover.

If the Sota Sapphire is too big a bite I encourage you to look at the Thorens TD 1600.