Upgrading Maggie MGIIIa's to 3.7i - worth it?


I'm suffering from upgrade fever but nothing is easy.  I'm quite addicted to the Maggie sound so considering an upgrade from my ancient IIIa's to 3.7i's.  But of course there's a catch - the old MGIIIa's got a full factory rebuild a few years ago. This entailed new membranes/wires, tweeters and covers.  At the time Magnapan said they'd be "much better than new."  And so it was.  They sound great!

And so, the question:  Is the upgrade to 3.7I's worthwhile?  To be worth it the improvement would have to be substantial, not just incrementally better at this or that.  What might I expect? FWIW, they're being driven by a recapped ML No. 322 which drives them very well indeed.  Any thoughts?  Thanks,
raueda1
The IIIa’s have the largest bass surface area and lowest bass of any of the Magnepan 3 series.

I use them in my home theater setup and could not be more pleased.

I suggest you keep them since they have been rebuilt and are essentially new.

I've listened to many Magnepan models over the years but never heard the model IIIs. As I understand it, one of their best features is the true ribbon treble section and one of their worst is being about 25 years old. But I believe you having them recently fully rebuilt, including the ribbon tweeter, probably extended their lifespan for another 25 years.
    I recently bought a pre-owned pair of 3.7i, upgrading from a pair of 2.7QR that were also about 25 years old. My decision was much easier, though, because the 2.7QRs have the quasi-ribbon treble section and I wasn't considering having them rebuilt. I've powered both with a pair of D-Sonic M3-600-M mono-block class D amps rated at 1,200 watts at 4 ohms with very good results.
    I noticed a significant improvement in the treble performance and detail levels with the 3.7is that you're probably already experiencing with the IIIs. I believe all 3 models, the 2.7, 3.7i and III, have similarly sized quasi-ribbon midrange and bass sections that are very good but only have bass extension down to about 35 Hz and lack the capacity of powerful bass impact and dynamics.
     However, I also understand the symptoms of upgrade fever very well.  My suggestion is that you keep your IIIs and satisfy your upgrade urgings by buying a high quality bass system like the Audio Kinesis Swarm complete bass kit for about $3K reviewed here:
https://www.theabsolutesound.com/articles/audiokinesis-swarm-subwoofer-system/

     I've been using the very similar and equally priced Audio Kinesis Debra complete bass kit for over 4 years now and it's the best upgrade I've ever made to my system. I can confirm that the above review gives a very accurate description of what bass performance levels to expect.  
     These bass systems are based on the scientifically proven effectiveness of the 4-sub distributed bass array (DBA) concept developed by acoustic expert Dr. Earl Geddes.  
     Prepare to be amazed how extremely well the 4-sub DBA system will work with your Magnepan IIIs.   You would continue to operate your IIIs full-range and either the AK Swarm or Debra complete 4-sub DBA system will extend your system's bass down to 20 Hz +/- 3dB and the bass will be powerful, dynamic, detailed, smooth, fast and natural in virtually any room and integrate seamlessly with virtually any pair of main speakers. So, , it would likely be the last sub system you'll ever need to buy, even if you move or choose to use different main speakers.

Tim
Much better speaker upgrade asap!!
HMU if you decide to see the IIIs.
Y'know, it's a funny thing.  I've never felt that I lacked for bass.  The speakers are in pretty large space.  The room is about 16x30 ft with tube traps in the corners.  One speaker is about 5 feet from the side wall while the other is roughly 20 ft from the side wall.  Both are about 3" from the rear wall.  Maybe this setup is conducive to good bass. 

In any case I'm still very much on the fence.  The 3.7i's would set me back about $6k.  I suspect that the 3.7i's would be an improvement, though I doubt it would dramatic.  As it is the IIIa's sound damn good and they're factory renewed, hence better now than they were to begin with.  Moreover, there are certainly other upgrades that might have a bigger impact, though at the moment I'm not sure what they'd be.  Maybe better streamer?
So, I'm going to try to find a dealer someplace to give the 3.7i's a listen.  This will doubtless be a long and drawn out process.  Thanks for the remarks.
Hello raueda1,

     I agree that the bass from the IIIs, 2.7QRs and 3.7is are sufficiently good that many don't feel the need for subs or a bass system.  Understandably, however, I believe the vast majority just don't know what they don't know because they've never experienced near state of the art bass performance in their room and system.  BTW, I include myself as a former member of this group.  
     Until about 4 years ago, I had no idea either about how extremely well the 4-sub distributed bass array (DBA) system concept actually performs in virtually any room and with any pair of main speakers.  I could describe again in detail the near state of the art bass qualities that a 4-sub DBA system consistently and reliably provides in my room and system but likely convince very few.  But I also know it's true that it would only take a relatively brief audition of one in person to convince virtually anyone.  
     I'd like everyone to know that I have no financial or any other association with Audio Kinesis or the 4-sub DBA concept.  I'm just a very satisfied customer and user and my intent is just to spread the word on its extraordinary effectiveness.  I don't consider myself a bass-head, but rather an enthusiast of high quality and natural bass reproduction on music and HT audio.  
     Even though I doubt it's considered an accepted standard measurement of bass system satisfaction, I can say with certainty that the AK Debra 4-sub DBA system puts a smile on my face on a daily basis whether using it for music or HT.


Tim 
I agree that the bass from the IIIs, 2.7QRs and 3.7is are sufficiently good that many don't feel the need for subs or a bass system. Understandably, however, I believe the vast majority just don't know what they don't know because they've never experienced near state of the art bass performance in their room and system. BTW, I include myself as a former member of this group.
I'm absolutely sure this is true!  But to be honest, I just don't want jump  into that particular rabbit hole (seems like all this stuff is one rabbit hole or another).  First, in this case I'm content not knowing what I don't know, leaving me in an ignorant bliss.  Second, I just don't really have the space for such an array and it would take massive rearrangement.  Finally, my upgrade fever might take a turn in other upgrade directions.  I've mentally budgeted for the $$$ for the  3.7i's but there are other possibilities too.  Better speakers for the "casual" living room system ([i]lots[/i] of room for improvement here!)?  Upgrade media streamer the big system?  Other?  Thanks for the comments though, even more grist for the mill. The journey is the destination sometimes.....