Hello kingbarbuda,
I completely agree with you that subs are hard to synchronize and really match up with Maggies. It seems like we've both been disappointed in the past trying to integrate them seamlessly.
You threw in the towel with your 1.7is, professional audio reviewer Steve Guttenberg has given up trying with his 3.6Rs and it's likely at least many hundreds of other users of all the various Magnepan models also have become frustrated trying to integrate subs and given up.
Heck, I was on the verge of throwing in the towel trying to use subs with my 2.7QRs when I, thankfully, decided to give it another try by buying the $2,800 Audio Kinesis Debra 4-sub distributed bass array system on a free 28-day in-home trial basis. I remained skeptical right up to the point of hearing it for the 1st time in my room and system.
This is an honest to goodness true story of that 1st audition about 4 yrs ago: My buddy and I had just spent about 3 hrs optimally positioning all 4 subs and wiring them up. We were both a bit tired and resting when I remembered there was a Blu-ray of the WWII movie Fury still in the player. So I hit play on the remote to see how it sounded on my now 5.4 surround ht system (the 2.7QRs, a CC3 center, 2 in-ceiling Infinity rear surrounds and the new 4 dba subs). I was still skeptical after a couple of movie preview ads had played but they had little to no bass content.
Then a preview of the movie Whiplash came on that contained a prolonged and dynamic full-kit drum solo . This was very well recorded and was being played back as 24 bit/96 Khz hi-res PCM format through my Oppo 105 at a med/high volume level. The entire drum kit seemed like it was actually physically in the room, centered along the font wall of my 23' x 16' x 8' room. The drum solo was so exceptionally realistic, with bass that was felt as well as heard, as it built in momentum to the point of both of us being totally convinced there was a drum kit being played vigorously at the front of the room, without even the faintest hint it may be a recording. When the drum solo ended with a flourish and abrupt stop, it left my friend and I just staring at each other wide eyed in amazement.
No doubt, some readers will believe I'm exaggerating but I'm not very concerned since I really don't think I can overstate how well this dba concept actually performs in my system on music and ht. In fact, the only valid criticism I or anyone could make is that my AK Debra dba only has flat bass response down to 20 Hz at 113 db, which means it can't completely reproduce the lowest octave of 16-32 Hz. But there's always the option to build a custom 4-sub dba system with all or a few of the subs being larger and capable of flat bass response down to 16 Hz or even lower. I'm unaware of any recorded content containing bass this deep, however, so I'm currently satisfied with flat bass extension down to 20 Hz. and only hearing/feeling most of the bottom octave.
I also understand your satisfaction with the bass performance of your 1.7is after mounting them on Mye stands, adding the jumper and fuse, changing to Bryston amps and selling your subs. Your 1.7is 3-way Magnepans only have bass extension down to 40 Hz +/- 3 db from a quasi-ribbon bass area of 442 square inches compared to my older 2.7QRs 3-way Magnepans that only have bass extension down to 34 Hz +/- 3 db from a quasi-ribbon bass area of 620 square inches. This indicates to me that we both likely experience very similar high quality bass response levels from our speakers. If so, I clearly understand how you'd be satisfied with the bass performance of your speakers without the aid of subs since I was almost satisfied myself.
But the truth is that most would probably consider our speakers by themselves as a bit attenuated in the deep bass, especially by those having large point source cone type woofer drivers in their large floor standing speakers and those using 1 or more subs.
I believe that almost anyone, including you and I, would consider the bass quality of our Magnepan speakers as being exceptionally high but somewhat limited in bass extension, dynamics and impact. My main point is that I'm certain that almost anyone, including you and I, would consider the bass quality of our Magnepans with a dba system as being very close to state of the art with good deep bass extension, high levels of detail, seamless integration, powerful dynamics and impact along with a seemingly effortless quality that is perceived as amazingly life-like and natural.
I'll conclude this book by noting that we're unlikely to realize there's missing bass content if our system can't even reproduce it, sometimes we just don't know what we don't know and you can audition an AK Swarm or Debra dba system free in your home for about a month. It'll take you less than a day to set it up and know I speak the truth, which leaves about 29 days to return it if you're unsatisfied. I know I'll never be buying another sub in my lifetime.
Tim