Subwoofer options for Magnepan with crossover betwen pre and amp?


I'd like to offload the bass below 50hz to a subwoofer through a crossover placed between pre amp and amp; believe this will (a) help with stabilizing the Prima Luna amp by eliminating low bass clipping (b) remedy the lack of weight in the low bass with Magnepan 1.7's. Has anyone found a combination they liked for around $2k? I've seen Vandersteen 2WQ's mentioned, I suppose separate amp/crossover TBD with Magnepan DWM panels are another path. My main concern is a clean merge of the subwoofer with the SQ of the Magnepans
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The lower you go, the more difficult things get. I can think of a dozen subs that would sound well if properly integrated.

That means room treatment, crossover, and EQ.

If you want the simplest, go with a relatively small sub, with a good auto-EQ feature.

I would also suggest upping the crossover point to 70Hz. This will get your PrimaLuna up above the meat of the bass in music. (let the flames and differing opinions begin!)

Best,

Erik
The JL Audio E-Series subs have high-pass and low-pass crossovers and controls. They are wickedly fast and blend with Maggies very well (I've heard'em. If it were in my budget I'd have a pair of E-110s or E-112s.
^^^
When I wrote "I heard 'em" I actually heard a pair of JL Fathom F212s mated to a pair of Magnepan 20.1s. Still, the integration was seamless and turned the 20.1s into a very dynamic full range system for a fraction of the price of the Wilson Alexandrias in another demo room.
Not a fan of bass assist above 50hz..the maggies do well on bass color but hit problems in pedal tone octaves. One of the reasons I bought MG 1.7s was because as a tuba player I could hear they got the mid and upper bass right for timbre and articulation. Power wise with KT150s, the only time I hear clipping issues is when pedal tones and low fender bass are involved.
Not a fan of bass assist above 50hz..the maggies do well on bass color but hit problems in pedal tone octaves. One of the reasons I bought MG 1.7s was because as a tuba player I could hear they got the mid and upper bass right for timbre and articulation. Power wise with KT150s, the only time I hear clipping issues is when pedal tones and low fender bass are involved.
I also have Maggie 1.7s and have them mated to small subwoofers. In my case they are discontinued Mirage MM-8s, which have a long-throw  8" driver augmented by two long-throw passive radiators in a sealed cabinet. The active driver has a ver deep frame to allow the long excursion and a large magnet. The surround is a patented design that allows for long, well-controlled excursions. And the internal power is over 300w RMS (each), 1,200w peak. The diaphragms are all aluminum, so they are very light and stiff.

It doesn't offer a high pass crossover to the mains, but the continuously variable crossover can go as low as 50 Hz. I'd take it to 40Hz if I could. However, the sub controls also include a 0-360 deg. phase control. For awhile I was getting a hump around 80-100 Hz, which made little sense because the Maggies are so clean at that frequency and the subs' upper limit was set to 50 Hz. I figured there might be a phase problem. So I put on my mono copy of "Sgt. Pepper's" and cued up "A Little Help from my Friends." I chose that because Paul's bassline is very melodic and hops back and forth across that 50 Hz line. I listened to one channel at a time. Very quickly I was able to adjust the phase knob on one sub to make that hump disappear. Then I did it with the other channel. Since it was a mono signal it was little surprise that the phase setting on the second sub was the same. After that my subs and panels have sung as one.

These are the speakers for my LP-based stereo rig. Depending on the LP's mastering, sometimes the subs help a lot, e.g., if the bass is rolled off or the music is large scale orchestral pieces and big band. Other times the Maggie's sublime upper bass is all I need for small combo acoustic jazz. 

Anyway, for your situation I recommend you have very fast, powerful subs with a continuous crossover and phase dial (not a toggle), and preferably a high pass crossover as well so you can roll off the bass signal to the Maggies to increase power handling.

Here’s a post Paul McGowan made on the PS Audio website, in one of his blogs:

"There are many great subwoofers available today. Perhaps my favorite is REL out of England. But even as good as REL subs are, they don’t quite live up to the Nth degree afforded by a properly designed servo version. That’s always been a mystery to me, why servo subs aren’t more prevalent".

Having owned the Infinity RS-Ib (six 8" servo-feedback controlled woofers per channel), and now owning a pair of Rythmik F15HP sealed subs and a pair of GR Research/Rythmik OB/Dipole Subs (both of which include the Rythmik Direct Servo-Feedback circuit), it is to me as well.

I use Rhythmik subs with MMGs (rotated with Ohm 100 omnis). I’m 100% pleased with the pairing. However, I use an Audyssey equipped pre-pro as a preamp. I know that some will reject this idea on principle, but IMO it’s the easy, sure fire way to get seamless integration between planar/omni speakers and subs.
Magneplanar has their own bass panels that might be a good thing to listen to.  IIRC, tho they are reinforcements to bass not extensions lower to the next octave down.
If you have the room, and are patient, another option is the bass panels of the old Magneplanar Tympani bass panels. Both the T-I and T-IV models consisted of three 16" wide x 6’ tall panels, two of which were for bass only, and they make great subs for modern Maggies! I say patient because they have become pretty desirable, more people looking for them than are selling them.
Just to throw another option into the mix, have you considered infrasonic generators? The Maggies are fast, so you want fast sub-bass which can keep up. Aside from possibly the Magico QSub 15, the Wilson Benesch Torus Infrasonic generator is the best ’subwoofer’ i’ve seen. My friend has a pair in his $500k system with a pair of Magico S7’s and they blend in seamlessly & work a treat, which is impressive considering the big price disparity to the Magico QSub 15. The Torus also comes with an outboard crossover/amplifier.
I am a big fan of the Vandy 2Wq.  I own a pair, but not using them with panel speakers.  I used them first with Vandersteen 1Cs, and now with Ohm Walsh 2000s.  They continue to delight and provide deep, full, tight, accurate bass, with a seemless blend with my mains.  I did upgrade to the HP-M5 (?) crossovers, which offered a real improvement in transparency and resolution over the basic in-line filters.
There is no one sub that can offer a smother in room bass response then
 a pair or even 2 pair.
The Vandersteen 2WQs have been great with Magnepans
 they hook up at speaker level and unload the main amp from heavy lifting in the bass, their unique hi pass allows the whole systems distortion to lower dramatically improving transparency and clarity.
 Best JohnnyR
Magnepan and Vandersteen dealer
Ignore Johhny's/audioconnection's advice at your own risk!  In my view, he's the best in the biz.  

(No affiliation with audioconnection--aside from being a customer.)
I was wondering about this 'crossing over' thing. I currently just send dac output to the amp. (Gustard x20 -> magtech) I spent a fair amount of time troubleshooting the USB output of the pc feeding the gustard. Finallly settled on a custom USB card driven by an external linear ps and the sound is good. Now adding a sub to this setup can be done at the speaker level or the line level.
1) I do not understand how adding a sub at the speaker level lightens Maggie 's load. It is a parallel electrical connection at the binding posts so the Maggie sees no change in voltage or frequencies presented to her.

2) a line level connection through a Y connector presents the same issue

3) a preamp w bass management and eq as well (emotiva?) seems the only way to lighten Maggie 's load. But I am concerned about adding another component in the chain with its a/d conversion, digital processing, and then d/a conversion. But I guess if I have a pc as the source I can just run Dirac on it for the eq. Which brings me back to the eq method. I am leaning towards rhythmic subs with the peq amp option.
I have two Rythmik F12G with my 3.7i's, and they integrate fairly well.  They're connected to my ARC Ref5SE line out.  I have a slight dip at 70hz that I haven't figured out how to remedy yet.
limniscate, you're a perfect candidate for the Rythmik/GR Research OB/Dipole sub. Details on the GR website and it's AudioCircle forum threads.

Your in Austin, ay limniscate? Check out an ol’ pal of mine from San Jose, Cornell Hurd. He fronts a Western Swing Band, and plays around town regularly. Cornell’s a great songwriter---Junior Brown for one has recorded a song of his.

Regarding calling Rythmik, for the OB/Dipole sub you want to call Danny Richie at GR Research. He and Brian Ding at Rythmik collaborated on the sub, but it’s Danny’s baby. He’ll tell you all about it; Brian Ding sells the DIY kit, but recommends his own sealed and ported boxed subs in preference to the OB/Dipole. You probably already know the G in your F12G refers to GR Research. The G woofer has a paper cone, the standard F12 an aluminum one. Danny feels the paper-cone woofer provides more resolution and a more natural timbre than does the aluminum.

@bdp24, yep Brian was nice enough to let me borrow a F12 and F12G for about a month.  I definitely preferred the G version and bought 2.

Brian's quite a guy. Danny too. Brian found the OB/Dipole sub to be too lean sounding, without the weight he expects from a sub. But that leanness is one reason it works so well with dipole speakers. And their dipole figure-of-8 radiation characteristic matches that of dipole speakers, one reason for that leanness. OB's excite fewer room modes than do omnipoles, resulting in less "room boom", the "overhang" in bass notes some people blame on subs when the real cause is the room itself. Without the low bass reproduced by a sub, the room won't have it's lowest modes excited by the loudspeaker (which doesn't produce very low bass), hence the room's ability and tendency to boom remains unrealized. Add a sub, and that ability and tendency becomes apparent and audible. Fat, "slow" bass (overhang) is always blamed on the sub itself, whether justified or not. 

I'm about to set up both my OB/Dipoles and Magneplanar Tympani T-IV's in my new room---I'm interested to see the similarities and differences between the OB sub and the T-IV bass panels.

I subscribe to the only good subwoofer for a maggie is to sell it and get a bigger maggie if your going for SQ.
I personally love Maggies in the larger panels, but dynamic bass is something that most folks are used to and want.  Physics can only do so much for a Maggie playing by itself.  

Lot's of folks use subs with them and each time I've heard a sub mated, it wasn't my favorite thing as I heard the difference.  The best I've heard so far has been the Vandy sub's.  I haven't heard the new one, but was told by friend who own a pair or two that they are even easier to integrate due to the bass eq.  Having had Treo's and now Quatro's in my own room, I can attest to the EQ for sure.  If I had.a Maggie panel, I'd probably try two pair as that's the best bass set up for any room.  The set up would be worth taking the time to do I'm sure.  

Let us know what you do.  many options for sure.
Old.but still , just.bulld two open baffle woofer columns. Crossover, a xls2502 more than enough power , to keep them under control good crossover. That's what I am going to do .. 

I have 4 subs running with my magnepan Tympani I. Sounds really good, but I think making a equal line source woofer column at 6ft,, open baffle with minimal baffle diffractions.

4x12 inch or multiple 8 inch, line source fast as it's open baffle. No cabinet coloration, enough displacement (controls are endless that way too) 

Crown xls drivecore series has build in crossovers. I used a xls2502 to keep my jbl 18 inch subs under control. 2500w 4 ohm in bridged mono that amp. 

I don't know if any of you ever thought of doing something like this? It seems like a great idea to me to try,and I will I know myself 😋
@michel1980: Head over to the GR Research website (and their AudioCircle Forum) and check out the OB/Dipole Sub. THE sub for use with Tympani’s (and all other dipole loudspeakers, for that matter), unless you have room for a pair of Tympani T-IV to use as subs ;-) .