Maggies with a subwoofer system - optimization?

I need advice on how best to improve the midrange and base on my Magnapans (1.6qrs)My idea is to relieve the panels of base duty ( only feed the signal above 100 to 150 hertz to the panels and let my Swarm subs take the low end signal). I assume my midrange will improve, and the solid base performance via the sub system will fill in well. I now run a Krell S550i integrated into the Maggies, and the Krell Pre output into the DaytonAudio SA1000 Subwoofer amp.

Any feedback is appreciated - will I lengthen the life of my panels? Am I wasting my time? 

Does that Krell have a preamp input so you can use a high pass filter going to the Maggies? If it don't then you will still be using the Maggies full range!
Hi Tom,

Your cutoff target may be a little high, I’d suggest around 80 Hz instead.

Your approach is good, but you would need to limit the signal before the amp. This would greatly increase the dynamic range of the amp and panels, and yes, reduce the strain on them. I’m not sure if it will improve the life of your panels. That depends on how they wear normally and how much bass you were going to push them to begin with.

The best advice I have for you however is to rely on automatic room correction to setup the crossovers and EQ, if any.


How is that done without a high pass filter between the amp and preamp? Just curious!
I do not have a preamp input on the back of my Krell S550i, so a high pass filter will not work with my existing setup. I am just trying to tweak my system to another level. I mainly play Jazz but occasionally I push the system with Blues (Bonamassa)

i know my panels only go down to about 45 hertz - I have been integrating the Swarm into the system for a couple of months and it sounds great with the Maggies - actually listening at lower volume levels out of the Krell as the sub system is filling the bottom end effortlessly. My imaging on stand up bass and Hammond B3 organ passages has become amazing (Nora Jones - Till We Meet Again is blowing me away).

Thanks for the input.
How is that done without a high pass filter between the amp and preamp? Just curious!

@yogiboy  Unfortunately you have found the problem, you can't. :)

Adding a subwoofer without also limiting the amp output will not reduce the load on the main speakers at all.
Optimize the bass of the Maggies by placement of the Maggies. Perhaps 6 feet out into the room. I like the Maggie bass so I would run them full range and it sounds like you are happy with your subs. 
Short answers- no, it will not lengthen the life of the panels, and yes you are wasting your time. 

A much better way to get the improvements you want is a combination of vibration control using Townshend Pods under the speakers and subs, and acoustics using Synergistic HFT Speaker and Room Kits. If you like what you are hearing now you will freak when you hear it with these.
Hi Tom, if I understand your situation correctly, there is no way to highpass filter the signal before your Krell amplifies it and sends it to the Maggies.  

Theoretically you could roll off the bass going to the Maggies by placing a highpass filter in between your amp and the Maggies.  This may or may not be a net improvement.   

FORTUNATELY we have Stereophile's impedance measurements of the Maggie 1.6qr, which makes the necessary calculations possible. 

The impedance of your Maggies is amazingly smooth across the bass region, and I estimate that it averages about 5.3 ohms across a two-octave region centered on 80 Hz.  For a second-order 80 Hz highpass filter, I'd suggest about 265 microfarads of capacitance with 15 mH of inductance on the shunt leg.  NO electrolytic capacitors allowed.  I do not suggest a first-order filter because a) it will have too much effect north of the crossover region; b) it will not protect your speakers as well; and c) it probably would not blend as well with the lowpass filter in the SA-1000 amp. 

IF you end up with a bit too much output from the Maggies in the crossover region, I suggest reducing the amount of capacitance and just leaving the 15 mH inductor alone.  If you need a bit more output from the Maggies in the crossover region, I suggest increasing the amount of capacitance and again leaving the inductor alone.  

No guarantees of course that this will be a worthwhile net improvement.   My advice is free and worth EVERY penny.  

That's what I was thinking. The cap/inductor thing I mean. ;) 

Bear in mind the whole signal will be going through that, and quality caps that size are big money. Cheap caps? The whole point is improved midrange. No way you're getting that with cheap caps.
Vandersteen subs would be your best way to add lower frequencies. IMHO.
But, as you have a Swarm sub system, I think you would be best served by contacting Doug Shroeder ( douglas_schroeder ) here on Audiogon.

I think he would have the best info for you.

This DIYer on Youtube, is the best Hifier on YT.
He knows his stuff and backs up everything he  says with demos.
So here are the DWM's in action, go to 7:30 to hear his ideas on the results.
He also has  another video showing the other bass towers with some sort of electronic xover working with the Magnepans. 
If I find it I'll post it.
My Defy has biwires, so I may run one set to the Little Ribbon Speaker and 1 set to the Seas dual W18's. 
And if needed will add a  Seas Crescendo tweeter,,just won 1 (single) off ebay today at $180, for testing,,, 
Not sure if the Little Ribbon  Speakers need the tweet.

**Littl** Ribbon Speaker in action, 
WOW *Little** yet HUGE on soundstage.
Highs off the charts.
can 't wait to order a  pair.... And yeah I can hear th performance  of these speakers THROUGH my $10 comp speakers.

If they are anything even close to what I imagine I'm hearing,,,I'll be a  happy audiophile camper
Here I found the YT vid
My tech geek disses this DIYers ideas as *bunk*
I'm  with Hifi Guy
THis guy knows his stuff
I just have to figure out what electronic xover to add and how to add it, as my tech wo't have anything to do with it.
To me it makes alot of sense, cutting some of the lowest hz's off the Magnepan , thereby giving more voice to upper bass/mids and highs.
makes alot of sense.
Not sure how to go about it.

@tom8999 @millercarbon Tom, I have a pair of Magnepan 1.7i on my solid state system driven by a pair of Bryston 28B3 monoblocks. As for lengthening the life of your Maggies? I think that is overthinking things. As for the bass, if you are like me, you were in Maggie bass-denial for some time. You don’t know what is missing because you haven’t heard it. Let me cut to the chase. Maggies are incomplete speakers. They need to be considered as part of a “kit”. Unfortunately, not all the components of that are obtained from Magnepan. Here is what I recommend to be in the Maggie “kit”:  1. The Maggies of your choice. 2. The Mike Powell Ag upgrade jumper and tube (in lieu of fuse). 3.  A pair of MyeStands or similar for the Maggies. 4. A pair of REL T/9i or the new T/9x subs connected to your amp(s) with high level input cables, preferably good ones (Kimber or Analysis Plus). That is the “kit” IMO. Of course I recommend an amp or monoblocks with lots of power for dynamics, transients and headroom plus good speaker cables. Do all of that and you will be in LOVE with your Maggies! Done. 
Hi. I’m listening to Quad ESL63s using a Hsu sub to handle the load below 90 Hz. I’m listening thru a Marantz AV preprocessor, so I use the sub crossover settings in the preamp to handle the integration. It’s working great to my ears (and to others who hear my rig). Using the prepro allowed me to experiment with different crossover frequencies until I found one best for my room. 
Getting the low frequencies out of the Quads really freed them up. Maybe the same for Maggie’s?  YMMV…
This sounds like what the OP is looking for. Video based on LRS but the basics apply 

Start at 23:28 

May I suggest  an 80-100 Hz crossover with the maggies? I used such on Model II, 1.7i, and LRS. Midrange clarity may improve if you have been playing it loud. Use music you normally listen to at a normal volume to adjust the volume level of the subwoofer. Enjoy!
I was unable to realize the full potential of my Magnepan 1.6QR until I bypassed the factory crossovers and replaced them with a Marchand tube electronic x-over in a bi-amplification arrangement using a Carver 275 and a pair of Carver 350 monoblocks.  To this I added one ML 800 sub with a plan to add three more.  The results, so far, have been amazing.
1.7i’s have a major peak at 70 hz, which is why people have a hard time matching subs to them.

The important thing here is to stop the bass going to your amp, something as simple as Harrison F Mods can do that inline, which are inexpensive, just like a preamp would with a small filter, and so your amp will not waste any energy throwing watts into to your speakers that they cannot reproduce in the first place, plus a little extra by adjusting that up to 80-100 hz.

You will find that it is much easier to integrate the subs smoothly by knocking off the 70 hz spike.

Yes, the mid bass and midrange will improve when the deformation of the diaphragm of the panels is not reproducing as much bass, since the membrane is not traveling as far on the bass notes away from the magnets, which causes distortion in the upper frequencies by trying to reproduce those with fluctuating Tesla units. 

What makes a ribbon and AMT drivers so accurate, the the surface of the sound source between magnets, a relatively constant magnetic field, makes panels so finicky, the surface in front of the magnets, creating a variable energy field. 

Mathematically this is significant, as the energy increases and losses are squared with distance from the magnets.

A First Watt B5 will fix the issue. External Crossover

It features a two pole (12 dB/oct) low pass filter variable from 20 to 300 Hz in 20 Hz steps, and a high pass filter with 1 or 2 poles (6 or 12 dB/oct) which is also variable from 20 to 300 Hz in 20 Hz steps.

The woofer channel also has a 2 pole high pass filter for the woofer with a 6 dB equalization “bump” at 20 Hz. This is useful for extracting a bit more output at the bottom of the audio range of any loudspeaker, particularly open baffles, and functions as a subsonic filter below 15 Hz.

The full range high pass channel offers choices of shelving equalization curve (also known as “baffle step correction”) for full range drivers, variable from 250 Hz to 2.5 Khz with shelving at 0, -2, -4, -6 and -8 dB.

The active circuits are JFET buffers, most of them simple source followers without feedback. The distortion and noise are quite low, and the bandwidth is very wide.

I have one. They are around. Pass quality, no frills or hair raising looks.

FULL of WiMa caps and Vishay copper resistors. Single ended input and output. Separate dinky doo PS. That one I haven't figured out yet. BUT it's very quiet and it's a Pass design.. There is a lot of quality there.

1 - 1500.00 used only. You can talk him into making you one though.

Cool thing is it dosen't mess with impedance on the passive xo. Adding anything on the speaker cable side "WILL" mess with the factory XO, you have to be careful there..

IF you want a great option.. FW B5, The B4 should work.. 3 way if I remember.


Unbelievable......Well Not Really

Totally ignoring the subject matter that the OP’s wishes to discuss a certain individual takes the opportunity to ‘Peddle’ these products yet again...blatant spamming...Ergo SPAM which is not allowed...Will the Mods act ...obviously this post wont survive very long....

” A much better way to get the improvements you want is a combination of vibration control using Townshend Pods under the speakers and subs, and acoustics using Synergistic HFT Speaker and Room Kits.“
Has anyone else biamp-ed Magnepan 1.6/1.7, bypassed factory crossovers, used electronic crossovers and added subwoofer(s)?
@avitacom I have added a pair of REL T/9is per above. Made a huge difference! Please see my post above.

Yes, several years back I added a Bryston 10B active crossover and another (matching) two channel amp to the 1.6's I have, gutting the passive crossovers. It was fairly simple (I could do it and I'm electronically challenged). Well worth the trouble and expense (about $2,000 for the used amp and 10B). Since the 10B is only a 2way crossover I just ran the sub through it's passive crossover. Blended pretty well IMO and very enjoyable with all kinds of music. The ultimate would be getting a 3way crossover to also feed the sub. I think Pass and Marchand are the two analog options available and there were several digital options at that time, DEQX was one, but I went simple to see if it helped the 1.6's and my system. Net - well worth the time and expense.

From what I understand, the 1.7's no longer have bi-wireable binding posts so it would require a fabricated set-up for the binding posts. Also, didn't Magnepan add a super tweeter to the 1.7's? That would complicate the wiring as you'd need something to act as a crossover for the tweeter. 


The 70 hz bump. Yep. I got lucky. I mounted some fiberglass/foam acoustic panels on one reflective wall and it tamed the bump. Shouldn't have, but it did.

My 1.6's are going on 20 years old now and still going. No sign of delamination. And I listen at very loud levels. From my reading over at the Planar Asylum it seems room atmosphere is the biggest variable in panel life. Salt water (as in close to the ocean) and direct sunlight have been pointed out as two that will shorten panel life (cause delams').

Good luck with Dukes swarm. I've read a lot of good things about the setup.
@don_c55    But surely the Townshend Pods will improve the base as well as the bass.    Sorry, couldn’t resist. 

I have installed biamp hookups on my 1.7i's as the bass panel is run full range on them with direct wiring to the positive and negative terminals.

But none of the other things you mentioned. Feeding the midrange/tweeter combo, I have heard people call it a 2.5 way speaker, separately helps, but well above the range the OP describes.
Everyone - thank you all for the input on my quest to keep tweaking my Maggies and my new Sub system from Duke.

i have reviewed the multiple YT recommendations and I agree that I may make more gains in my sound looking at better speaker isolation and room treatments - I am going to abandon the idea of limiting the low frequency (under 150 hertz) going into my Maggie 1.6qrs. I feel ‘as is’ that the system sound has integrated very well -  I guess my reason for concern started when I saw some minor delam of my copper wire ( 4 spots near the buttons on the panels about 1.5 in in length) on the back of my 1.6qrs and considering their age (18 years old).

I am very happy with my sound after the addition of The Swarm. 

Again - thanks for the education.