Magnepan modification blurb..

[ashok]

I came across a web site that supposedly improves the performance of all Magnepan speakers. They have a .doc file that 'explains' how they improve the sound etc.
One section says

"Magnepan changed much of what it had done before suddenly and without explanation, (turning the pole piece rearward, changing the XO's and moving the panels generally more vertical) and I believe (and this is only my belief) that they did this to compete in the ever growing home theater market at a time when 2 channel was dying and HT growing and they had as yet no such dedicated HT models. Doing these things makes their speakers beam more, which makes them seem more falsely dynamic and "brighter", things certain to appeal to the home theater shopper who knows nothing and gives 20 second auditions. One can't blame them for doing what they had to to survive, and doing it was a Rubicon they can't go back over, even though they now have dedicated HT models. However I consider the reversing of the pole piece a ruse and I re-install them forward as they should be. Why? What makes maggies special is the rear wave, not the front one and with the pole piece in the back the bass wave cannot escape as freely as it should resulting in a loss of bass, ambience and over all musicality. (some argue it's also better this way because of the magnets interaction with the mylar (push vs pull) but I tend to discount this) In any case, the vast majority of people when they hear it both ways prefer the pole piece front. "

It doesn't seem to make any sense to me. Am I missing something ?
Open baffle planar speakers have identical front and rear wavefronts. How come the Maggies have a 'restrained' front wavefront and that the rear wavefront sounds better ? " Push vs pull "......?

[SY]

Unlike most electrostats, Magneplanars are not symmetrical, they're "single ended."

[Steve Dunlap]

Originally Posted by SY

Unlike most electrostats, Magneplanars are not symmetrical, they're "single ended."

They are not electrostatics, they are planer dynamic, except for their ribbons. If you want to hear them each way, just turn them around.

[jam]

If I am not mistaken don' the MG20.1's have magnets on both sides of the diaphragm?

[SY]

Originally Posted by jam

If I am not mistaken don' the MG20.1's have magnets on both sides of the diaphragm?

They might. The ones I owned were MG-Is, which definitely had magnets (and the perfed steel sheet) on the front side.

[ashok]

I was under the impression that ALL flat panels with magnets on them ( like B&G) had magnets on both sides of the diaphragm . So that would be identical looked at from both sides. Magnets on one side wouldn't make it linear travel...would it ? That would be like a normal loudspeaker with coil extension only on one side of the magnetic field.

Just realised that the magnets could be located on just one side as long as it had a magnetic path on the other side to bring it back to the front. That would mean a magnetic field perpendicular to the moving film. But that still made it uniform looking at it from either side.

[SY]

Well, it does make for a rather weak motor...

[jam]

I suppose magnets on one side woud work but at the expense of some extra distortion and loss of linearity (at higher excursion).......not being true push-pull. This is probabely less important at lower volumes and higher frequencies.

[moray james]

even if you use magnets on either side of the VC it is still not a balanced drive as is with an ESL. With magnets the closer the VC gets to the magnet the stronger the pull and the farther away the weaker the push, adding a second set of magnets does not change this.

[Pano]

Does the tension of the mylar sheet counteract this to some extent?