Planar magnetic from Wire to Foil test

[WrineX]

I converted my planar magnetics speakers from wire to foil. since i wanted to replace the foil anyways. to see what happens in the frequency domain once and for all !

The replacement itself
YouTube

and a simple measurement of the FR in room and some Tunes

YouTube

and a mirror for people from a region the tunes are blocked
Fullrange Planar magnetics - Results and music - Video Dailymotion

Green is foil pink wire. as expected either increase tension or increase conductor vs mylar to make the top end smoother (upp the breakup frequency by the looks of it) confirmed jeeej and lose some output but i already knew that hehe

 

[tyu]

Happy Holidays …..looks sound great...thanks for your work an the info...
So I had to pull Some All wire,1987.....MG1c Tuff for me to get my head around this sound was around in the 1970s....These have the wire an mylar... facing to the back..
Using My ML CLS an Apogee Stages Speakers as a reference point to day.....like my old conrad Johnson PV2, PV5 Big tone magic tube preamps....these just biger brother of the SMga…
Sound Vary Sweet....can play vary loud with 50 tube watts...Theres a texture...I don't get with the ribbons...or ESLs.....vary quick...lot of fun for sure...heres MG1c what thay look like.....

I think Magnepan well have to come out with a new pr of all wire maggys..hehe..

Look like there thinking of using small round drivers...with there true ribbon....in a new line....."30.7 for Condos"


Magnepan Doubles Down | The Absolute Sound

 

[WrineX]

foil does the same here as wire just extents a little further.

yeah magneoan going open baffle woofer...... it is a damn shame they screw there roots and ideas the whole thing is build uppon

 

[tyu]

Well yes....your real Aluminium foil dose extents the topend…..the QR not so much...well not to my ears....Magnepan foil sounds Dead to my ears....I gess Apogee used so much aluminium on there bass drivers...deal with the lose of output...but this is were the medel sound come in to pic....always trade offs...

As to the New Magnepans open baffle ribbon setup....why not...tuff sales for any speaker biger than a cell phone....today

I got call to day about a pr of Apogee Calpers…..I ask the guy how much $$...he side he just wonted them to go to a good home….

What freash Hell is this...hehe

Only time well tell....Calpers about the only biger Apogee I would take...
Stage is 60lbea...the Calpers got be right at 80-100lbea

Keep the good work...your small ESL sound great also

 

[WrineX]

Why would a flat wire sound dead compared to the insulated counterpart from the same metalic material ?

 

[RogerGustavsson]

The QR drivers use aluminium foil just as WrineX did. The difference is that the wider foil WrineX use "shorts" a bit of the possible tension of the Mylar. If the goal is to improve the upper range of the driver - it is a move in the right direction. For low bass, it is a differnt story, you need as much stroke as possible.

Apogee use a different way of tensioning the diaphragm (that is also corrugated). it does not rely on the tension of the Mylar alone as is the case of the Magneolanar type of driver. Apogee use a more expensive line up of magnets, sitting further away from the diaphragm. The diaphragm can move several millimeters Before hitting the magnets.

 

[tyu]

Why would a flat wire sound dead compared to the insulated counterpart from the same metalic material ?

The QR foil is not pure Aluminium like you an Apogee used!
The foil I got from Magnepan for repair of the tweeter in a pr of MG1.6r
I was also told by Magnepan this same foil was used for bass in the 1.7s theres only one QR foil...
QR foil ...Well starch before it brakes... its has a mix of other material in its foil
that's why it sounds the way it dose...dead, is not the best word...Not the same foil!...

I gessed that magnepans found if its foil was all Aluminium...it would brake to ezy...as there panels were made.

I had a pr of MMgs here for repire ….one panels bass was not working ...when I found the bad wire in the crossover....... I got the bass working aging...the mid-bass wire an the foil faceing out the front like all the New panels do.... the bass-mid wire was way brighter than the tweeter foil.....

Like all the older all wire panels sounded... when turned around to the wire in front.... had a bad high frequencies peak
never sounded right...well to my ears.

 

[WrineX]

Shorts possible tension? You can have any tension you want. Apogee is a complete different speaker indeed. A magnepan uses mostly a far bigger surface area then most apogees. So it does not need to have that same xmax. Higher tendion in the foil or wires/foil closer to one and other makes it lose controll of the foil in between rise upwards in freq range . I also wonder with apogee how much tension there is horizontal simce tsome of them where tuned to 40 or 50 hz. Depending on the width of the unsupported foil this says to me it still had quiye some tension. Or it would act more like ribbon with very low resonance

 

[irribeo]

I had those MG1c's long long ago, my friends were very impressed with them

 

[lowmass]

yep your measure shows the basic difference. The large area un-driven sections of mylar when a wire is used are trouble above about 300 hz. make the conductor wider and it gets better.
Make the conductor cover ALL area ( except small slit) and it will be even smoother midrange.

Yes in theory the magnet flux lines are not aligned with conductor as well directly over top of magnets BUT there is drive force none the less. As well there is a better damping effect from the sandwich construction over all area rather than the low self damping nature of the raw, tensioned mylar.

Sure there is some loss of sensitivity BUT in my experience its worth it.

BTW as for the "condo" Maggie, looks like a good idea to me BUT one issue I have always had with every dipole Ive ever built, I still have to get the mid/ tweeters way out into room to be at their best. AND no matter how thin an sexy the mid/tweeter panel is, IF its way out away from rear wall ( min 3-4 feet) then its still dominating the room.

 

[tyu]

I had those MG1c's long long ago, my friends were very impressed with them

Well yes...I have the MG3a,MG2.5r,the MG2c....these are 6' tall but these MG1c with the legs we all have love to hate....lean back sound vary good...I like stock sound best + there ezer to drive...I am a all tube amp panel guy today.


Over 5 years ago I got this QR foil....for repires an to put this foil in a pr of MG1.4 all wire two ways...that's tweeter was out....did not work well vary low output..I posted about my findings on this foil years ago.....

This old Wire type panels rocks...long as its mylr an wire..is playing out the back.

Here a pic of the foil not vary good .I well try to get a better pic..you can see it been handeled an twested a lot it dosen not breat ezey…..an if I were making-saleing panels...I would have to have them work...pure foil well break ezey...just look at Magnepan true ribbon tweere...small wind can rip it up

 

[WrineX]

yep your measure shows the basic difference. The large area un-driven sections of mylar when a wire is used are trouble above about 300 hz. make the conductor wider and it gets better.
Make the conductor cover ALL area ( except small slit) and it will be even smoother midrange.

Yes in theory the magnet flux lines are not aligned with conductor as well directly over top of magnets BUT there is drive force none the less. As well there is a better damping effect from the sandwich construction over all area rather than the low self damping nature of the raw, tensioned mylar.

Sure there is some loss of sensitivity BUT in my experience its worth it.

BTW as for the "condo" Maggie, looks like a good idea to me BUT one issue I have always had with every dipole Ive ever built, I still have to get the mid/ tweeters way out into room to be at their best. AND no matter how thin an sexy the mid/tweeter panel is, IF its way out away from rear wall ( min 3-4 feet) then its still dominating the room.

Above 300 hz ? Hihi i hope not more like 7 khz forvthe bass panel

 

[RogerGustavsson]

Shorts possible tension? You can have any tension you want.

What I mean is, with foil there will be less uncovered Mylar. The aluminium foil cannot stretch, only the Mylar. If there is less Mylar that can stretch, that will also limit the maximum SPL at low frequencies.

 

[RogerGustavsson]

The foil I got from Magnepan for repair of the tweeter in a pr of MG1.6r
I was also told by Magnepan this same foil was used for bass in the 1.7s theres only one QR foil...

Are you sure? I have three different foils from Magnepan, I cannot see anything else than aluminium. Maybe, I am blind. I also have the foil Magnepan use for their ribbon tweeters, it is very thin.

 

[tyu]

Are you sure? I have three different foils from Magnepan, I cannot see anything else than aluminium. Maybe, I am blind. I also have the foil Magnepan use for their ribbon tweeters, it is very thin.

All I have done is post my one mans findings.....What Magnepan has changed...don't know.
But when the 1.7 came out I got a new pr..at full price...The QR foils Sound not For Me!...but if you don't go...you don't know.

But I have Apogee,ESLs an the Magnepan true ribbon as my Reference point.

looks like Magnepan doing just find with out any more of my money...an that's great....I have my older Magnepans thay sound great...lot of fun...
highly recommended...I paid $10 Us for the pr of MG1c off creagslist..the last of the all wire type...made 1987...

 

[irribeo]

I remember the foil was very very thick, or maybe the layer of glue was very thick (panels were MGII not MG1 btw also a one panel design, I think the III had a separate tweeter). I enjoyed my friends enjoying them, personally I liked esl63 better, but for my friends it was no contest, the Magnepans were much more impressive, amps then were Luxman anniversary)

 

[AVWERK]

Shorts possible tension? You can have any tension you want. Apogee is a complete different speaker indeed. A magnepan uses mostly a far bigger surface area then most apogees. So it does not need to have that same xmax. Higher tendion in the foil or wires/foil closer to one and other makes it lose controll of the foil in between rise upwards in freq range . I also wonder with apogee how much tension there is horizontal simce tsome of them where tuned to 40 or 50 hz. Depending on the width of the unsupported foil this says to me it still had quiye some tension. Or it would act more like ribbon with very low resonance

FWIW -the Apogee Divas magnet to foil spacing is 4.064 MM (.0160”) with 174 magnets per speaker

Regards
David

 

[tyu]

Well ESL like the quad 57...to my ears,like a good working pr of first Ml CLS are better ….not as ezey to drive..well over lode if pushet ...these old maggys roll right thought...but I can only live with one speaker for a day are two....then I put diff one in..i got the Stages in my head now..... .just trying to have fun with good sound...like you I would think...

 

[Rob Dingen]

Shorts possible tension? You can have any tension you want. Apogee is a complete different speaker indeed. A magnepan uses mostly a far bigger surface area then most apogees. So it does not need to have that same xmax. Higher tendion in the foil or wires/foil closer to one and other makes it lose controll of the foil in between rise upwards in freq range . I also wonder with apogee how much tension there is horizontal simce tsome of them where tuned to 40 or 50 hz. Depending on the width of the unsupported foil this says to me it still had quiye some tension. Or it would act more like ribbon with very low resonance

Hi the Apogee Full Range has a woofer panel of about 30cm average wide and 180cm high and a gap of 5mm.
At least the one I build

Rob

 

[WrineX]

That you build or rebuild ? Since that would be one of the bigger ones.