Did you mean same volume of copper wire? Same weight will be 1/3 volume and twice resistance. Same volume of copper wire will be 2/3 resistance, but tripled mass. At bass panel will be higher efficiency, but lower roll off point.
For electrical & weight issues, Aluminum....Ever notice how the Aluminum wire failure pitting corrosion looks just like Salt ? ..And Not just in one isolated spot or area (like the floor level) but erupted All over like it was wiped or sprayed on ?? ...Chemistry speaking,...did my VC wire somehow convert into Aluminum Chloride (salt) ?? ....I'm no chemist, but,...if thin Aluminum wire was to have a slow but insidious skin Allergy,...Diluted Chlorinated water moisture, trapped beneath a rubberized skin would certainly get the job done !! ....But how could That worst nightmare happen ?? ......Googling deep thru the search layers,....Hmmm,...a clue,..just maybe......FastBond 30NF alias "Polychoroprene" == Waterbased Chlorinated liquid Rubber ??? ....Can anyone verify that ? ....If a Fact,...I'm Not getting that stuff anywhere near my Maggie's upcoming Rewire (all 300 ft) & looking for a just as thin, but much Less reactive adhesive--binder ...
Anyone have a suggestion for a good, thin-medium viscosity, Solvent based synthetic rubber like adhesive-binder ?? Must Not contain "Chloro" type description !!
Just try a short (say 10/20 cm) sample to verify, but regular rubber/neoprene contact cement applied through a thin nose tip, forming a bead along wire, so it surrounds/insulates it and glues it to base membrane "should" work well.
I mean fresh cement, maybe somewhat thinned with a little Xylene/toluene, so it wets both wire and membrane well, and you apply the minimum amount possible, then capillarity sends it where it´s needed: between wire and membrane.
You are not using it as contact cement but as a regular "dry hard" one, so no tackiness to help you, so you must find some way to hold it in place while it dries (minimum overnight, preferably 24 hours)
I guess it follows a zigzagging pattern so you may momentarily hold ends in place with some adhesive tape, run the bead along long sections, let them dry, then pull tape and glue ends.
At least I would do it that way.
I mean fresh cement, maybe somewhat thinned with a little Xylene/toluene, so it wets both wire and membrane well, and you apply the minimum amount possible, then capillarity sends it where it´s needed: between wire and membrane.
You are not using it as contact cement but as a regular "dry hard" one, so no tackiness to help you, so you must find some way to hold it in place while it dries (minimum overnight, preferably 24 hours)
I guess it follows a zigzagging pattern so you may momentarily hold ends in place with some adhesive tape, run the bead along long sections, let them dry, then pull tape and glue ends.
At least I would do it that way.
Thx guys,......That's a lot of good helpful info for me to sort thru before I start spreading glue & laying wire !!
Hey Matt.....That DC bias (maybe a few amps) magnetic centering--holding sounds like Magic ......I've got to try that !! ...An extra hand or 20 is always useful !!
Yes Sir JM......the plan is the narrowest glue line Between the membrane surface & wire bottom--sides...
I found that the wire stuck well in the 3M spray. Of course the panel was horizontal at the time. 😉 For the tweeter wires it seems to be enough, but maybe not for the woofer.. I agree that thinned rubber cement might be a good way to seal and lock the wires. There are some YouTube video about doing that.
But careful about too much direct current, don't burn up your wires!
But careful about too much direct current, don't burn up your wires!
Here's one person's suggested values, edited for brevity:
http://www.integracoustics.com/MUG/MUG/tweaks/alex.html
Tweeters . . . 12 volts at 1.75 Amps . . . You could probably get away with little more, say 2.5 amps, but that's about it.
. . .
Midrange/Bass areas . . . If 12 volts at 1.75 Amps is not enough to keep the wires in place, you may want to go higher on the amperage, but just pay attention to how much heat the wires are producing.
http://www.integracoustics.com/MUG/MUG/tweaks/alex.html
Tweeters . . . 12 volts at 1.75 Amps . . . You could probably get away with little more, say 2.5 amps, but that's about it.
. . .
Midrange/Bass areas . . . If 12 volts at 1.75 Amps is not enough to keep the wires in place, you may want to go higher on the amperage, but just pay attention to how much heat the wires are producing.
I surely wish i didn't have to touch these factory virgin panels....Even using illuminated 5X examination lens, I can see & feel the wire's Entire unobstructed radial profile view with NO apparent evidence Any adhesive buildup layer except at the very last inch over the wire end loops......If I didn't Know the wire was glued on,....I Couldn't tell by visual inspection !! ....Yet,....Somehow,....there's No delaminated or loose wire, ..after 45 yrs !!
I have had Tympanies that worked for 40 years before going bad. Magnepan changed the adhesive a few times. What they use today seems to hold for a long time. The wire is not naked aluminium, it is coated. The 3M 30 NF Neutral is water based. I have used it without the 3M spray adhesive. 3M 30 NF on both the Mylar and the wire and let dry before pressing them together seems to work, it is a contact adhesive.
Thx for helpful info Roger....I believe Magnepan started using 3M 30NF around 2005....Do you Know of any 30-NF applied panels where the Enameled aluminum wire still Corroded & pitted open circuit ?
I also have a pair of MG 3.6 made in December of 2003, with the old adhesive but still working. They started to use 3M 30 NF in 2005. Delamination can depend on temperature, humidity, sunlight and how they are played, and other things. Aluminium is sensitive to fatigue, the vibration can speed it up. Very old wiring will corrode at some point even in friendlier environment.
Delamination aside,...has anyone seen any 3M Fastbond 30NF factory treated (built after 2005) Magnepan speaker panel Voice Coil wire corrosion ??
Sunlight is DEADLY for any polymer, since UV light depolimerizes most anything, degrading it, so damaging to adhesives, membranes and enamel, just give it time.
And yes, old Aluminum enemy is flexing fatigue.
Mechanical "working" (such as repeated bending or even wire drawing implicit in fabrication) hardens it, and makes it fragile, so even if wire was thermally treated after drawing to make it soft and pliable it will eventually harden up and so be prone to cracks.
I guess in theory flat membrane speakers do not flex but are expected to move as a single piston, not sure it fully happens in practice, and any difference in movement between nearby areas by definition will flex it, even if to a small degree.