I'm frustrated with trying to find voice coils, and re coning pars in general. I've gotten to the point where winding my own seems like the thing to do.
I have 4 aguilar sdk -10 drivers, 56oz 2"vc,10" 200w 4ohm 99spl
They have two layers of winding, each 43wraps over kapton. About 3/4" ww, I don't have calipers with me, will take exact measurements later.
Because these are Aguilar OEM speakers, eminence model 101140b findING reconing parts has been a nightmare. Eminence-"no."Aguilar-"no".
Keith from craw dad sent me parts, st a good price, but they were for a 3"vc. Hopefully that gets sorted out.
Looking at the failed vc, and the replacement s, they look simple enough, calculate the wire guage by measuring the resistance vs wire length, aND double check t calipers. Seem to be regular round copper.
Seeing what failed, the glue or wire enamel (bass guitar drivers get hot) I think i could make a better one.
The main frequency s I would most care about are between 40hz, and 5000.
I was thinking the improved copper-manganese 5% alloy wire coated with dual layer enamel and polyamide would help keep efficiency high, but I can’t find a source for it, I've only read about it in patents.
I have the cone cap spider.
I would prefer to buy an off the shelf voice coil, where is a good supplier for odd sizes?
I also have two 8 ohm delta 10's in a 210 box, I want to recone them into bass guitar speaker s, the Deltas don't have enough low end, I'll leave them alone for now, maybe wit the 410 it will sort itself out. I want them reconed to 4 ohms so I can run the 210cab at 8ohms, and the 410 at 4 ohms from the same mono amp.
They are getting old.
Back to the Sdk -10, what should I keep in mind if I want these features?
Spl98+
35-5000hz (down to 2k ok)
175w+
Why are voice coils so hard to find? Lack of demand?
I have 4 aguilar sdk -10 drivers, 56oz 2"vc,10" 200w 4ohm 99spl
They have two layers of winding, each 43wraps over kapton. About 3/4" ww, I don't have calipers with me, will take exact measurements later.
Because these are Aguilar OEM speakers, eminence model 101140b findING reconing parts has been a nightmare. Eminence-"no."Aguilar-"no".
Keith from craw dad sent me parts, st a good price, but they were for a 3"vc. Hopefully that gets sorted out.
Looking at the failed vc, and the replacement s, they look simple enough, calculate the wire guage by measuring the resistance vs wire length, aND double check t calipers. Seem to be regular round copper.
Seeing what failed, the glue or wire enamel (bass guitar drivers get hot) I think i could make a better one.
The main frequency s I would most care about are between 40hz, and 5000.
I was thinking the improved copper-manganese 5% alloy wire coated with dual layer enamel and polyamide would help keep efficiency high, but I can’t find a source for it, I've only read about it in patents.
I have the cone cap spider.
I would prefer to buy an off the shelf voice coil, where is a good supplier for odd sizes?
I also have two 8 ohm delta 10's in a 210 box, I want to recone them into bass guitar speaker s, the Deltas don't have enough low end, I'll leave them alone for now, maybe wit the 410 it will sort itself out. I want them reconed to 4 ohms so I can run the 210cab at 8ohms, and the 410 at 4 ohms from the same mono amp.
They are getting old.
Back to the Sdk -10, what should I keep in mind if I want these features?
Spl98+
35-5000hz (down to 2k ok)
175w+
Why are voice coils so hard to find? Lack of demand?
The primary issue is that of the epoxy glass transition temperature. This is the temperature at which the epoxy will soften (also called the heat distortion temperature). If you want to improve on the original design, you will need to use an epoxy which has a higher transition temperature. edit: it also needs to be unfilled, as the filler will compromise the tensile and shear strength as well as make flat layup difficult if not impossible.
You'll find in the literature, that many vc's now use polyimide "glue" for the coils. This material is very high temp stuff, capable of temps well over epoxies. Typical epoxies will run in the 117 to 125 C range, very dependent on the epoxy type. My experience with polyimide was that the stuff required 300C curing (imidize), that would eliminate it from use when a cone is already there.
You can use a polyimide coated magnet wire for the vc, as the enamel might not like the high temperatures. My experience with polyimide is that it can be difficult to get a good bond to, but most of my experience is at 4.5 kelvin, so the bond at room and up may be good enough.
Make sure you really clean the form of old material, you want the lay to be perfect.
You will need a fixture to provide a surface at the tip of the VC, as you will find that the layer jump will give you difficulty. You need the wire to climb up to layer two, and having it pinch against a flat surface is the best way to go. The fixture will be that flat surface. edit: If it were me, I'd machine an end form using teflon, make the body a tight fit to the inner surface of the vc former, and the end flange about 100 mils bigger radius. The epoxy will release from teflon. Delrin may work as well, but I've not tried it in this capacity. I suspect wd40 may work as a release, but you have to take care to not get the former wet with it. A second advantage with a plug fixture of this type, is that if you make it about half a thousanth smaller in diameter to the former, it will aid in preventing collapse of the former as you wind with some tension.
Dry run the setup first, as you want to find all the process difficulties before committing the wind using epoxy. Make sure you get the wind tight and flat. Make sure you can transition up to layer two easily. During the wind of the second layer, be careful of the two dropins per turn that will occur, as you are now spiralling in the opposite direction, and the layer two wire will drop into the layer 1 valleys twice per turn. This will be the most difficult aspect of the layer 2 wind. A small teflon hand fixture to hold the wire against the previous turn here will help.
Once you've mastered the process, do it using the epoxy, you have to wet wind or it will not work. You have to use an epoxy system which will have an extended pot life, as you do not want it to start getting viscous during the wind process. If it does, you are basically through.
When you have completed the layer 2, keep the exit lead tight so that it does not loosen up during cure. Use a small flat tongue depressor cut square and smoothed to remove excess epoxy from the coil surface. If it cures with small spikes or bumps, it can hit the outer iron of the gap. It will be very difficult to remove once the epoxy has cured.
Oh, almost forgot. Once you have cleared the vc former of all garbage, do NOT touch it with your fingers, finger oils will prevent bonding of the epoxy. The same goes for the wire, do NOT touch the wire.
You will have to put mold release on the fixture surface you will use for the pinch/layer transition, or you'll kill the coil during disassembly.
Once you've mastered all the above, you're good to go.
Are you sure it's not just easier to buy new speakers?
jn
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That poly glue sounds perfect, where can I find it? Is there a brand name?
Yes, it would be easier to buy new speakers, mcm has a pretty good ten for about $45, I'm interested in . But after disassembly of several bass drivers I see the same failure, the glue fails every time. Once in about 6 it's over excursion, creased cone, but mainly glue.
I have built my bass, wound pickups, etc, now I want to understand speaker drivers, and then preamps, then power amps. Building, rebuilding is the best way for me to learn.
Those newer fiberglass formers, and fiberglass cones look Rea lly good to me, anyone know how fiberglass compares to kapton former? I'd imagine they are actually kapton impregnated with glass fibers, since again epoxy heat degrades.
. I tried a markbass cab with fiberglass cones and neo magnets, wow.and wow.
This is my first time using them, I have them in an Eden Xlt cabinet, I suppose the problem I have with them is I'm comparing them to stock eden drivers. Eq may help.
they might just be old/getting soft. I read a coating of modgepodge can help , i don't care if it roll s off the high end. Any other treatment that can stiffen paper cines? They haven't creased yet, once that happens they will be toast, I do see a line near the surround starting, 4'6"around. I was thinking polyurethane? Or wood glue ?
And I just got a case of 20 nos cones with surround, so I will be able to test a bunch of ideas. What about using aluminum former? Copper?
Would it be feasible to do an edge wound vc? what wire for that? How about aluminum manganese 5%? I hear that improves spl greatly.
What else will improve efficiency? Higher rms rating is just how tough I can make the coil?
what happens if I increase the winding width? how can i improve xmax? stiffer spider/surround does what?
Sorry for all the questions, if I ask these on talkbass I get yelled at and told to never mess with any part of a driver. I hope there are more like minded/open minded tinker ers here.
56oz magnet, 2"vc
Would it be feasible to do an edge wound vc? what wire for that? How about aluminum manganese 5%? I hear that improves spl greatly.
What else will improve efficiency? Higher rms rating is just how tough I can make the coil?
what happens if I increase the winding width? how can i improve xmax? stiffer spider/surround does what?
Sorry for all the questions, if I ask these on talkbass I get yelled at and told to never mess with any part of a driver. I hope there are more like minded/open minded tinker ers here.
56oz magnet, 2"vc
I used the polyimide stuff about 20 years ago, don't remember the name. I do remember it required 300 degrees C to imidize. Try google. Don't forget, polyimide, NOT polyamid. Two different beasts.
If you have the equipment, make a two part jig. Make the first as a cylinder to ID. Groove each end for a spring ring, drill a 3/8th hole down center, then slit the cylinder 4 times to make an 8 piece tubing expander. A 3/8th rod down the center brings it to ID line fit. Without the rod, the rings bring the diameter down by the thickness of the kerf of the slits. Me, I'd use brass first choice, aluminum second.. But that's because I use an old unimat, and I'd die of old age trying to cut steel that size on it.
You can use teflon plumbers tape around the expander for release. On the end, use a teflon ring holed to fit over the expander, tap the 3/8 rod to fit a metal disk to hold the teflon against the coil.
As to your taking out woofers, try to get a 4 inch vc unit. 45 dollar cheap woofers basically cost too much.
There's lots of info out there on formers and effects, give it a shot.
jn
If you have the equipment, make a two part jig. Make the first as a cylinder to ID. Groove each end for a spring ring, drill a 3/8th hole down center, then slit the cylinder 4 times to make an 8 piece tubing expander. A 3/8th rod down the center brings it to ID line fit. Without the rod, the rings bring the diameter down by the thickness of the kerf of the slits. Me, I'd use brass first choice, aluminum second.. But that's because I use an old unimat, and I'd die of old age trying to cut steel that size on it.
You can use teflon plumbers tape around the expander for release. On the end, use a teflon ring holed to fit over the expander, tap the 3/8 rod to fit a metal disk to hold the teflon against the coil.
As to your taking out woofers, try to get a 4 inch vc unit. 45 dollar cheap woofers basically cost too much.
There's lots of info out there on formers and effects, give it a shot.
jn
Excellent tips,especially Teflon tape for release,I was planning on using aqua dag colloidal graphite,but that stuff is messy and conductive.
By imidise you mean that is the temp it will flow together? The worry I have is I am using a polyimide former, I'm using 2mil kapton film that is very stiff, then winding 2 layers of 43 wraps each around the 2inch former using 30awg double coated wire, round copper with enamel then polimide coatings. I found the highest temp epoxy I could find,and it is very low viscosity. I was planning to barely use enough to get the wire to stick,first with a single dab to hold it in place,,then after 12 hours put an extremely thin layer on the kapton former and then wind the first layer of 43 windings, at this point I'm not sure if it would be better to wait another 12 hours or just finish winding the other 43wraps. I was hoping to find a polyimide based adhesive,but could not. Then I'm planning to place the formers into a digital kiln set of a porous absorbent firebrick so any overflow will wick off. Run the kiln at 300degree centigrade which should cause the polyimide layer of the wire to flow, but I have concerns. I'm worried the kapton(also polyimide but has a higher heat tolerance,and I plan to heatsink the thin parts with aluminium using Teflon a release) former will distort,also concerned the epoxy will interfere with the wire poyimide coating,would I be better off using simple silicone adhesive,a tiny amount to adhere the wire to the former,and the the heat would flow the outer wire layer,or to forget about the oven curing and just rely on the high temp epoxy to do its job.
How do I check my math? 86 windings of 30awg on a 2" (50mms i think) former, will give me approximately 3.9ohms resistance. I can change the wire gauge to get the correct resistance,but that seemed right,and was about the right wound width. They are overhang motors so a few mms off is ok. I don't want to end up with some strange ohms tho.
Also is it at all possible to do an edge wound motor DIY? Where do you get flat fire,and how is it kept flat during winding? I have a pretty good winding jig set up, put a foot controller on the glass lathe,set it to spin at one rpm per second, the wire spool is on a lubricated polished short pain roller,and I will use cotton gloves to guide the wind. 43,then 43. Check the resistance, and start again if I screw up. I'm to understand that as opposed to pickup winding its better to start over than try to solder if wire breakers.
Point me to other threads,I'm not finding much searching,thanks much.
Also I am not grasping foresight your eight part jig. Disregard where I say polyamide,spell correct changes polyimide to amide every time if I'm not careful.
Sent the coils back with a blown one so he can match,I'm using Keith at crawdads speakers, best prices,slow shipping.. I have cones and caps and spiders so I am going to try winding check one came with thumbprint on the voice coil,I'm sure I can do better. The Hampton is stiffer than eminence stock,and the wire seems evenly coated. They were all almost exactly 4ohms too.
Also,could I increase the xmax by using a longer winding width or is that not how that works(sorry knob question!)
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The instructions with the polyimide stuff mentioned imidization, I've no clue what that actually means at the molecular level. Just that the 300 C is far above the ability of epoxy, and probably enamel as well.
I wouldn't recommend trying a 300 C bake.
If you've ever used a pipe expander, that's what I'm basically speaking about. But instead of tapered cones and a threaded center rod, just a 3/8th rod that expands the fixture to line fit on the ID of the former.
I recommend you use the highest glass transition temp epoxy you can find. I' ve used epoxies that transition at about 45C, up to stuff that transitions at 127C. My favorite epoxy is West systems, but I do not know what temp that stuff goes to.
If you room temp cure a two part system, you may have to do a post cure bake to bring the transition point up to the final specified temperature. The epoxy manu should specify that.
jn
I wouldn't recommend trying a 300 C bake.
If you've ever used a pipe expander, that's what I'm basically speaking about. But instead of tapered cones and a threaded center rod, just a 3/8th rod that expands the fixture to line fit on the ID of the former.
I recommend you use the highest glass transition temp epoxy you can find. I' ve used epoxies that transition at about 45C, up to stuff that transitions at 127C. My favorite epoxy is West systems, but I do not know what temp that stuff goes to.
If you room temp cure a two part system, you may have to do a post cure bake to bring the transition point up to the final specified temperature. The epoxy manu should specify that.
jn
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