How to tell/confirm voice coil is 100% functional?

[Eviljacket]

So I’m rebuilding a few subs, 2 of them were matching L7’s and he needs the coils to match. One was locked up, wasnt told anything about the other and pulled a newb move (still learning but more then capable of rebuilding, this is my 3rd rebuild salvaging stock parts) and deconstructed both without testing the other unknown. It looks perfect, each coil ohms out at 3.4 and neither jump around, when testing they start at about 3.6 and settle down to 3.4. So how can I test to confirm and make sure it’s good? It s a coil from the 11S12L7 model line. Hoping some guru might know some OG technique to test the coil without having to actually build with it lol.

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[1aespinoza 10+ year member]

Hoping some guru might know some OG technique to test the coil without having to actually build with it lol.

It is only a coiled single strand of wire. I do not think there is any other test other than continuity to ascertain it's functionality. Maybe the color is a telltale of abuse.

 

[Buck 5,000+ posts]

@hispls

 

[metalheadjoe 10+ year member]

You're on the wrong site, unfortunately.

 

[hispls 5,000+ posts]

each coil ohms out at 3.4 and neither jump around, when testing they start at about 3.6 and settle down to 3.4.

That's just your DMM it probably has an auto-range feature.

If coils are visibly intact, nothing is dented, bent, or cracked, and no outgassing issues (look for bubbles on the former on the inside) and your impedance reads within 10-15% of published number they're fine.

If you had to cut back the leads make sure to scrape away the shellac so you have nice shiny clean copper for contact before trying to solder and crimp that to your tinsel. As you rebuild be sure to pop the terminals with a flashlight battery (if you're assembling in the frame) or confirm you have a proper connection with DMM before you glue up the triple joint to make sure you did in fact get a good connection everywhere.

You may have to gently unwind that lead to get enough up above the spider to connect to your tinsel.

 

[Eviljacket]

That's just your DMM it probably has an auto-range feature.

If coils are visibly intact, nothing is dented, bent, or cracked, and no outgassing issues (look for bubbles on the former on the inside) and your impedance reads within 10-15% of published number they're fine.

If you had to cut back the leads make sure to scrape away the shellac so you have nice shiny clean copper for contact before trying to solder and crimp that to your tinsel. As you rebuild be sure to pop the terminals with a flashlight battery (if you're assembling in the frame) or confirm you have a proper connection with DMM before you glue up the triple joint to make sure you did in fact get a good connection everywhere.

You may have to gently unwind that lead to get enough up above the spider to connect to your tinsel.

Ty bro, really appreciate the insight and tips, helps a lot