Speaker crossover question

[dragon1952]

Actually 3 questions. 1) I'm assuming the crossover coils (inductors) don't have any polarity right? They're just coils of wire and it should not matter which direction the current flows? 2) Is the glue just to hold the component on the circuit board or does it provide any other function like insulation, dampening, etc. 3) If a couple inches of the coil came unwound I assume that wouldn't be a big deal?
The scenario would be if a coil fell off of the board and became un-soldered could you just solder it back on without worrying about polarity and then just secure it to the board with a plastic tiewrap.
Thanks.

[Face]

2. Correct, a hot glue gun would fix that.
3. It can make a difference. Wind it back up if you can.

[J_Kennedy]

Let me be the first to ask you to please tell us, the rest of the story... :D

[C3 Audio]

Dragon1952,

You are correct in saying that inductors do not have any polarity and can be placed on the board either way. The glue is to stick the inductor to the board and dampen vibrations that, without the glue might over a long period of time, rub the insulation off the coil windings and change the value of the inductor. I have seen where the coil wire breaks close to the inductor and you need to unwind a single coil to be able to resolder the connection. I would say if the coil became unwound, rewind it the best you can, solder it back to the board and use glue and the tywrap to hold it in place. The coil wire is coated to prevent shorting, so if you shorten the length at all, you will need to lightly sand or scrape off the coating to expose the copper for soldering. Also, shortening the coil by a turn or so shouldn't be a big deal, but it will change the inductance value, ever so slightly, so shorten only if you need too.

Good luck and let us know how it works out,

C3:)

[dragon1952]

Thank you very much :D Actually, the coil was pretty heavy for the small board and the wire pulled straight out of the solder joints and left 2 perfect round holes. Didn't even rip the solder away from the board. I have to assume that possibly the soldering job wasn't as good as it could have been? Those little tiewraps they use get hot and then they get brittle and break. Plus, the heat destroys the glue's effectiveness. Then, a good shock (see definition of UPS) can rip a heavy coil from the glue. I've heard of this happening before. I didn't have to shorten the coil and I did wind it back up and then wrap it with a tie. It just seems to me that the crossover designer or manufacturer could figure out a better way of attaching these things...or make the board a little bigger and beefier?
I did not have a glue gun but may get one and go back in. Appreciate the replies ;)

Let me be the first to ask you to please tell us, the rest of the story... :D

You can probably make an educated guess by now :)

[jakelm]

I have said it before. A hot glue gun was my best Dollar store purchase , ever.


..besides the cheap socks.

[PeteTy]

Ill take a stab.
If there is 1 coil there is no difference
if there are 2 the axes must be at 90degrees to each other so they do not see each other .
this makes them mutual inductors or transformers instead of coils . then the direction and phase does make a difference.


the number of unwrapped turns of the coil makes a difference proportional to (number of turns)/(origional number of turns). chances are these arent tuned accurately enough to worry. stock sizes are usallu 20% steps. the glass reinforced package tape will hold the windings together. 1000ampre turns is about a ton of force so one wire ata time isnt much.

the tieing down should be done with non magnetic materials any steel will raise the inductance. Gyp board screws work fine on gyp board.

loose stuff ina/ona speaker cabinet will act like snares ona snare drum you can definatly hear it.

if its a 3way speaker cabinet you have a circut?board with 6 components 3 of which are heavier than the board. the bobbin the biggest coil is wound on is probably the best thing to mount the whole assembly with. point to point wiring would be better than a board and give less trouble spots. the circut board will change 8 connections to 24 and 3 mounts to 6 .