Please could someone check my first attempt at crossovering....

[steve rb]

Thanks folks, been going mad here trying to figure out what I'm doing. Hope I might have got it, but before I commit solder to wire, please could someone give it a once over as I'm clueless at best...
(oh and I know the wire needs changing...And I will muck about to get the coils apart, but for now, just the principle...)

Thanks very much!

P17 is given as follows :
(I've gone with his 2nd order tweeter version with a 0.39 coil in parallel - I think...)




And my interpretation of this is as follows :

[Fatmarley]

Following all those bits of string fries my brain, but I think it's ok.

[AmDismal]

Looks OK to me.

The only way you'll do damage is if you miss out the tweeter capacitor - and since there is a huge screw holding the tweeter voice coil, I doubt you could do much damage to it anyway!

[steve rb]

Thanks folks - it was the parallel wiring which I was struggling with, especially the low end - the positive in is connected to the driver positive in AND the driver negative in (albeit with a capacitor inbetween), that just doesn't seem right, won't that create a short?
Also, the top end, 2nd order version said to wire a coil 'in parallel' but where in parallel...above was a guess, and again the negative in is connected to the driver positive in AND the driver negative in (this time with an inductor inbetween).

[Fatmarley]

I'm not very good at explaining things, but i'll try and explain how I build circuits.

I label every junction with a number. So the for the tweeter circuit, the signal-in and capacitor would be labeled (1) Then the other side of the cap and the positive terminal of the tweeter would be (2) and so on... Then all you have to do is join all the number together - easy !

[steve rb]

I'm not very good at explaining things, but i'll try and explain how I build circuits.

I label every junction with a number. So the for the tweeter circuit, the signal-in and capacitor would be labeled (1) Then the other side of the cap and the positive terminal of the tweeter would be (2) and so on... Then all you have to do is join all the number together - easy !

Novel idea, and I can count so that helps!
Problem is knowing which junction to number which, for example, I'm really not sure how the coils connect for the tweeter and bass as it defies my, admittedly very limited, electrical beliefs to cross-circuit something like this, have visions of fried amps and drivers if I've done it wrong.

[Fatmarley]

Does this help ?

http://s219.photobucket.com/albums/c...SABAAlnico.jpg

[steve rb]

Does this help ?

http://s219.photobucket.com/albums/c...SABAAlnico.jpg

Thanks Matt, neat, yes it does actually!
If I wanted to change to tweeter crossover to 2nd order as he recommends, he said to 'add a 0.39uF coil in parallel' - where would it go in this case, after C3?
Appreciate everyone carrying me through this, it'll click eventually!

[Fatmarley]

Thanks Matt, neat, yes it does actually!
If I wanted to change to tweeter crossover to 2nd order as he recommends, he said to 'add a 0.39uF coil in parallel' - where would it go in this case, after C3?
Appreciate everyone carrying me through this, it'll click eventually!

Yep, After C3 and shunted to ground (The same as C3 on the woofer circuit, but with an inductor instead of a capacitor)

[steve rb]

Phew! OK, I'll try and optimise the layout a bit, but I'm governed by the 240x190 junction box they are going in. Then good to go!

[guypettigrew]

You need to make sure the two coils are at right angles to each other.

Also, before moving to a second order crossover it's worth building it as shown and having a listen.

You have ALNICO magnets in your drivers. Amazing!!! They should give you superb results.

Finally, to find the +ve terminal on a driver--but not a tweeter--connect a 1.5v batttery to the terminals. When the +ve of the battery is connected to the +ve of the driver the cone will push out. If the battery +ve is connected to the -ve terminal it will suck in. It's important to get the drivers wired up as shown. If you have the bass and midrange both connected the same way round you'll get overpowering bass.

Have fun.

Guy

[steve rb]

You need to make sure the two coils are at right angles to each other.

Also, before moving to a second order crossover it's worth building it as shown and having a listen.

You have ALNICO magnets in your drivers. Amazing!!! They should give you superb results.

Finally, to find the +ve terminal on a driver--but not a tweeter--connect a 1.5v batttery to the terminals. When the +ve of the battery is connected to the +ve of the driver the cone will push out. If the battery +ve is connected to the -ve terminal it will suck in. It's important to get the drivers wired up as shown. If you have the bass and midrange both connected the same way round you'll get overpowering bass.

Have fun.

Guy

Here's hoping it will be both fun and successful!

Got my layout sorted I think.
Will hot glue it in then wire up.

[guypettigrew]

Pretty!

Looks like you've gone for at least a second order crossover. There's far more components in the box than the original circuit diagram!

What circuit did you decide on in the end?

Guy

[AmDismal]

There are lots of components as the capacitors are paralleled to get the higher (68uF and 80uF) values. These Russian PIOs are quite cheap - about the same for the set as it would be for a basic motor capacitor. It's the second order on the tweeter and bass, first on the mid.

Steve - I assume that a couple of 'wires' have come loose, especially on the mid? There should be no connection from one side of the cap to the other, or it won't do much!

[steve rb]

There are lots of components as the capacitors are paralleled to get the higher (68uF and 80uF) values. These Russian PIOs are quite cheap - about the same for the set as it would be for a basic motor capacitor. It's the second order on the tweeter and bass, first on the mid.

Steve - I assume that a couple of 'wires' have come loose, especially on the mid? There should be no connection from one side of the cap to the other, or it won't do much!

YES! - ignore the string on that second pic, I'm assuming I know what I'm doing with the wire now, that was just me trying to get the best layout....
Where the inputs go straight to the -ve of the drivers, did you use speaker cable straight through or also take the feeds through your 'winding wire' into the crossover? Guessing direct connect with the intended speaker cable may be better, but then I don't want to 'inbalance' anything by using winding wire on one half of the co and not on the other - guess it makes no difference really though...

[steve rb]

Also, before moving to a second order crossover it's worth building it as shown and having a listen.

Incidentally Guy, I'm all for trying the two, but just curious - what differences would one expect between a first and second order crossover?

[AmDismal]

Where the inputs go straight to the -ve of the drivers, did you use speaker cable straight through or also take the feeds through your 'winding wire' into the crossover? Guessing direct connect with the intended speaker cable may be better, but then I don't want to 'inbalance' anything by using winding wire on one half of the co and not on the other - guess it makes no difference really though...

I went through the junction box - if you didn't, you would have trailing wires from the speaker, surely?

I wouldn't get too precious about one extra connection, tbh

[steve rb]

OK - after what seemed like hours, I've done the first CO. Had a bitches own game with the enamelled magnet wire, solder just didn't stick and I'm not happy with the connections. Am going to re-do it with some silver plated copper hookup wire....

[avinunca1]

Re- enamelled magnet wire. I assume you burned the conductor ends and scraped the enamel off first

[steve rb]

Re- enamelled magnet wire. I assume you burned the conductor ends and scraped the enamel off first

Yep, but such a faff and still dodgy IMHO...