View Full Version : xover assembly tips
I have two soldering irons, a 0-50 watt variable, and a 100/140 watt gun, but have never done a xover. In the next couple weeks, I have three to do.
The first is Mr Murphys insignia on a PC board, should be easy. The second is for the DA175/DC28F's, a little tougher. The third is an external box to upgrade my maggy MG12's, tougher yet, foil inductor, big caps, and heavy wire.
Couple Q's, is there a direction to coils, how do you solder foil inductors, how do you deal with a lot of things coming to a single point?
Any tips or hints would be appreciated.
01-04-2007, 11:56 PM
The small soldering iron should be sufficient for all of your soldering needs.
There is no direction to inductors. Sure there is an inside and an outside, but no audible benefit will be attained by using one over the other. The same is true of Ďmostí caps and resistors.
Solder foil inductors are a bit harder to deal with. I generally fold/wrap the end around the next component, resistor, cap, etc, and attempt to wick some solder inside the fold to make a good connection.
Many components at a single point? If you canít join them all directly, try using a bit of connecting wire to tie them together to spread them out on the crossover board. This could be speaker wire, or even solid conductor wire as used in house wiring.
01-05-2007, 12:25 AM
> I have two soldering irons, a 0-50 watt
> variable, and a 100/140 watt gun, but have
> never done a xover. In the next couple
> weeks, I have three to do.
> The first is Mr Murphys insignia on a PC
> board, should be easy. The second is for the
> DA175/DC28F's, a little tougher. The third
> is an external box to upgrade my maggy
> MG12's, tougher yet, foil inductor, big
> caps, and heavy wire.
> Couple Q's, is there a direction to coils,
> how do you solder foil inductors, how do you
> deal with a lot of things coming to a single
> Any tips or hints would be appreciated.
> Thanks, Ryan
No direction to coils. If you have 2 closer than about 4 inches, it's best to orient their axes at right angles to each other:
1st one down flat like a doughnut laying down in a box.
Next one standing up like a car tire, aimed right at the doughnut, like it's going to run it over.
3rd one standing upright like the 2nd, but turned 90* to it.
Birds eye view: O -- |
Never worked with the foils before.
Where I have a bunch of wires coming together (like a common ground) I use some old bolt-down push-on connector terminals that I have, and drill a hole through the tabs, bend wires through, and solder. You'll come up with something.
BTW, you shouldn't need the big gun.
01-05-2007, 08:42 AM
Provided Link: http://chadgray.info
Looks like everyone else covered what i usually do.
I will add that i use peg board to mount the parts to. The holes in the peg board give you a place to run zip ties through so you can physically hold the parts to the board. I also use a hot glue gun to glue the parts to each other and the board.
Then i use 1" drywall screws to mount the crossover board into the box. Some hot glue on the board helps to avoid vibration, but i find the hot glue hardens to quick so i usually use the same calk that i used to seal all of the joints and seems inside of the box to make it air tight.
It would really stink to have a vibration inside of the box that would be audible.
01-05-2007, 09:03 AM
For the PCB Xover, you want to be delicate and careful. read the parts and the schematic. Don't use too much solder, and I would use hot melt glue to attach the components to the board before soldering.
For the other one, I would connect and solder first. Where you have a number of wires coming together, for the ground for example, try using a piece of 16 to 12 gauge copper wire, stripped at a few points, and solder each component to one point. The end attaches to the negative terminal.
(Otherwise, it can be very messy trying to solder four components and three wires at a single point. You end up with a mass of metal and you almost need a blow torch to solder. And you can't do that, because high heat may damage the parts. Also, you can relieve that by not using anything thicker than 18 or 20 gauge wire with the xover, and being neat when connecting component leads. Don't wrap and twist too much.)
Try to make everything point to point, except the + and - terminals wires and the + and - wires going to each driver.
01-05-2007, 09:41 AM
Provided Link: http://speakerbuilder.net/web_files/Articles/constxo/xoconst.htm
Since Wayne J's site is back up, I think this is a good time to endorse the "crossover construction tips" section of his webpage. It's not perfect, but it gives you a really solid foundation on the basics of putting one together.
Everybody does it a little differently (some very differently). You have to do what works for you, though.
Just be sure you test the crossovers before you install them (eg: plug them into an amp and speakers, and run music through them. It will sound horrible without the speakers in an enclosure, but it is a good way to check whether the correct frequencies seem to be coming from the correct drivers).
01-05-2007, 09:47 AM
Hey, what they said. Two other things I do:
First, I use a small hemostat clamp on the lead of a capacitor that is being soldered (attach it close to the capacitor cylinder). This acts as a heat sink and protects the capacitor from heat damage. Do you need it? Maybe not, but way take the risk?
For attaching the crossover boards into the cabinet, I have started using industrial/marine strength Velcro (available at HD). A couple of two-inch strips at each end are all that is needed. Works like a charm and easy to remove the crossover if needed.
My 2 cents.
Remember, solder is not there to make the connection for you, it is there to hold the connection together solidly for all time.
If you can't twist the wires together, you shouldn't be soldering them together.
And, unless you really really need the impedance you can find in a large gauge foil inductor, there's not much other reason to. ;)
01-05-2007, 10:24 AM
This is my assembled x/o for Wayne J's Dayton Budget MTM, where I used solid copper wire as a buss for all the negative connections. However, I should tell you I was later warned a copper wire of that length could lead to an antenna effect, though I have not had that occur. The suggested solution was to loop the wire every couple of inches.
01-05-2007, 10:34 AM
Provided Link: Kuzma Krossover Kountry (http://www.partsexpress.com/projectshowcase/xover/xover.html)
The departed, greatly missed Darren Kuzma put this tutorial together when he posted his RS 180 MTM project, the Dr. K's. Very helpful.
01-05-2007, 12:20 PM
As Wayne will attest, my crossovers are somewhat slapdash at best...
01-05-2007, 04:58 PM
> This is my assembled x/o for Wayne J's
> Dayton Budget MTM, where I used solid copper
> wire as a buss for all the negative
> connections. However, I should tell you I
> was later warned a copper wire of that
> length could lead to an antenna effect,
> though I have not had that occur. The
> suggested solution was to loop the wire
> every couple of inches.
how does the random scattering work, Dan ? and what are the chances the components just happen to land in the right place..
01-05-2007, 06:03 PM
> how does the random scattering work, Dan ?
> and what are the chances the components just
> happen to land in the right place..
Not random. Imagine the schematic. Imagine the high pass on a plane just above the lowpass, then drop the components, and stretch them out in an effort to prevent inductor coupling. That's my basic assembly method. It was complicated here because Wayne's x/o has more inductors than Paris Hilton has naughty videos.
lots of great ideas
01-05-2007, 09:52 PM
hey, if you have room to do the scatter method, why not! except for the "aerial" effect of all that wire ;-)))
here's one I did recently which was a tad more space confined
Mr.Thomas Aaron Hero
01-05-2007, 11:57 PM
I didnt have room on one board so I put it on two and ran all the wires and connections on the back side
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