Building Crossovers

[Mike Burke]

I have been searching for any info or sites that address putting crossovers together. Not designing them but arranging and placing the components together.
Soldering tips, inductor placement , terminal blocks and any does and don'ts of building them. I see some that are neat as can be an some that are just thrown together....looks like a nightmare. I would like to be a little neater about arranging and soldering mine.
Are there any tutorials around about this ?
Thanks

[Geoff Millar]

Hello

There are some clips on Youtube, but there are two tutorials on Parts Express' site which I found very useful.

The first is on laying out and soldering together Curt Campbell's 'Tritrix' crossover, and the second, for Curt's 'Aviatrix'. The Tritrix is simple, with 5 components and the Aviatrix, a bit more complex. But both videos give you hints on soldering, laying out the board and wiring.

These videos can be found at the bottom of the Tritrix or Aviatrix product description page: or at:

https://videogallery.parts-express.c...r-kits/page/2/

I found crossovers intimidating but these videos made it much more understandable. My crossovers look awful, with great blobs of solder etc but they seem to work and there aren't any short circuits. I just put the components on a piece of Masonite, which seems to work OK.

Good luck


Geoff

[Wolf]

This will help...


It's an analysis of the coil arrangements and measured output of the adjacent coil. V2 is the best coil arrangement as you can see.
Be mindful of materials, as aluminum adjacent to coils can decrease their value, and steel adjacent to them can increase their value.

I like using pegboard and zipties, and sometimes E6000, for the application of parts to a board. Try to get components arranged where few jumpers are required. Above-board or below-board connections are up to the builder. If you bolt the coils down, use nylon bolts and nuts, or real brass bolts and nuts. Some brass sold at hardware stores is really an alloy and has steel in the mix, so use nylon as a sure thing.

This is a generic layout below that I came up with that suits most 2-way applications. It keeps the resistors on the outside for better airflow. It is one of many examples.



You can search for Curt Campbell's 'Nodal Analysis' document to go along with this.

Some capacitors are constructed inside thick metal aluminum tubes; some examples are Audyn Plus, Jantzen Z-Superior and Z-Silver, and Obliggato gold Premium. These apply to the aluminum reducing the value of the adjacent coil if set close together.

As to soldering, use a pretty hot iron in the 30-50W range or so, and apply heat with an 1/8"-3/32" broad solder tip to the pre-attached leads of the pending joint. After a few seconds when the joint is hot, apply solder to opposite side of the joint. I like the 60/40 rosin-core solder, Kester is okay. The solder will flow towards the heat source. I recommend using a ceiling fan, table fan, or even working outside to avoid direct inhalation of the fumes. I also recommend a brass 'dish-scratcher' base to wipe your tip as needed. Your iron won't have to reheat after cleaning that way.

I also highly recommend a cheap zip-tie gun for zip-tie installation, and to use the steel-barbed ties for coils if you wind your own.

Use a DATS, WT2, WT3, or LC meter and DMM to measure your components and get consistent values for your applied usage.

And lastly- MAKE SURE THE XOVER FITS THROUGH THE ACCESS POINT. You can make false panels, bolt-ons, multiple board sections, stacked boards or daughter boards; just so the xover can be easily installed. Outboards are less problematic in this manner, and just a chassis with an input pair and Speakon output to match the Speakon input on the cabinet is the easiest MO.

If you have any other questions, I'm sure the members of this forum can help you resolve them.
Happy building!
Wolf

[tomzarbo]

It's not a bad idea either to make a computer mock-up of the layout with the components actual size so you can arrange them before you build it. You can use Word to do this and when you make the shapes it tells you the size of them after you make it so you can be sure the components are actual size.

I second Wolf's "make sure it fits" comment. Also, it's a great idea to fashion a way to mount the crossover in the cabinet before you finish the cabinet if you can.

See this post: http://techtalk.parts-express.com/fo...44#post1291344
Wolf's comments here are spot-on. Scroll down a few and you see I followed his advice, though you can't see the single screw yet.

Basically, it fit in the driver opening and one screw near the woofer hole was all that was needed to keep things nice and secure. Easy in-easy out.

I make generally ugly crossovers. I do put thought in to them to make sure things are laid out logically and with a minimum amount of interactions between inductors, but pretty doesn't make it perform better, so I don't worry about it much. I do however, understand why some guys make them nice, and I dig the look a lot.

TomZ

[jhollander]

Good tips above, to add on, I've found my crossover for the second speaker is alway better than the first. So to improve my first attempt I:

1. Cut the board the x-o must fit on first.
2. Figure out where the x-o mounts.
3. Determine what direction the speaker and power leads come in
4. Lay out the components on the board, loosely twist the leads, and move them around for the best fit
5. Add wire to components and strip back the inductor enamel to get a good fit on the board
6. Final mock up is to twist wires together and check fit again on the board.
7. Where clearance is not an issue look to stack components
8. Figure out where the wire ties could go and drill holes in the board (sometimes I skip the wire ties)
9. Use tape to hold components from moving for soldering
10. Use a terminal block during mock up but attach it last to the wires and board
11. Trim the wires going into the terminal block so they only go halfway in.
12. Twist and solder stranded wire ends going into a terminal block, it's just easier.
13. Solder and glue components to the board
14. Trim wire ends
15. Screw board to the cabinet

[donradick]

Wolf - wow - a MasterClass from a crossover master! SAVED.

Guest -- yeah, that's pretty much how I do it.

One thing that you will find, is that quickly connecting to the Ground is a problem.
Once you have gotten your components somewhat arranged, start thinking about
how many connections to Ground you will need.

Waiting until the last moment and trying to solder 10 wires together at one point
will be a problem. I know this....

At one point, I made my crossovers by putting all the leads and connecting wires
on the bottom side of the board. This resulted in a number of sessions of picking up
a crossover and flipping it over and over while I traced connections.
Now I leave all the leads and connecting wires on the top side.
More messy, but MUCH easier to verify and troubleshoot.

[Sydney]

...One thing that you will find, is that quickly connecting to the Ground is a problem.
Once you have gotten your components somewhat arranged, start thinking about
how many connections to Ground you will need.

Waiting until the last moment and trying to solder 10 wires together at one point
will be a problem. I know this......

Utilizing a Busbar concept will resolve this.
One example:

[Mike Burke]

Thanks to all that posted...some Great information here. I really appreciate it !!! That will certainly get going in the right direction. I have put a couple simple cross overs together already but they were pretty simple
I have built a couple sets of Heliums.
Now I am working on a set of Nano Neo's. A few more components.

Some Good stuff here...Thanks

[Pete Schumacher]

Here's a pic of a 3-way XO I recently put together. Yeah, I could have stood up a couple of the air core inductors on edge but they looked like there was enough separation and Wolf's data above shows decent attenuation of cross coupling.

I'm showing this because I was able to get all the components laid out and wired up using nothing but the component leads. No ground strip or input strip required. Just take your time to lay everything out so that the common components at ground and input can be near each other.

[Wolf]

Utilizing a Busbar concept will resolve this.
One example:

Normally, I agree with you, Sydney, but in this case I don't think this is the best route. When I was doing the Cecropia xovers, I was amazed at how much the steel in the conventional barrier strips affected coil values. In this particular instance, I went with Euro-blocks because they did not seem to affect the value much if at all. For initial mockup of a xover, or a template or proto-board, I think barrier strips are fine. For the actual xover, if you use terminal strips, Euro versions are going to be a better idea.

Edit: Additionally, I try not to use terminal strips in the actual xover. I'll use direct soldered leads for the connections. In the Cecropias, I had a 2-layer construction, and needed to have the top to bottom jumpers, as well as having the strips for the multiple coil connections and the switch panel access point.

Later,
Wolf

[Sydney]

... I was amazed at how much the steel in the conventional barrier strips affected coil values....

One example:

The concept was to use a buss as a common node ( to alleviate soldering issues - not necessarily with that particular example ).
I've fabricated simple buses from copper bar strips ( no pictures available )

[Wolf]

I might as well repost the xover pictures for it to show what I mean....

Coils above the equator are used one at a time. This is the tweeter layer.


On the back of the top- I attached the Euro strips. You can see in the next photo how close that places them to the woofer coils on the bottom layer.




The Strip lays right across the coil in the ENE position, and did not have a detrimental effect.

Completed, Supreme + Xpad version:



You can also see the switches atop the middle of the tweeter board. This was to keep them away from the tweeter coils as there are steel parts in the switches.



You can see the 'Xpad' daughter board next to the large blue cap. Sometimes to get things tight, daughter boards are a good idea.

You can also notice that I had to separate fields of coils from the top and bottom layers so those didn't interact. This took a long time to construct.

I'll post more in a few in the next post...
Wolf

[Wolf]

The concept was to use a buss as a common node ( to alleviate soldering issues - not necessarily with that particular example ).
I've fabricated simple buses from copper bar strips ( no pictures available )

Sure- I've used copper rods before to make this really easy. The copper also won't affect the inductance of the coils.
Wolf

[Sydney]

There are more Coils and Caps in those pics than I've purchased in 45 years

[Wolf]

Here's a not so clean photo of the layout I posted above applied to a xover. I had to increase the size, but it doesn't obscure what types the parts are.

Edit: Found a better image....


It allows expansion by stacking caps for 3rd order electrical on the tweeter. The stuff in the upper right corner is a notch on the woofer, and I added a C across the resistor on the tweeter on the front left. This allows right angle placement of the coils. If you want a 3rd order on the woofer and don't have a notch, the second coil is placed flat in the upper right hand corner where the notch coil is.

Sometimes layout can't be placed in this fashion as pictured, but I find it to be pretty versatile.

Later,
Wolf