Overnight Sensation Build -- Two Sets

[Leroy R]

Re: Overnight Sensation Build -- Two Sets

Thanks Ron! I too am impressed with your drawings and find them very useful. I'll be referencing you page here a lot when I start putting my crossover boards together. I want to use your design when building these. Your crossovers by design are a lot more structurally stable than how I did my first crossovers in the Tritrix's. I need to find the hardboard I had left over and get to cutting the boards. My parts are supposed to arrive today.

[Fastskiguy]

Re: Overnight Sensation Build -- Two Sets

A million thank-you's for this post. I'm building a pair of the overnight sensations and electronics and crossovers....are not exactly my thing LOL. With this post I was able to get mine soldered together, tested, and all set to go in the boxes. Not sure if I could have done it on my own....and if so it would have taken awhile. Between the drawings and pictures of both sides it was just great! Thanks again!
Joe

I noticed that you did that in your build -- I'll give it a try.


Now that the enclosures were completed, I turned my attention to the crossover networks. Actually, I began planning the crossover network layout when drawing the plans for the enclosures posted at the beginning of this string. Using a CAD program, my first step was to measure and draw the individual components to scale in top view. I also drew the inductors in side view since one type would be mounted vertically. The components are shown in the area labeled "Component Set," in the drawing. Drawing the crossover network to scale makes it possible to determine how everything will best fit on a small board, and ensures that the completed board can be installed inside the enclosure through the driver openings. Once the components were drawn, I copied the individual components and placed them in a group which was manipulated experimentally by rotating and moving them around. I established three requirements for whatever design I ended up with:

1. The board should be as small as reasonable and fit easily through the driver opening.
2. The two inductors should be placed apart as far as possible from each other, with one mounted horizontally and the other mounted vertically.
3. The input and output screw terminals should be located on different sides of the board to make connections shorter and more logical.
4. The two heat producing components (the resistors) should be separated, i.e., not located beside each other.

Here's a good PE help article on the subject of crossovers -- the orientation of inductors relative to each other is discussed within the article.

Eventually, after moving things around a bit I arrived at three different possibilities, all using compact boards. I ended up selecting the one in the upper right corner, shown within a box which represents the available real estate on the "floor," inside the enclosure. The connections, which will be made up under the board, are shown in red and blue.








In this next drawing, I used the CAD program's auto-dimensioning feature to show where holes would be drilled through the board for wires to pass through, and for screw mounting of the terminals. I should have changed the settings so as to avoid dimensions down to 1/32" which only serves to unnecessarily complicate the drawings. I cut the boards to 3 3/4" X 2 3/4", dispensing with the teeny tiny fractions.




Finally, I used the mirror copy feature to create a drawing showing the wiring as it would actually look on the underside of the board where the connections would be made. I know this is obvious to most, but the dots indicate connections (excluding those showing the location of the screw holes for the terminals), and the little humps indicate that the circuit passes over the wire beneath (most importantly, it does not connect to the wire it passes over). This mirrored view provides a road-map for the connections on the underside of the board.

I should note at this point that the same result can be achieved (planning the layout) by simply drawing the components to scale, full-size, and making paper cut-out to represent the components. Heck, it could even be simpler, but I have this drawing program see, and I just have to use it. Actually, I'll have to admit that I do enjoy drawing things with the two programs I use...



This next photo shows the underside of a template I made for marking hole locations on the four boards I would be making for this build. Note that I marked the circuit on the template -- that makes it easier to check your work as you go along.


1/4" Masonite (tempered hard board) was used for the circuit board. A 4 X 8 sheet of this stuff seems to last forever, even though I find uses for it almost daily. The panel this piece was cut from got wet, but it's still usable for many things (I'm trying to offer an excuse, no matter how lame it is, for the somewhat softened look of the hardboard).

I used European style terminals this time around and I'm very happy with them. They're small, and economical since you can purchase longer strips and cut out what you need. Three connection terminals are not easy to find.

I used hot-melt glue to secure the components on the top-side. I did use a zip-tie for the vertically mounted air-core inductor because it's likely to be subjected to stress. I don't find zip-ties necessary for the other components; the hot-melt glue holds well, and the leads (passed through the board) really provide enough strength on their own. That, combined with the added strength afforded by the hot-melt glue, makes for a very sturdy board.



Here's a view from an angle:


Components should be mounted with their identifying labels up. In the event there's any question about what the component's value is, or should be, the repair technician (that might be you) can easily read the value.

Here's a view of the underside of the board showing the soldered connections. The last time I did this (showed the underside) I got a few critical comments about my soldering. I took them to heart, but I doubt I'll get an A for the work I did on these. Onward and upward, as they say, I guess....



Although not shown here, I used short pieces of dowel to make stand offs for the board. These ensure that the circuitry is held out of contact with the floor of the enclosure.

The boards were installed using hot glue on the ends of the dowel standoffs. Working as I was through the driver opening, it was necessary to make up the wiring that would connect the input side to the binding posts, and the output side to the drivers, before installing the boards. Once the necessary lengths are determined, you can attach the wires to the board terminals, before installing the board inside the enclosure.

[Soundslike]

Re: Overnight Sensation Build -- Two Sets

Thanks Fastskiguy -- I'm happy to hear that the information was helpful. You're going to love the Overnight Sensations.

[Erich H]

Re: Overnight Sensation Build -- Two Sets

The crossover layout is a great help. I'm going to make a link to your post on my site. That will help anyone that doesn't know exactly what they're working with.

[Soundslike]

Re: Overnight Sensation Build -- Two Sets

Thanks Erich, that's nice to know. I'm pleased that people are finding it helpful..

[whipdancer]

Re: Overnight Sensation Build -- Two Sets

On the cross-overs - what are the white wire terminals called (assuming they have a type or name)? I've been all over PE and the web trying to find them.

Thanks!
~Whip

[Soundslike]

Re: Overnight Sensation Build -- Two Sets

Whip,
Sorry it took me a while to get back to you -- I just now noticed your question. The white terminals are called European style terminals. I think PE has them, but I did a quick search as Radio Shack and came up with the following link:

http://www.radioshack.com/product/index.jsp?productId=2103230#

These are the ones I used and they work very well. You can cut them to get the number of terminal connections you need -- three on the output side, and two on the input side.

[RDR75]

Re: Overnight Sensation Build -- Two Sets

I've seen 'em on eBay too....

[whipdancer]

Re: Overnight Sensation Build -- Two Sets

"European style" terminals - that's what i was looking for.

I kept coming across catalog sites that probably had them, but it always seemed like I couldn't find something that looked like the ones in the picture. I was using the wrong terms to search on (wire terminal does not return the same results as European style terminal).


Thanks - i'll be picking some up in the morning!

~Whip

[mrdrew]

Soundslike up there in post #52, you posted a pic of the front baffle with a dado (?) recess cut all the way around. I think it was in relation to flush veneer. It got me thinking about speaker grills though. Have you, or anyone, seen the sides recessed in a non-ugly way, so you don't get that side diffraction from the tweeter vs grill frame? Thanks!