Good gravy, it's Friday again?
Been pretty busy with several projects running concurrently. I'm still working on the Heathkit receiver, but I back-burnered it for a while to build these speaker "kits".
And finishing these up can now proceed apace as I *FINALLY* have all the various nuts, bolts, screws, and other misc stuff to wind up this project.
Selling these things as "kits" is dangerously close to false advertising. They're NOT "kits".
They're not even "SEMI kits".
These are a collection of parts packed in a box from which a functioning speaker can (hopefully) be assembled after you the builder round up the rest of what should have been included in the box.
I power sanded the now glued-together-and-cured boxes to get them all squared up, and to make sure the front face was flat. There's going to be a bead of glue between the boxes and the front panel, and while that should be enough to seal the front panel, I still wanted them nice and square.
This is about as good as I can get them with my Flint Knives and Stone Axes.
And then after I sanded them, I blew them out, wiped them down, and dragged them back into the basement to put the foam inside. The box on the left used one piece of foam for the back panel where the speaker terminal plate mounts, while the box on the right used several pieces to cover that area. The left one has a round hole cut in the foam to clear the speaker terminals, while the right one didn't need to be cut because I pieced the foam together from some scraps while waiting for another sheet of foam to get here from Parts Express.
Then I built up the two cross-over networks on some perfboard I bought. I spaced the power resistors about 1/4" off the board with some little ceramic spacers I have for that purpose. The two resistors form a 12dB "L-Pad" (attenuator) for the tweeter, and while I doubt I'll ever run enough audio power into these to heat up the resistors, I always mount them spaced off the board because "Good Construction Practices". I've seen some boards that were blackened and delaminated because of the heat the resistors gave off, but those were usually power supply type applications.
Here's a better shot of one of the networks. The 'white stuff' you see along the coils and capacitors is some "DAP" caulking compound used as "Staking Compound" to hold the parts securely to the perfboard. This should eliminate the parts vibrating against the board, which can make strange "buzzing" sounds emanate from the finished speaker. It also helps reduce any mechanical stress the soldered connections are subject to, helping to keep the soldered connections from fracturing. I used the DAP caulk because I couldn't find my supply of NON corrosive RTV silicone rubber. It's important NOT to use regular "Household Grade" RTV on something like this, as the regular "Bathtub Caulk" stuff releases Acetic Acid as it cures (the vinegar smell), and acid vapors are not something you want floating around in an electronics assembly.
And I even labeled the leads to the speakers and input.....
And since we're expecting temps in the high 50's/low 60's this weekend, I might get the first coat of the "Acry-Tech" rolled on.