SLA Pro - Powered

[Seth]

That does look great. :thumbsup;

[Bruce Weldy]

Well, finally warmed up enough to get back to work.

I cut all the damping material the other night and can't really put off the spreading of PL and assembling of pieces.....

As always, every 90 degree joint in my shop is done with my 90 degree braces.....I love these things.

I shoot my cabs with a brad nailer using 1-1/4" brads. The brace gets attached to the vertical panel, then once the glue is on, I set it in place, getting it all squared up with my gloved fingers before putting the clamps on the bottom piece. Then the shooting begins. Every 3-5 inches is plenty.

After attaching the back to the side, I installed the interior brace. I pre-built the brace instead of doing it in pieces throughout the build. My plan is to use the brace as an additional alignment tool for the baffle later on.

Once this was done, I left in in the clamps for overnight....

[Bruce Weldy]

This morning I started installing the damping material onto the pieces. It's a little strange putting on this stuff before the cab is built like I've done on other cabs, but with a closed box construction, it's got to be now. I tried to keep the spray glue away from the edges where I'd be using PL later.

I had already added the damping to the ends and the brace earlier, so all that was left was the other side. Got that all done and it was time to add the baffle.

It's important to take a little extra time in the build to mark where you want to shoot the brads. I mark a "nailing line" on pieces where the two panels don't come together at their edges. The baffle is a good example of this as it's offset from the front. I also marked the spots to attach to the middle brace. The other thing to mark is the no-go areas.....you don't want the brads to blow through into the holes.

I had built two baffle spacers that were exactly the same length as the distance from the back to the middle brace on the main brace. This, along with my drawn line gave me three points of reference to align the baffle properly and keep it square.

I used those spacers along the bottom when I attached the first side of the baffle, then moved them up and clamped them in while attaching the other side.

You can see my nail line on the side panel..

Letting it dry some....

[Bruce Weldy]

Often when I build boxes, I will leave the last two panels a little oversized so that they are just a little proud of the case. If the box is just a little out of square, you don't have to try and fight it into place. Just line up one corner nice and square, then get the opposite corner lines up and shoot it. Then you can use a pattern bit with a router to trim it all smooth.

This case was actually very square because of the careful measuring and the spacers.

Ends are on and it's standing on its head because the wires from the already installed crossover are sticking out of the top hat hole.

Tomorrow it will be all dried and ready for some routing, filling of holes and priming.

[Seth]

Looks damn good Bruce

The damping material though... the plans call for felt carpet padding, which is different than what you have. I assume you're aware of the difference, but thought I'd mention it just in case you weren't (and for casual reader/future builder clarification). Not sure how effective what you have in there will or wont be. If that is a valid option, I wish I'd known about it. Would have saved me a drive around town to carpet stores looking for felt padding when I coulda just got that style at Lowes.

[Bill Fitzmaurice]

Foam carpet padding is fine. It's higher density than mattress topper foam, but that's OK because it's half as thick.

[Dale Hammer]

Looking real good. Can't wait for a performance review, especially with your T24.

[Bruce Weldy]

When leaving the last panels a little proud, I always try to line up one side nice and flush (if the box is square, then you can get two sides square), this means only having to rout two sides.

This is the before....

You should always make sure and clean up any glue where the pattern bit bearing is going to ride and the top piece where the router will glide. Any bumps in either place will mess up the cut.

After making sure it was all cleaned up with a scraper and hitting it with the random orbital sander (I have two loaded with different grits that live right at my feet on the shelf under my workbench), the router made quick work of cleaning those edges.

You may have to click on the pics to get better detail.

Then came some sanding over whole box to make sure everything was clean for the roundover routing. I got a little tear-out on the top and bottom.....kinda' rare with the BB ply.

But, some Bondo (I use the glazing putty in a tube - available at Auto Parts stores) filled the holes. I hadn't use the tube in quite a while so it was kinda' soupy at first. That means when it dries it will shrink up some, but I always sand after the first coat, then re-apply.

Went out this morning and all the blemishes were satisfactory, so I sanded it with a foam pad sanding block on all the corners - they are cheap, last forever, and don't screw up your corners like a power sander will.

Looks like it's time to finish it.

First off though, I always get a rattle can of black paint and shoot anything that you can see through the port holes. I hate looking in a nice black cab and seeing bare wood or padding or anything that isn't black. Shoot through the port holes and reach inside and hit what you can't get through the holes. It was easier on this build because of the gaping hole in the back.

I'll probably get a couple of coats of flat black paint (that's my primer) on it this afternoon.

[Bruce Weldy]

I always use flat black paint as my primer. A couple of coats builds up the finish some so you don't need as much Duratex. It's only about $15-20 a gallon and it lasts a long time. But, be sure and get flat, not satin, not gloss, etc. Flat black dries very fast. I can start putting on a second coat almost immediately after the first coat.

Here's an exciting pic of the cab with primer on......woohoo!

Now for some process advice......I always start my priming and applying Duratex with the bottom of the cab. The bottom isn't seen and since I always put rubber feet on 'em, they don't get beat up - so I hit the bottom first, then down the sides, back and front with the first coat. By the time I'm through with that, I go right back to the bottom with another thick coat and hit the rest of the box again also.

Even with the humidity at 90%, it was dry enough to put the feet on after a break for lunch. I had already pre-drilled the pilot holes.

At this point, it was time to flip it and start coating the top and sides again. Put on a couple of coats, then had to run downtown to set up a band for their show tonight. I've mixed 'em for years, but I'm turning it over to another guy, so I went to get everything hooked up correctly for him.

When got back it was pretty dry, so it was time for the final coat. Put it on and rolled it out nice and smooth.

My technique is to load up the roller directly out of the bucket by just rolling the roller on the surface of the Duratex. Then I'll roll both directions getting it spread out. Once the coverage is good (always one panel at a time), I roll very lightly over the surface several times to get rid of any bubbles. If there are any little globs or imperfections, I just pick 'em off with my gloved finger and roll over the area. The light rolling really gets the finish level and uniform. It also keeps it from getting too rough. I like a smooth pebbled finish, not rough.

While I'm at it - these are the rollers to use. I've always gotten mine from Leland. I've ever only thrown one away I think. I just wash it with a hose the keep squeezing it out. I've been using this one for several applications and several years.....and there's two more in the package just waiting...

Another tip.....Duratex will last forever.....the bucket I'm using is only my second gallon since I started building cabs 10 years ago. I've still got about a third of a gallon left. To preserve it, take a piece of plastic wrap, lay it over the top, then put your hands inside and push the wrap down until it lays right on top of the Duratex....pressing the plastic tight around the inside of the bucket. This keeps the air out and it lasts a long time. I probably haven't had this bucket open since I built the Jack 15 a year ago.

Here's a couple of bad pics of the cab......I'll let it sit overnight and start assembly tomorrow.

[Bruce Weldy]

Parts may have come from all over the world, but it's getting assembled in the USA!

Started off with the Top Hat..... ooooohhhhh.....aahhhhh....! (Pretty exciting, eh?)

Next up was starting the run the speaker wires.....here's what the crossover and jack plate look like in there. Amp isn't hooked up yet, so there's two more wires that will go to the switch

When wiring series/parallel, you have to go from a + to a -. Since I used some install speaker cable laying around I pulled the wires out of the casing and had red and black. In order to keep all of the positives red and the negatives black, I made these jumpers for the series wiring. Kept everything easy for hooking up the speakers later.

I had already partially wired up the harness to go to the drivers by cutting all the wires to length. So, now I put on all the connectors and zip tied the + and - for each speaker together - so there would be no doubt when loading the drivers.

Side note - all Eminence speakers that use spade connectors (with the exception of some OEM speakers) use a .205 connector. Not 3/16" like the speakons use ( too small ) and not 1/4" (they are too big). So, when you are doing your buying, find the .205 female connectors. I bought a pack of 20 off eBay for about 5 bucks.....worth every penny not to have to try and force on a too small connector or have to squeeze shut the bigger ones.

Here is the harness ready for drivers ....

I've stated this many times over the years, but it's always worth saying again - the most dangerous time for your speaker cones is when you are installing them with a drill driver or even a screwdriver. Keep you baffle cutouts and lay them on the cone while driving the screws.....better to be safe than sorry.

Kinda' looks like pancakes on a griddle, right?

And here we go - all buttoned up except for the grill.....

[Bruce Weldy]

The good news? It fired up and worked first time. I ran it first as just a full range cab....obviously lacking in low end, but not bad at all.

Next up I ran it as a passive speaker being fed from the old Peavey via the crossover in the T24.

Finally had to run it through it's paces in the way it was designed to work. Through the switch to the Sub option, cable to the sub and back up to the top. Worked as it should. The top can definitely outrun the sub, so some EQ will need to be used in the DSP of the Dayton amp to get it equaled out a bit. I'll work on that tomorrow.

I didn't hook it up to a mixer just went straight in with a mono 1/4" from my iPod. Not stupid powerful, but as I turned it up and approach full tilt, it kinda' squealed and cut out. I think the limiter is on in the DSP from when I was testing it the other day - I sure hope that's what it is as I'd like to get more out of this amp.

Overall sound - the SLA is definitely sharper and clearer than the Yamaha SM12V that I've been using in this setup.

I'll know more after I get it outside and get it EQed.

[Bruce Weldy]

My plan is to put a top hat in the top of the T24.....plenty of room right in the center of the box, but it had one of those "oh crap" moments the other day. I realize that since I only built the T24 16 inches wide, it only has one set of braces.....so, you see the problem, right?

I'll have to not only cut a hole in the top panel, but will have to cut into the brace. The only way I can see trying to cut into that vertical piece of half inch ply is with a forstner bit. But, I can see that grabbing and being really hard to get in there 2 inches successfully. A hole saw won't work as it only cuts the sides and wouldn't take out the middle as it went....and it couldn't go that deep.

Anyone have any suggestions on how to cut through that brace? I'm pretty stumped.

If I can't come up with a good way, I might have to build a top hat holder that sits on top of the T24....not what I want, but I may be stuck with it.

[Seth]

It looks like this is the Top Hat you have. You should have the depth available with about a half inch to spare, based on the SketchUp of my 2018 plans.

I'd consider using a forstner bit along with a drill guide like this. I think you can even screw it into place to keep it steady.

[Seth]

You might also be able to get it done with a 3" router bit too.

[Bruce Weldy]

It looks like this is the Top Hat you have. You should have the depth available with about a half inch to spare, based on the SketchUp of my 2018 plans.

I'd consider using a forstner bit along with a drill guide like this. I think you can even screw it into place to keep it steady.

I'm afraid anything short of a really solid drill press won't be stable enough to keep the bit from grabbing and just tearing the brace up.