Back home, these panels were further cut down outdoors using a circular saw and straightedge. I cut across sawhorses, but don't worry about the saw cuts in the top of them. The tops of the sawhorses are common 2x4s, and easy to replace when they get too cut up.

After that, the pieces were brought indoors for trimming on the table saw. One challenge was to cut each side panel to the exact same length, so I fabricated an outboard stop on my table saw for the long pieces being cut. The last picture in this section shows how the workpiece butts against an adjustable stop to cut all the side panels to exactly the same length.  To provide fine adjustment, a 3/8-16 carriage bolt threads into a brass insert mounted in a sliding wood sled. The head of the carriage bolt serves as the stop.

I used a 3/4" flat-bottom router bit to cut the recesses for the speaker mounting flanges, then cut the center away with a 1/4" spiral upcut bit. Note the use of a backer board behind the baffle. It serves two purposes - it prevents the bit from cutting into the work table surface, and it also holds the centering pin securely for when the final cut is made through the baffle. For this build, I used double-stick tape to hold the baffle to the backing board. In the past, I've used countersunk deck screws in each circular cutout to secure them. Obviously if you use screws, they must be positioned outside of any cutting area. Having a carefully drawn cut plan on each baffle helps prevent mistakes - including the most common mistake, forgetting to mirror-image baffles that have offset drivers.

Later on (but not pictured here), I roughed-up the seating surfaces of the steel Hurricane nuts with a triangular file for better grip in the MDF, then use a drop of Gorilla Glue to make sure they don't spin loose later.

Because the non-glued side panel was clamped in place for gluing the other pieces, then removed, its fit is accurate. It essentially snaps in place when the time finally comes to glue it onto the rest of the cabinet.

(Hindsight Note: the damping material can have an affect on how much bass is present. I sometimes wonder if my enthusiastic application of very thick Sonic Barrier affected the amount of deep bass these are capable of. See the listening notes at the end.)

Because of the size of this cabinet, glue-up required almost every large clamp that I had in the shop.

Not shown was some painter's tape that I used to keep the baffle from shifting position as I punched the locator marks.

Connector bolts with 1/4-20 threads from Woodcraft hold the baffle to the cabinet. The broad heads of the connector bolts spread out the clamping load on soft MDF. They look nice too.

When threading the brass inserts into edge-on MDF, I lightly tighten a C-clamp on the sides of the MDF to prevent splitting of the material.

To provide an equal 1/8" depth for all gussets, a simple jig was used during glue-up.

Crossover component mounting plans were done in CorelDraw software after measuring the shapes of each of them, and drawing the shapes to scale. I find it easy to move around the parts, drawn life-size, in software. This permits rapid optimization of space for the crossover, and eliminates confusion during assembly.

One handy extra benefit of drawing to scale is that I use a printout of it positioned on the crossover board to directly mark holes and locations using an awl.

These crossovers could have been squeezed into smaller boards, but there was ample space in the bottom of the cabinet for them as they are.

Pay attention to the reverse polarity required of the tweeter and midrange when wiring. It isn't noted on the crossovers shown here. I simply wire the red driver leads to Ground, and the black driver leads to "Out", which is the reverse of a normal polarity configuration.

I also included all the crossover adjustment options listed by John Krutke on his ZDF3.5 page. To choose one, I merely move the input wire from one input to another. This beats having to unsolder a component, remove it, and solder in a replacement.

Note the strips of 1/2" pine that serve as mounting rails on the bottom of the crossover boards. I used small brass inserts in the wood rails and mating machine screws to attach the crossover boards to them. The completed assemblies are attached to the cabinet by simply gluing the pine rails to the cabinet walls. It's strong and easy, yet the crossover boards are still removable using the machine screws.

Because the primer is oil-based, I give it plenty of time to dry before painting with water-based General Finishes Milk Paint. I'm a little concerned about adhesion between the two materials, but so far it's worked nicely on two speaker builds.

Close inspection in glancing light usually reveals small imperfections in the surface of the MDF. I use 3M automotive spot putty (green paste in a squeeze tube) to fill the minor divots. It applies and dries very quickly, and sands easily.

After filling and smoothing the imperfections, I usually apply one more coat of Seal Coat before priming.

I use Rustoleum Sandable Automotive Primer because it builds quickly, giving me something to sand into. I use fine sanding sponges for the final smoothing before painting. You can see in the photo how smooth it is with just sanded primer. It must be this way for a professional-looking paint job.

If I recall correctly, I painted these using two coats.

The plinth attachment plate was painted with another General Finishes color. It is mostly hidden from view, but if someone is close to the bottom of the speakers, this reddish paint provides a little contrasting color detail.

To remove the damaged veneer, I used hand planes. I used a jack plane to take rough cuts, then a smoothing plane afterwards to prepare the surface for new veneer. This went very quickly, and was easy to do.

Sometimes mistakes open new doors, and I consider this to be one of those moments. I have since thought of many speaker-building scenarios where the use of hand planes may be the way to go. Instead of using a router to level the MDF at joints, I'll probably reach for a hand plane. It will produce very little airborne sawdust like the router. Also a large hand plane, like a Bailey #7, will level the side of an enclosure much better than sandpaper.

The only drawback to using a hand plane is the slightly rough surface of planed MDF. The texture is perfect for a veneered finish, but the light texture left on the MDF would have to be filled and sanded before painting.

I haven't experimented with high-angle plane frogs or steeper bevels on bevel-up planes to see if it reduces texture on the MDF. That's something I can experiment with later.

After the last coat, I waited about a week, and used #0000 steel wool to rub Johnson's Paste Wax into the surface.

When they were dry, I applied hot-melt glue on the port flange area before pushing them into final position in the enclosure.

I used conical rubber bumpers from McMaster-Carr as feet for the base. They have 1/4-20 threads, so they can be replaced with something else later, if desired.

The crossover can be accessed by simply removing the base, and unscrewing whatever board (tweeter, midrange, or woofer) is desired.

The extra room milled into the baffle around the tweeter made attaching the electrical leads easier.

For the woofers, I used 10-32x1 button head socket screws. These are attractive fasteners. I used high-quality, USA-made Holo-Krome for this build. The difference between these and generic fasteners is noticeable. I purchased these online from MSC Industrial Supply Co.

Mounting drivers without marring the painted surface requires care. If I set a heavy driver onto the baffle and it slides sideways, the surface will certainly be marred. I sometimes use pieces of cloth under drivers while I attach the wiring.

After the drivers were all mounted, the populated baffles were bolted to the cabinet using 1/4-20 connector bolts purchased from Woodcraft. In the last photo, you can see how the weatherstrip gasket material compresses down to almost nothing when the bolts are tightened.

When tightening driver mounting screws or the baffle to the cabinet, I use a cross-tightening pattern as if I were attaching a head to an automobile motor. One screw gets lightly snugged, then I move to one diagonally opposite, lightly snug it, move to the opposite diagonal, etc. Once they are all lightly engaged, I repeat the pattern again tightening more. It might take three passes to get the screws as tight as I want. This reduces any warping that may occur. It also reduces binding on remaining screws that is often encountered  when one screw is firmly tightened before the others. I try to use USA-made Holo Krome fasteners whenever possible, purchased from MSC Industrial Supply online. they are a cut above the imports.

TIP: Sometimes the connector bolts threads don't properly engage when starting them. If they are forced, they will cross-thread the hurricane nuts.  The solution is to insert the bolt, turn it counterclockwise a revolution or two until you hear (or feel) the thread drop into position, then proceed with the usual tightening.

I was very pleased with the appearance of the finished baffles. They are both mechanically solid and attractive.